Download 2006 - Illinois Department of Public Health

State of Illinois
Pat Quinn, Governor
Department of Public Health
Damon T. Arnold, M.D., M.P.H., Director
The Epidemiology of
Infectious Diseases in
Illinois, 2006
The Epidemiology of Infectious Diseases in Illinois, 2006
TABLE OF CONTENTS
Reportable Communicable Diseases in Illinois . .......... ......... .......... .......... ........1
2006 Summary of Selected Illinois Infectious Diseases ......... .......... .......... ........3
Acquired Immune Deficiency Syndrome/Human Immunodeficiency Virus .. ........6
Amebiasis.... .......... .......... .................... .......... .......... ......... .......... .......... ......11
Blastomycosis ........ .......... .................... .......... .......... ......... .......... .......... ......13
Botulism ...... .......... .......... .................... .......... .......... ......... .......... .......... ......15
Brucellosis ... .......... .......... .................... .......... .......... ......... .......... .......... ......17
Campylobacteriosis .......... .................... .......... .......... ......... .......... .......... ......20
Central Nervous System Infections ........ .......... .......... ......... .......... .......... ......23
Aseptic Meningitis or Encephalitis of Unknown Etiology ......... .......... ......24
Aseptic Meningitis or Encephalitis of Known Etiology,
Excluding Arboviruses ................. .......... .......... ......... .......... .......... ......26
Arboviral Infections ... .................... .......... .......... ......... .......... .......... ......28
Haemophilus influenzae (Invasive Disease) ........ ......... .......... .......... ......37
Listeriosis ...... .......... .................... .......... .......... ......... .......... .......... ......40
Neisseria meningitidis, Invasive .... .......... .......... ......... .......... .......... ......42
Streptococcus,Group B, Invasive .. .......... .......... ......... .......... .......... ......46
Cholera……………. ……… …….. …….. ……… …….. …….. ……… …….. ……48
Cryptosporidiosis .... .......... .................... .......... .......... ......... .......... .......... ......49
Cyclosporiasis ........ .......... .................... .......... .......... ......... .......... .......... ......52
Ehrlichiosis .. .......... .......... .................... .......... .......... ......... .......... .......... ......53
Shiga Toxin Producing E. coli, Enterotoxigenic E. coli, Enteropathogenic
E. coli .......... .......... .................... .......... .......... ......... .......... .......... ......56
Foodborne and waterborne outbreaks ... .......... .......... ......... .......... .......... ......61
Giardiasis .... .......... .......... .................... .......... .......... ......... .......... .......... ......88
Hemolytic Uremic Syndrome .................. .......... .......... ......... .......... .......... ......92
Hepatitis A ... .......... .......... .................... .......... .......... ......... .......... .......... ......94
Hepatitis B ... .......... .......... .................... .......... .......... ......... .......... .......... ......98
Hepatitis C, Acute... .......... .................... .......... .......... ......... .......….... ... ....101
Hepatitis C, Chronic or Resolved ........... .......... .......... ......... .......... .......... ....103
Histoplasmosis ....... .......... .................... .......... .......... ......... .......... .......... ....105
Legionellosis .......... .......... .................... .......... .......... ......... .......... .......... ....108
Lyme Disease ........ .......... .................... .......... .......... ......... .......... .......... ....112
Malaria ........ .......... .......... .................... .......... .......... ......... .......... .......... ....118
Measles ....... .......... .......... .................... .......... .......... ......... .......... .......... ....123
Mumps ........ .......... .......... .................... .......... .......... ......... .......... .......... ....125
Orf
......... .......... .......... .................... .......... .......... ......... .......... .......... ....128
Pertussis ..... .......... .......... .................... .......... .......... ......... .......... .......... ....129
Q Fever ....... .......... .......... .................... .......... .......... ......... .......... .......... ....132
Rabies ......... .......... .......... .................... .......... .......... ......... .......... .......... ....134
Rabies, Potential Human Exposure ....... .......... .......... ......... .......... .......... ....144
Rocky Mountain Spotted Fever .............. .......... .......... ......... .......... .......... ....149
Salmonellosis (Non-Typhoidal) .............. .......... .......... ......... .......... .......... ....152
Sexually Transmitted Diseases .............. .......... .......... .. …… .......... .......... ....163
Chlamydia ... .......... .................... .......... .......... ......... .......... .......... ....163
Gonorrhea ... .......... .................... .......... .......... ......... .......... .......... ....165
Syphilis ........ .......... .................... .......... .......... ......... .......... .......... ....167
Shigellosis ... .......... .......... .................... .......... .......... ......... .......... .......... ....170
Staphylococcus aureus, Intermediate or High Level Resistance....... .......... ....177
Streptococcus pyogenes, Group A (Invasive Disease) ......... .......... .......... ....178
S. pneumoniae, Invasive ... .................... .......... .......... ......... .......... .......... ....181
Tetanus ....... .......... .......... .................... .......... .......... ......... .......... .......... ....184
Tick-borne Diseases Found in Illinois ..... .......... .......... ......... .......... .......... ....185
Toxic Shock Syndrome Due to Staphylococcus aureus ......... .......... .......... ....187
Tuberculosis .......... .......... .................... .......... .......... ......... .......... .......... ....189
Tularemia .... .......... .......... .................... .......... .......... ......... .......... .......... ....193
Typhoid Fever ........ .......... .................... .......... .......... ......... .......... .......... ....195
Varicella ...... .......... .......... .................... .......... .......... ......... .......... .......... ....197
Vibrio, Non-cholera. .......... .................... .......... .......... ......... .......... .......... ....199
Yersiniosis ... .......... .......... .................... .......... .......... ......... .......... .......... ....201
Non-foodborne, Non-waterborne Outbreaks, 2006 ...... ......... .......... .......... ....203
Reported Cases of Infectious Diseases in Illinois, 2006 ......... .......... .......... ....233
Methods ...... .......... .......... .................... .......... .......... ......... .......... .......... ....234
Reportable Communicable Diseases in Illinois
The following diseases must be reported to local health authorities in Illinois (those in bold are also nationally
notifiable, which means reportable by the state health department to the U.S. Centers for Disease Control and
Prevention):
CLASS 1(a) - The following diseases are reportable by telephone immediately (within three hours):
1.
Anthrax
5.
Smallpox
2.
Botulism, foodborne
6.
Tularemia
3.
Plague
7.
Any suspected bioterrorist threat
4.
Q-fever
or event
CLASS 1(b) -The following diseases are reportable within 24 hours of diagnosis:
1. Botulism, infant, wound, and other
12.
Measles
2. Cholera
13.
Pertussis
3. Diarrhea of the newborn
14.
Poliomyelitis
4. Diphtheria
15.
Rabies, human
5. Foodborne or waterborne illness
16.
Rabies, potential human
exposure
6. Hemolytic uremic syndrome, post-diarrheal
17.
Typhoid fever
7. Hepatitis A
18.
Typhus
8. Any unusual case or cluster of cases that may
19.
Enteric Escherichia coli infections
indicate a public health hazard
(E. coli)0157:H7 and other
9. Haemophilus influenzae, meningitis and other
enterohemorrhagic E. coli,
invasive disease
enterotoxigenic E. coli)
10. Neisseria meningitidis. Meningitis and invasive
enteropathogenic E. coli)
20.
Staphylococcus aureus infections with
disease
11. Streptococcal infections, Group A, invasive
intermediate or high level
(Including toxic shock syndrome) and sequelae
resistance to vancomycin
to group A streptococcal infections (rheumatic
fever and acute glomerulonephritis)
(Continued on attached page)
1
CLASS II-The following diseases shall be reported as soon as possible during normal business hours, but
within seven days (exceptions to the seven-day notification requirement are marked with an asterisk; see
note below.)
1.
AIDS
27.
Malaria
2.
Amebiasis
28.
Meningitis, aseptic (including arbovirus infection)
3.
Blastomycosis
29.
Mumps
4.
Brucellosis
30.
Ophthalmia neonatorum (gonococcal)*
5.
Campylobacteriosis
31.
Psittacosis
6.
Chanchroid*
32.
Reye’s syndrome
7.
Chickenpox
33.
Rocky Mountain spotted fever
8.
Chlamydia*
34.
Rubella, including congenital
9.
Cryptosporidiosis
35.
Salmonellosis (other than typhoid)
10.
Cyclosporiasis
36.
Shigellosis
11.
Ehrlichiosis, human
37.
Staphylococcus aureus infection, toxic shock
granulocytic
syndrome
12.
Ehrlichiosis, human
38.
Staphylococcus aureus infections occurring in
monocytic
infants under 28 days of age (within a health care
13.
Encephalitis
care institution or with onset after discharge)
14.
Giardiasis
39.
Streptococcal infections, group B, invasive disease,
15.
Gonorrhea*
of the newborn
16.
Hantavirus pulmonary
40.
Streptococcus pneumoniae, invasive disease
syndrome
(including antibiotic susceptibility test results)
17.
Hepatitis B
41.
Syphilis*
18.
Hepatitis C
42.
Tetanus
19.
Hepatitis, viral, other
43.
Trichinosis
20.
Histoplasmosis
44.
Tuberculosis
1
45.
Yersiniosis
21.
HIV infection
22.
Legionnaires’ disease
23.
Leprosy
24.
Leptospirosis
25.
Listeriosis
26.
Lyme disease
*Must be reported by mail or by telephone to the local health authority within five days
The occurrence of any increase in incidence of disease of unknown or unusual etiology should be
reported, with major signs and symptoms listed.
When an epidemic of a disease dangerous to the public health occurs and present rules are not
adequate for its control or prevention, more stringent requirements shall be issued by the Illinois
Department of Public Health.
2
2006 Summary of Selected Illinois Infectious Diseases
In Illinois, the communicable disease (CD) surveillance system relies on the
passive reporting of cases required by state law. Diseases are made reportable
because regular and timely information is necessary for prevention and control efforts.
The current reportable disease list mandates reporting, within specific time frames, of
certain diseases and of selected positive laboratory tests. Surveillance of notifiable
diseases provides public health workers the opportunity to ensure that ill persons
receive appropriate treatment, provide contacts with needed vaccines or other
preventive treatments, and halt outbreaks. The effectiveness of the surveillance system
relies heavily on the support of health care providers, laboratories and local health
departments in submitting information on reportable disease cases. In Illinois,
regulations require reporting by physicians, nurses, nurses aides, dentists, health care
practitioners, laboratory personnel, school personnel, long-term care personnel, day
care personnel, and university personnel. Notifiable disease data are submitted by the
Illinois Department of Public Health (the Department) on a weekly basis to be included
with national data in the Morbidity and Mortality Weekly Report (MMWR). CD rules also
include laboratory reporting. Some isolates are required to be forwarded to the
Department. For selected agents and situations, pulse field gel electrophoresis may be
performed to subtype isolates.
Three diseases – cholera, plague, and yellow fever - are internationally
quarantinable and notifiable. There are 56 diseases or conditions listed as nationally
reportable to the U.S. Centers for Disease Control and Prevention (CDC). This number
reflects certain combinations; for example, HIV and AIDS are combined under one
category as are invasive group A streptococcus (GAS) and toxic shock syndrome due to
GAS. Diseases reportable to CDC but not reportable in Illinois in 2006 include individual
cases of animal rabies, severe acute respiratory syndrome, varicella,
coccidioidomycosis, influenza associated pediatric mortality, and yellow fever. Animal
rabies testing is only performed by state laboratories, so reporting is complete through
state laboratory reporting. Other diseases in Illinois of public health importance can be
reported as cases or clusters of unusual illness. Varicella and severe acute respiratory
syndrome (SARS) reporting in Illinois was mandated in 2008. In 2006, the 10 most
frequently reported notifiable infectious diseases (excluding AIDS) in the United States
were chlamydia, giardiasis, gonorrhea, AIDS, salmonellosis, shigellosis, varicella, Lyme
disease, pertussis, syphilis and tuberculosis.
In 2006, 65 different types of infectious diseases were reportable to the Illinois
Department of Public Health (see pages 1 and 2). Many of the reportable diseases are
discussed in this annual report along with some non-reportable diseases of importance
in 2006. Case numbers for the various infectious diseases listed in this summary should
be considered minimum estimates. There are several reasons why reported numbers
are lower than the actual incidence of disease: Many individuals do not seek medical
care and thus are not diagnosed; some cases are diagnosed on a clinical basis without
confirmatory or supportive laboratory testing; and among diagnosed cases, some are
not reported. These surveillance data are used to evaluate disease distribution
trends over time rather than to identify precisely the total number of cases
occurring in the state.
3
The five most frequently reported nationally notifiable infectious diseases reported
individually (not in aggregate form) in Illinois were chlamydia, gonorrhea, HIV/AIDS,
Salmonella and mumps. Diseases with increased reporting in 2006 over the previous
five-year median included S. pneumoniae, Shigella, mumps, malaria, Lyme disease,
blastomycosis, Listeria, Rocky Mountain spotted fever, cryptosporidiosis, histoplasmosis
and pertussis.
The number of reported cases of Giardia, N. meningitidis, shiga toxin producing E.
coli, hepatitis A, varicella and Salmonella have been decreasing compared to the
previous five-year median.
Highlights of 2006 in Illinois included:
• A case of cholera acquired overseas
• A Campylobacter outbreak associated with raw milk
• A multi-state Salmonella ser. Tennessee outbreak linked to peanut butter
• A foodborne outbreak of vomiting in students linked to tortilla shells that had high
levels of calcium propionate
• Three Cryptosporidium outbreaks and one Legionella outbreak associated with
recreational water were reported
• More than 6,800 cases of chronic or resolved hepatitis C were reported.
• There were 21 cases of Lyme disease reported with exposure in Jo Daviess
County making it the Illinois county with the most reported Lyme exposures.
• A mumps outbreak originating in Iowa spread to Illinois and resulted in 798 cases.
• A case of orf was diagnosed in a sheep handler.
• The most common bat submitted for rabies testing was the big brown bat.
• One case of tetanus was reported.
• An outbreak of 74 cases of Shigella were reported in attendees of a day care in
Morgan County.
• Person to person and foodborne norovirus outbreaks were reported and affected
at least 5,729 Illinois residents.
Studies mentioned in the text of this report will be referred to in the selected
readings sections. The reporting of infectious diseases by physicians, laboratory and
hospital personnel, and local health departments is much appreciated. Without the
support of the local health departments in following up on disease reports, it would not
be possible to publish this annual report. The Department hopes you find this information
useful and welcomes any suggestions on additional information that would be of use to
you.
Useful Contact/Surveillance Information
Illinois Department of Public Health Web site www.idph.state.il.us
To report cases: Contact your local health department.
To refer isolates to the Illinois Department of Public Health lab ship to one of these
locations:
Public Health Laboratory, 825 N. Rutledge St., Springfield, IL 62761
Public Health Laboratory, 1155 S. Oakland Ave., P.O. Box 2797, Carbondale, IL 62901
4
Public Health Laboratory, 2121 W. Taylor St., Chicago, IL 60612
5
Illinois Counties
6
Acquired Immune Deficiency Syndrome/Human Immunodeficiency Virus
Background
Since the first cases were reported in the summer of 1981, acquired immune
deficiency syndrome (AIDS) has become one of the major health problems to emerge in
the past 25 years. In 1984, the human immunodeficiency virus (HIV) was identified as
the causative agent of AIDS. The disease is spread by the exchange of blood, semen or
vaginal secretions between individuals. The most common routes of transmission are 1)
having sex (anal, oral or vaginal) with an infected person, 2) sharing drug injection
equipment with an infected person (including insulin or steroid needles), and 3) from
mother to infant (perinatal) before or at the time of birth or through breastfeeding.
Within weeks to months after infection with HIV, some individuals develop a flulike illness. After this initial illness, individuals with HIV may remain free of clinical signs
for months to years. Since the progression of HIV to AIDS is as high as 50 percent
among untreated infected adults monitored for 10 years, assessing the impact of the
epidemic in Illinois has relied mainly on the reporting of cases that met the AIDS
definition.
Clinical indicators of HIV infection may include lymphadenopathy, chronic
diarrhea, weight loss, fever and fatigue followed by opportunistic infections. HIV may
progress to AIDS, which includes a variety of late-term clinical manifestations including
low T-cell counts. Opportunistic infections associated with AIDS include Pneumocystis
carinii pneumonia, chronic cryptosporidiosis, central nervous system toxoplasmosis,
candidiasis, disseminated cryptococcosis, tuberculosis, disseminated atypical
mycobacteriosis and some forms of cytomegalovirus infection. Some cancers also may
be associated with AIDS (e.g., Kaposi sarcoma, primary B-cell lymphoma of the brain,
invasive cervical cancer and non-Hodgkin’s lymphoma).
Increased knowledge of the disease and improved diagnostic and treatment
methods have led to significant advances in the clinical management of HIV and resulted
in a delay in the progression from HIV to AIDS and a reduction in AIDS morbidity and
mortality. A number of antiretroviral agents are available for treatment of HIV/AIDS, and
combination therapies have been shown to prolong and improve the quality of life for
those who are infected.
Case definition
In the state of Illinois, AIDS has always been reported by the patient’s name, while
HIV reporting was without patient identifiers until July 1, 1999. For HIV reporting, this
meant that individuals with multiple positive test results for HIV were counted as new HIV
cases each time they tested positive. Case reporting by name for HIV began on January
1, 2006.
7
Over the years, there have been three case definitions for AIDS, which should be
taken into account when reviewing trends over time. The changes can be referred to as
pre-1987, the 1987 revision and the 1993 revision. To review the case definitions and
how they have changed over time, the following editions of the Morbidity and Mortality
Weekly Reports (MMWR) should be reviewed:
1)
2)
3)
4)
Review of the CDC surveillance case definition for acquired immunodeficiency
syndrome. MMWR 1987;36 (Suppl:)1-15s.
1993 revised classification system for HIV infection and expanded surveillance
case definition for AIDS among adolescents and adults. MMWR 1992;41(RR17):1-19.
1994 revised system for human immunodeficiency virus infection in children
younger than 13 years of age. MMWR 1994;43(RR-12): 1-19.
Case definitions for infectious conditions under public health surveillance.
MMWR 1997;46(RR-10): 5-6.
Additional changes, including a revised case definition for HIV infection in adults
and children, became effective January 1, 2000. For information about this latest
revision, see “Guidelines for national human immunodeficiency virus case surveillance,
including monitoring for human immunodeficiency virus infection and acquired
immunodeficiency syndrome; MMWR 1999; 48 (No. RR-13)”.
Descriptive epidemiology
• Number of AIDS cases reported in calendar year 2006 – 1,254. The number of
reported AIDS cases declined from the 1,321 cases reported in 2005. The number of
reported HIV cases was 1,876, a decline over the 3,216 reported in 2005.
• Risk factors – Overall, 41 percent of AIDS cases were in MSMs, followed by 16
percent in heterosexuals (Figure 1). For HIV cases, 43 percent were in MSMs and 13
percent in IDUs (Figure 2).
• The majority of reported AIDS cases in 2006 were in males (964 cases or 77
percent). For all cases reported among males, men who have sex with men (MSM)
accounted for the largest number of AIDS cases (500 cases or 52 percent), followed
by injection drug use (IDU) with 117 cases or 12 percent (Figure 3).
• Reported cases of AIDS among females accounted for 290 cases or 23 percent of
the total AIDS cases reported in 2006. Among females, heterosexual contact
accounted for 132 cases or 46 percent of the total, with IDU accounting for 64 cases
or 22 percent (Figure 4).
• The majority of reported HIV cases in 2006 were males (1,439 or 77 percent). For all
cases among males, MSM accounted for the largest number of HIV cases (807, 57
percent), followed by IDU (89 cases, 6 percent) (Figure 5).
• Reported cases of HIV among females accounted for 290 or 23 percent of HIV cases
reported in 2006. Among females, heterosexual contact accounted for 174 of 40
percent of the total, with IDU accounting for 65 or 15 percent of the total (Figure 6).
• Age – The age distribution of HIV cases in shown in Figure 7.
• Race/ethnicity - African American non-Hispanics accounted for 55 percent of the
AIDS cases reported in 2006. White non-Hispanics made up 26 percent of reported
AIDS cases. For reported HIV cases, African American non-Hispanics comprised 52
8
•
percent of cases, white non-Hispanics were 33 percent and Hispanics were 12
percent.
In 2006, Cook County and the collar counties (Dupage, Kane, Lake, McHenry and
Will) comprised 81 percent of the total AIDS cases. Cook County and the collar
counties comprised 80 percent of the total HIV cases.
Summary
The number of cases of AIDS reported in Illinois was 1,254 and the number of
HIV cases was 1,876. Most reported AIDS cases were in males. The most common risk
factor for transmission for AIDS in males was MSM. Heterosexual contact was the most
common risk factor for females for AIDS, followed by IDU. This year was the first for
named HIV reporting.
Figure 1. Reported AIDS Cases in Illinois by Mode of Transmission, 2006
25%
MSM
Heterosexual
41%
IDU
4%
MSM/IDU
14%
Undetermined/other
16%
Figure 2. Reported HIV Cases in Illinois by Mode of Transmission, 2006
MSM
34%
Heterosexual
43%
IDU
MSM/IDU
2%
8%
Undetermined/other
13%
9
Figure 3. Reported AIDS Cases in Illinois Males by Mode of Transmission,
2006
MSM
23%
Heterosexual
IDU
52%
6%
MSM/IDU
12%
Undetermined/other
7%
Figure 4. Reported AIDS Cases in Illinois in Females by Mode of
Transmission, 2006
31%
Heterosexual
47%
IDU
Undetermined/other
22%
Figure 5. Reported HIV Cases in Illinois Males by Mode of Transmission,
2006
MSM
30%
Heterosexual
IDU
57%
2%
MSM/IDU
6%
Undetermined/other
5%
Figure 6. Reported HIV Cases in Illinois in Females by Mode of
Transmission, 2006
Heterosexual
40%
45%
IDU
Undetermined/other
15%
10
Number of cases
Figure 7. Age Distribution of HIV Cases Reported in Illinois, 2006
400
300
200
100
0
0-12
13-19
20-24
25-29
30-34
Age in years
11
35-39
40-44
45-49
>49
Amebiasis
Background
Entamoeba histolytica is a protozoan parasite that exists in two forms: the cyst
and the trophozoite. It is an important health risk to travelers to the Indian subcontinent,
southern and western Africa, the Far East, and areas of South and Central America.
Intestinal disease can range from mild diarrhea to dysentery with fever, chills, weight loss
and bloody or mucoid diarrhea. Extraintestinal amebiasis also can occur. Persons can
develop amebic liver abscess, which is more common in males than females. This may
occur within two to four weeks of infection and include fever, cough and dull aching
abdominal pain. Some persons are asymptomatic. Humans are the reservoir for
Entamoeba histolytica. Infection occurs when a person ingests fecally contaminated food
or water that contains the cyst or through oral-anal contact. The incubation period ranges
from two to four weeks. In the United States, amebiasis is most commonly seen in
immigrants and travelers to foreign countries.
While examination of stool for ova and parasites often is done, these tests cannot
differentiate E. histolytica from nonpathogenic species like E. dispar and E. moshkovskii.
There are now polymerase chain reaction (PCR) and antigen detection tests which can
be used for differentiation.
Case definition
The CDC case definition used by the Department for a confirmed intestinal
amebiasis case is as follows: a clinically compatible illness that is laboratory confirmed
by demonstration of cysts or trophozoites of E. histolytica in stool, or demonstration of
trophozoites in tissue biopsy or in ulcer scraping by culture or histopathology. The
definition for a case of extraintestinal amebiasis is a parasitologically confirmed infection
of extraintestinal tissue; or, among symptomatic persons with clinical and/or radiographic
findings consistent with extraintestinal infection, demonstration of specific antibody
against E. histolytica as measured by indirect hemagglutination or enzyme-linked
immunosorbent assay (ELISA).
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 75 (five-year median = 75). All cases
were confirmed. From 2001 to 2006, the number of cases reported per year ranged
from 43 to 130 (Figure 8).
• Age - Cases ranged from 12 years to 82 years of age (mean= 34 years) (Figure 9).
• Gender - Males accounted for 57 percent of cases.
• Race/ethnicity - Forty percent of cases were white, 28 percent were African
American, with 32 percent reporting some other racial identity; 29 percent of 59 cases
for whom a response is known identified themselves as Hispanic, a significantly
higher proportion than in the total Illinois population (12 percent).
• Seasonal variation – There was an increase in cases in February (Figure 10).
• Geographic location – Fifty-five of 74 (74 percent) of cases lived in Cook County.
• Clinical outcome – Five of 24 cases with information available were admitted to the
hospital, and none were known to be fatal.
12
Summary
The number of cases in 2006 was higher than the five-year median, Amebiasis
was significantly more common in those reporting Hispanic ethnicity.
Number of cases
Figure 8 . Amebiasis Cases in Illinois, 2001-2006
100
80
60
40
20
0
89
86
75
65
75
49
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 9. Age Distribution of Amebiasis Cases in Illinois, 2006
20
15
10
5
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Age in years
Number of cases
Figure 10. Amebiasis Cases in Illinois by Month, 2006
10
8
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
13
Aug
Sep
Oct
Nov
Dec
Blastomycosis
Background
Blastomyces dermatitidis is a dimorphic fungus found in both Canada and the
United States. Blastomycosis is a zoonotic disease endemic in the midwestern United
States. Occasionally, outbreaks occur in areas outside the endemic areas. The ideal
area for the mycelial form of the organism is soil of warm, moist, wooded areas rich in
organic debris. Recreational activities along waterways are considered to be a major risk
factor for infection. Transmission is usually through inhalation of spore-laden dust.
Blastomycosis most commonly presents as a subacute pulmonary disease but can range
from asymptomatic to disseminated disease. For symptomatic infections, the incubation
period ranges from 30 to 45 days.
Case definition
The case definition for confirmed blastomycosis in Illinois is culture confirmation of
Blastomyces dermatitidis. If the diagnosis was based on a needle aspirate or other
diagnostic specimen with demonstration of organism resembling Blastomyces or a
presumptive Blastomycosis culture, it is considered a probable case.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 119 (previous five-year median= 89).
All but five cases were confirmed. From 2001 to 2006, cases per year ranged from 47
to 119 (Figure 11). The 2006 incidence rate was 0.95 per 100,000 population in
Illinois.
• Age - The mean age was 47 years (range 15 to 85) (Figure 12).
• Gender - Seventy percent were male and males were overrepresented in cases as
compared to the Illinois population.
• Race/ethnicity – Forty-eight percent of the cases were white, 44 percent were African
American, and 4 percent were other races; 24 percent were Hispanic.
• Geographic distribution – Sixty percent of the cases had residential addresses in
Cook or Lake counties.
• Seasonal – There did not appear to be a seasonal pattern to the cases.
• Diagnosis – Of the 119 cases reported, 113 were culture positive. Six were not
culture confirmed. The most common specimen source for culture was bronchial fluid
(52), skin (16), lung tissue (15) and sputum (12).
• Reporting – Sixty-eight percent of reports were from infection control professionals
and 30 percent from laboratory staff.
• Treatment – Seventy-eight percent of cases were hospitalized; six cases were fatal
with a mean age of 57 years.
Summary
A higher number of blastomycosis cases were reported in 2006 (119 cases) as
compared to the five-year median of 89. This is the highest number of cases reported
since at least 1996. Blastomycosis cases occur predominantly in adults. Many cases had
symptoms of respiratory involvement, including cough, dyspnea or hemoptysis. Ninetyfive percent of reported cases were confirmed by culture. Among reported cases, 60
percent of cases reported living in Cook or Lake counties.
14
Number of cases
Figure 11. Blastomycosis Cases in Illinois, 2001-2006
150
100
119
104
91
89
87
47
50
0
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 12 . Blastom ycosis Cases by Age in Illinois, 2006
40
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
Age in years
15
30-39yr
40-49 yr
50-59 yr
>60 yr
Botulism
Background
There are three forms of botulism: foodborne, wound, and intestinal (adult and
infant). Botulism toxins cause neuromuscular blockage, which results in flaccid paralysis.
All forms of botulism produce the same distinct clinical syndrome, which includes
symmetrical cranial nerve palsies followed by descending flaccid symmetrical paralysis
that can progress to constipation, respiratory failure, and death. Other symptoms of
botulism include diplopia, blurred vision, abnormal body temperature, and ptosis. As
botulism progresses, the patient retains intellectual function. The absence of cranial
nerve palsies (blurry vision, diplopia, ptosis, facial paralysis, dysphagia, severe dry
mouth) rules out a diagnosis of botulism. Differential diagnoses include myasthenia
gravis and Guillain-Barré syndrome. These can be differentiated using electromyography
(EMG), the pattern of paralysis and reaction to Tensilon.
Foodborne botulism is caused by a neurotoxin produced by Clostridium botulinum
and results from ingestion of preformed toxin present in contaminated food. C. botulinum
is found in soil and aquatic sediments. Seven toxins (A-G) can be produced by C.
botulinum. C. baratii and C. butyricum also can produce some botulinum toxins. Human
cases are caused mainly by toxin types A, B, E and, rarely, F. C. botulinum can form a
spore that survives cooking and food processing measures. Spore germination can
occur during anaerobic conditions, consisting of nonacidic pH and low salt and sugar
content. Botulism toxins are inactivated by heating. Foodborne botulism can occur in
home canned foods and traditional native Alaskan dishes. A large outbreak of foodborne
botulism occurred in Thailand due to consumption of bamboo shoots. Forty-two of 209
patients required mechanical ventilation.
Treatment for foodborne botulism is prompt administration of polyvalent equine
source antitoxin which can decrease progression of paralysis but not reverse existing
paralysis. Equine botulinum antitoxin for types A, B and E can prevent progression of
neurologic disease if administered early in the course of illness.
The most common form of intestinal botulism and of botulism in general is infant
botulism. It occurs in infants younger than one year of age. Infant botulism results when
swallowed spores germinate and temporarily colonize the large intestine. It is believed to
occur because competing organisms are not yet present in the digestive tract. Honey
consumption has been linked to some infant botulism cases but probably only accounts
for about 20 percent of infections. Botulism in infants younger than 12 months of age
should be suspected when constipation, lethargy, poor feeding, weak cry, bulbar palsies,
and failure to thrive are present. Diagnosis of infant botulism involves detection of
botulinum toxin in stool or serum by using a mouse neutralization assay or the isolation
of toxigenic C. botulinum in the feces by enrichment culture techniques. Adult intestinal
botulism is rare and occurs mainly in patients with an anatomical or functional bowel
abnormality or those patients using antimicrobials, which decreases the normal flora to
compete with Clostridium species.
Wound botulism occurs after the causative organism contaminates a wound that
is anaerobic. Wound botulism has increased in recent years due to an increase in
injection drug users, especially those who use heroin. Iatrogenic botulism is caused by
injection of botulinum toxin for cosmetic or therapeutic purposes. The doses used for
cosmetic treatment are too low to cause systemic disease.
16
If botulism is suspected, contact your local health department immediately. This
will allow for rapid investigation to identify the source. If the source was a commercial
product, it can be removed promptly from the market.
Twenty cases of foodborne botulism were reported in 2006 to CDC. There were
also 97 cases of infant botulism and 48 cases of other types of botulism.
Case definition
Botulism, infant
Clinical illness may include poor feeding, constipation, failure to thrive, and
respiratory failure. The case definition for infant botulism is a clinically compatible case
that is laboratory confirmed, occurring in a child younger than 1 year of age. Laboratory
confirmation is isolation of C. botulinum from stool or detection of botulinum toxin in stool
or serum.
Botulism, foodborne
Clinical illness includes diplopia, blurred vision and bulbar weakness. Symmetric
paralysis may progress quickly. Laboratory confirmation consists of detection of
botulinum toxin in stool, serum or patient ‘s food or isolation of C. botulinum from stool. A
probable case is a clinically compatible case with an epidemiologic link (ingestion of
home-canned food within the previous 48 hours). A confirmed case is a clinically
compatible case that is laboratory confirmed or that occurs among persons who ate the
same food as persons who have laboratory-confirmed botulism.
Botulism, wound
Common symptoms include diplopia, blurred vision and bulbar weakness as well
as symmetric paralysis. Laboratory confirmation is by detection of botulinum toxin in
serum or isolation of C. botulinum from wound. A confirmed case is a clinically
compatible illness that is laboratory confirmed in a patient who has no suspected
exposure to contaminated food and who has a history of a fresh, contaminated wound
during the two weeks before symptom onset.
Descriptive epidemiology
• There was one case of foodborne and one infant botulism case reported in 2006.
• Foodborne botulism case. This case was a 70-year-old female from Cook County
with botulism toxin type B. The serum test was positive, and the stool test was
negative. The person became ill while in Poland and had consumed food items in
Poland. Symptoms included blurred and double vision, constipation, vomiting, and
weakness.
• Infant botulism case – Infant developed droopy head, ptosis, difficulty breathing, poor
feeding and constipation. Mechanical ventilation was required. CDC performed
testing but results are unavailable. Infant was treated with BabyBIG ®. Infant was
breast fed and drank some bottled water.
Suggested readings
Kongsaengdao, S. et al. An outbreak of botulism in Thailand: Clinical
manifestations and management of severe respiratory failure. Clin Inf Dis 2006; 43:124756.
17
Brucellosis
Background
Brucellosis is a systemic bacterial infection caused by Brucella species that can
cause intermittent or continuous fever and headache, lower back pain, sweating and
arthralgia. Chronic disease can result in abscesses in the liver, spleen, brain, bone or
heart valves. The incubation period varies from two to 10 weeks (range of a few days to
six months). Symptoms can last from days to years. Brucella species considered of
importance in human disease include B. abortus (cattle are the primary reservoir), B.
melitensis (sheep and goats are the primary reservoir) and B. suis (swine are the primary
reservoir). B. melitensis has not been identified in animals in the United States since
1999. Dogs are reservoirs of B. canis but are not considered to be an important public
health concern in the United States. Transmission is by contact with animal tissues, such
as blood, urine, vaginal discharges, aborted fetuses and placentas and by ingestion of
raw milk or other dairy products. Investigation of Brucella cases could reveal foci of
infection in United States livestock that should be investigated and eliminated. The
disease is most common in residents or travelers to the Mediterranean, Middle East,
Mexico, and Central and South America. The large majority of human Brucella cases are
thought to be due to travel outside the country and consumption of contaminated
products from those countries. Brucella is also a Class A bioterrorism agent. Biosafety
level 3 is recommended for laboratory manipulation of isolates. Brucella is the most
commonly recognized cause of laboratory transmitted infection; about 2 percent of all
Brucella cases may be laboratory acquired. The infecting dose for humans is low; the
organism can enter the body in many ways including through the respiratory tract,
conjunctivae, through the gastrointestinal tract or through abraded skin. Laboratory
infections have been acquired from sniffing culture plates and exposure to spills. Most
cases of laboratory-acquired infection are from the more virulent B. melitensis species.
Unidentified specimens are often handled on an open bench, which may result in
exposures. When Brucella is suspected, the clinician or forwarding laboratory should
note on the laboratory submission form, “Suspect or rule out brucellosis” so appropriate
precautions can be taken.
Cross reactions and false positive results can result when enzyme immunoassay
tests developed for Brucella endemic areas and not approved by FDA and CLIA are
used for diagnosis in the United States. Screening tests should be used in situations
where there was the risk of Brucella exposure and the illness is clinically compatible.
Positive screening tests should be confirmed by culture or agglutination testing before
initiating prolonged antibiotic therapy or public health investigations of suspected
sources. Agglutination tests detect IgM, IgG and IgA antibodies. Cross reactivity to other
gram negative organisms including E. coli O157:H7, F. tularensis, Salmonella and
Yersinia can occur when using enzyme immunoassay tests.
In some developing countries the incidence of brucellosis may be as high as 200
per 100,000, but the disease is rare in the United States. In the United States in 2006,
121 human brucellosis cases were reported to CDC. Most were in international travelers
or immigrants. Illinois was third in the nation in the number of Brucella cases reported.
18
Case definition
Illinois uses the CDC case definition for brucellosis. The case definition for a
confirmed case of brucellosis is a clinically compatible illness with one of the following
laboratory findings: isolation of Brucella from a clinical specimen, a four-fold or greater
rise in Brucella agglutination titer between acute and convalescent phase serum
specimens obtained greater than or equal to two weeks apart and studied at the same
laboratory, or demonstration of Brucella species in a clinical specimen by
immunofluorescence. A probable case is defined as a clinically compatible case that is
epidemiologically linked to a confirmed case or that has supportive serology (i.e.,
Brucella agglutination titer of at least 160 in one or more serum specimens obtained after
symptom onset).
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – Eight (seven were confirmed, and one
was probable) (See Figure 13). The five-year median was seven cases.
• Age – The mean age was 28 years (range 2 to 19 years).
• Gender - Three cases were male, and five were female.
• Race/ethnicity – Race was known for six cases and five were white and one was
other race; seven cases were Hispanic.
• Geographic distribution by residence – There were five cases in Cook County, and
one case each in Boone, Kane and Will counties.
• Case investigations o Cases one and two – Two children from the same family contracted B.
melitensis. The two children had been in Mexico.
o Case three – The case had B. melitensis biovar 1 and ate unpasturized goat
cheese in Mexico.
o Case four – The case had B. melitensis biovar 3 and reported no travel and no
consumption of unpasteurized dairy products.
o Case five – The case had B. melitensis biovar 3 and consumed unpasteurized
dairy products in Spain.
o Case six – The case consumed unpasteurized goat cheese from Mexico
brought into this country by the father. The species was unknown.
o Case seven – This case with B. melitensis reported no recent travel but had
eaten unpasteurized dairy products in Mexico many years previously. The
patient had backache and arthralgia. The isolate from this individual resulted in
Brucella infection in two out-of-state laboratory workers.
o Case eight –This case had a high titer to B. abortus, and risk factors were
unknown.
• Diagnosis – Cultures were Brucella positive for seven cases. Results for speciation
were identified for seven isolates: B. melitensis, unknown biovar (two), B. melitensis
biovar 1 (one) and B. melitensis biovar 3 (four). One probable case had a high titer to
B. abortus.
• Clinical syndrome – Three cases were hospitalized. No deaths were reported.
• Epidemiology – Four persons of seven with an epidemiologic history reported travel
overseas. Six of these individuals remembered consuming unpasteurized dairy
products from other countries. Symptoms reported by cases included fever (seven
cases), weight loss (seven cases), night sweats (five cases) and bone involvement
19
(three cases).
Summary
In Illinois, brucellosis is an uncommon disease and tends to occur primarily in
individuals who have recently traveled to foreign countries and consumed unpasteurized
dairy products or who have consumed unpasteurized dairy products imported from
foreign countries. In 2006, there were eight brucellosis cases reported in Illinois
residents, which was the third highest number among the states reporting cases
(California and Texas reported higher numbers of cases).
Suggested readings
Anon. Laboratory-acquired brucellosis – Indiana and Minnesota, 2006. MMWR
2008; 57(2): 39-42.
Prayle, A., et.al. Public health consequences of a false-positive laboratory test
result for Brucella – Florida, Georgia and Michigan, 2005. MMWR 2008;57(22):603-6.
Number of cases
Figure 13. Brucellosis Cases in Illinois, 2001-2006
13
15
9
10
5
8
7
4
0
0
2001
2002
2003
2004
Year
20
2005
2006
Campylobacteriosis
Background
Campylobacteriosis is a zoonotic bacterial enteric disease caused primarily by
Campylobacter jejuni and occasionally by Campylobacter coli. Campylobacter organisms
are motile, gram-negative bacilli with a curved shape. The infectious dose is large. The
incubation period is two to five days. Symptoms may last up to 10 days and include
diarrhea, abdominal pain and fever; however, many infections are asymptomatic.
Sequelae may include reactive arthritis, febrile convulsions, a typhoid-like syndrome,
Guillain-Barré syndrome or meningitis. C. jejuni infection is the most frequently identified
infection preceding Guillain-Barre syndrome. Reactive arthritis can occur seven to 10
days after diarrheal illness. Excretion of the organism can occur for two to seven weeks.
Approximately 1 percent of the population acquires Campylobacter each year in
the United States. Among all 10 diseases under active surveillance in the federal
FoodNet sites (Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS,
Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica),
infection with Campylobacter comprised 5,712 of 17,252 (33 percent) of all of those
reported in 2006. The preliminary overall incidence for this infection from the 10 FoodNet
sites was 12.7 per 100,000 in 2006. The 2010 national health objective is for less than
12 cases per 100,000. Campylobacter decreased 30 percent from baseline data from the
FoodNet sites. In a study of nationally reported cases in six states in 2002, the median
interval from symptoms to interview of patient was 18 days.
The reservoir for Campylobacter is animals, most commonly poultry and cattle.
The most important mode of transmission to humans is the consumption and handling of
raw poultry products. Campylobacter is found in approximately 80 percent of retail
chicken meat. Campylobacter is also a cause of traveler’s diarrhea.
Prevention of campylobacteriosis includes cooking meat thoroughly, avoiding
cross-contamination between foods and handwashing after animal handling.
Case definition
The case definition for a confirmed case of campylobacteriosis in Illinois is a
clinically compatible illness with isolation of Campylobacter from any clinical specimen. A
probable case is a clinically compatible illness that is epidemiologically linked to a
confirmed case.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 1,294 (previous five-year median =
1,265); incidence rate of 10 per 100,000 (Figure 14). All but three were confirmed
cases.
• Gender – Fifty-six percent of cases were male.
• Age - Mean age of reported cases was 47; highest incidence rate occurred in those
younger than 5 years of age and those 50 to 59 years old (Figure 15).
• Race/ethnicity - The majority of cases (88 percent) were in whites, with 4 percent in
African Americans, 2 percent in Asians and 5 percent in other races. Those indicating
Hispanic ethnicity accounted for 12 percent of the cases. There was a significantly
higher proportion of whites with campylobacteriosis and a lower proportion of African
Americans with the disease than in the total Illinois population.
21
•
•
•
•
•
•
•
Seasonal variation - Campylobacteriosis was reported more often in the warmer
months of the year in Illinois (May through October) (Figure 16).
Geographic distribution – The five counties reporting the most cases were Cook
(452), Lake (127), DuPage (107), Will (62) and Kane (54).
Clinical – Ninety-eight percent of 657 reported cases reported diarrhea. Thirty-five
percent of 556 cases reported vomiting. Twenty-seven percent of 956 reported cases
with hospitalization information were hospitalized. One case was reported to have
died as a result of this illness.
Campylobacter species identified – The species of Campylobacter was available for
427 cases. The species was identified as jejuni (394 cases), coli (18), lari (13), rectus
(one) and fetus (one).
Risk factors
o Travel – Fifty-six of 417 (13 percent) reported travel to another country. Fortythree of 431 (10 percent) reported travel to another state.
o Animal contact – Information on animal contact was available for 409 cases.
Of these, 257 (63 percent) reported animal contact. Contact with dogs was
reported for 183 individuals and contact with ill dogs was reported for 23 dog
owners. Eleven specifically reported contact with ill puppies. Three individuals
reported contact with multiple dogs in kennels or humane societies. Of the 409
cases with animal contact information, 104 reported contact with cats. Seven
cases reported contact with cats with diarrhea with four of these seven cases
reporting contact with kittens with diarrhea.
Reporting – Fifty percent of cases were reported by infection control professionals
and 37 percent of cases by laboratory staff.
Outbreaks – One outbreak was reported, see foodborne outbreak section for details.
Summary
The incidence of the disease in 2006 was 10 per 100,000. This rate was below
the 2010 national objectives of 12 per 100,000. Campylobacter infections occur more
commonly from May through October. The incidence was highest in 1- to 4-year-olds
and 50- to -59-year-olds. Whites are more likely to be reported with campylobacteriosis
than other races.
Suggested readings
Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states.
Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from
http://www.cdc.gov/EID/content/14/2/311
22
Number of cases
Figure 14. Campylobacteriosis Cases in Illinois, 2001-2006
1500
1405
1376
1400
1300
1294
1265
1235
1204
1200
1100
2001
2002
2003
2004
2005
2006
Year
Incidence per
100,000
Figure 15 . Incidence of Campylobacteriosis Cases in Illinois by Age,
2006
20
15
10
5
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Year
Number of cases
Figure 16. Campylobacteriosis Cases in Illinois by Month, 2006
250
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
23
Aug
Sep
Oct
Nov
Dec
Central Nervous System Infections
General
Both aseptic meningitis and acute encephalitis were reportable in Illinois in 2006.
The purpose of this reporting is to identify arboviral infections. Control measures for
arboviruses are possible and include public education and mosquito control activities.
Aseptic meningitis is usually a self-limiting illness characterized by sudden onset
of fever, headache and stiff neck. A rash may be present along with vomiting,
photophobia and nausea. In the United States, enteroviruses cause most cases with
known etiology. Some arboviral infections may present as aseptic meningitis.
Acute infectious and post-infectious encephalitis were reportable in Illinois in
2006. Infections are characterized by headache, high fever, meningeal signs, stupor,
disorientation, coma, tremors, convulsions or paralysis.
Aseptic meningitis and encephalitis are combined into two sections: unknown
etiology and known etiology. Arbovirus infections were put in a third section. Cases of
each type of CNS infection are shown in Table 1 and the number of reported CNS
infections by year is shown in Figure 17.
Table 1. Number of Reported CNS Infections Reported in Illinois, 2006
Type of CNS Infection
2006
Aseptic meningitis, unknown
834
etiology
Aseptic meningitis, known
111
virus, not arboviral
Encephalitis, acute, known
26
virus, not arboviral
Encephalitis, acute, unknown
101
etiology
WNV
215
California encephalitis
0
SLE
0
Dengue
6
TOTAL
1,293
# reported
cases
Figure 17. Reported Non-bacterial CNS Infections by Year in Illinois,
2001-2006
3000
2000
1000
0
1858
2147
2001
2002
1528
1480
1632
1293
2003
2004
2005
2006
Year
24
Aseptic Meningitis or Encephalitis of Unknown Etiology
Background
Both aseptic meningitis and encephalitis are reportable in Illinois. One of the
purposes of this reporting is to identify arboviruses. Although virus isolation and serologic
testing for arboviruses (during the appropriate season) is offered for free to health care
providers for all persons in the state with aseptic meningitis or encephalitis, the etiology
of many cases of aseptic meningitis and encephalitis remains unknown.
Case definition
The case definition for aseptic meningitis in Illinois is a clinically compatible illness
diagnosed by a physician as aseptic meningitis with elevated white blood cells in the
CSF but no laboratory evidence of bacterial or fungal meningitis. For aseptic meningitis
of unknown etiology, no virus could be isolated from the person and testing for
arboviruses was negative or testing was not done.
The case definition for primary encephalitis is a clinically compatible illness
diagnosed by a physician as primary encephalitis. For encephalitis of unknown etiology,
no virus could be isolated from the patient and there were no positive tests for
arboviruses.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 935 (834 meningitis cases and 101
encephalitis cases).
• Age – The annual incidence rate was highest in those younger than 1 year of age (93
per 100,000) (Figure 18). In all other age groups, the incidence rate was below 9 per
100,000. The mean age of reported cases was 23.
• Gender – Fifty-one percent were male.
• Race/ethnicity – The cases were white (73 percent), African American (18 percent)
and other races (8 percent); 24 percent reported Hispanic ethnicity.
• Seasonal variation – Cases were most common from July through October (Figure
19); Of the total cases, 578 had onsets between May 15 and October 31 (357 cases
had onsets outside of this time frame).
• Geographic distribution – The highest number of cases were reported from Cook
(407), DuPage (108), Lake (69), Will (62) and Kane (48).
Summary
Cases of aseptic meningitis and acute encephalitis with no known cause occur
with greater frequency in the summer months and in those younger than 1 year of age.
However, reporting of these infections is required from May 15 through October 31
resulting in an increase in reporting during these months of the year.
25
Incidence per
100,000
Figure 18. Incidence of Aseptic Meningitis and Encephalitis, Unknown
Etiology in Illinois by Age, 2006
100
50
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-59 yr
> 59 yr
Age groups
Number of cases
Figure 19. Aseptic Meningitis and Encephalitis, Unknown Etiology by
Month, 2006
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Year
26
Aug
Sep
Oct
Nov
Dec
Aseptic Meningitis or Encephalitis of Known Etiology, Excluding Arboviruses
Background
Both aseptic meningitis and encephalitis were reportable in Illinois in 2006. One of
the purposes of this reporting was to identify arboviruses. Virus isolation is offered to all
health care providers of persons in the state with aseptic meningitis or encephalitis, and
this helps to identify the etiology of some cases.
Encephalitis can be caused by infectious, postinfectious and postimmunization
causes. Pathogens causing infectious encephalitis include herpes simplex virus,
arboviruses, lymphocytic choriomeningitis, mumps, cytomegalovirus, Epstein-Barr virus,
human herpesvirus 6 and enteroviruses. Herpes simplex is a common cause of acute
encephalitis that occurs most frequently in children and the elderly. Many encephalitis
cases in the United States and Illinois are not identified as to the etiology.
Aseptic meningitis is an inflammation of the meninges that cover the brain and
spinal cord. It is often caused by a virus, frequently an enterovirus. Enterovirus activity
usually peaks during summer and early fall. Enterovirus illness is usually mild and only a
small proportion result in aseptic meningitis. Children are at greater risk of severe
manifestations with enteroviruses. Adults with enterovirus are more likely to experience
upper respiratory symptoms. Enterovirus is shed in saliva and feces of infected persons.
Persons should wash their hands thoroughly after using the bathroom and avoid sharing
drinks and utensils during an outbreak.
Enterovirus infections are not nationally notifiable. Seroypes of human
enteroviruses are classified into echoviruses, coxsackieviruses and polioviruses. From
1970 through 2005, the five enteroviruses most commonly reported to CDC through the
national voluntary enterovirus typing included echoviruses 9,11,30 and 6 and coxsackie
B5. Children younger than 1 year of age accounted for 44 percent of reports. Seventyeight percent of reports were reported from June through October. Cerebrospinal fluid
was the most common specimen type followed by respiratory and fecal submissions.
They are reportable in Illinois as a part of the state aseptic meningitis reporting.
Case definition
The case definition for aseptic meningitis in Illinois is a clinically compatible illness
diagnosed by a physician as aseptic meningitis with elevated white blood cells (greater
than 4 cells) in the CSF but no laboratory evidence of bacterial or fungal meningitis. For
aseptic meningitis of known etiology, a virus could be isolated from the person and no
arbovirus testing was positive in specimens from the person.
The case definition for primary encephalitis is a clinically compatible illness
diagnosed by a physician as primary encephalitis. For encephalitis of known etiology, a
virus could be isolated from the patient and there was no positive test for arboviruses.
Descriptive epidemiology
• Number of cases – The number of cases reported was 137 cases (111
meningitis and 26 encephalitis).
• Age – The mean age was 29 years.
• Gender – Fifty-three percent of cases were male.
• Race/ethnicity – Seventy-four percent were white, 19 percent African
American and 7 percent other races; 15 percent were Hispanic.
27
•
Seasonal variation - Aseptic meningitis or encephalitis of known etiology,
excluding arboviruses were most commonly reported from August through
September (Figure 20). Of the 137 cases, 89 cases (65 percent) had onsets
during arbovirus season from May 15 through October 31.
• Geographic – The three counties reporting the highest number of cases were
Cook (52), Winnebago (11) and Sangamon (10).
• Diagnosis – Viruses identified as the etiologic agent were enterovirus, not
further specified (64), herpes simplex (31), echovirus 6 (four), coxsackie B5
(three), echovirus, not further specified (three), echovirus 9 (two), coxsackie
B3 (one) and coxsackie B4 (one). Unknown viruses were specified in 15
cases. Other types of organisms reported as etiologic agents included
Cryptococcus (13).
Summary
In 358 of 1,293 (28 percent) of encephalitis and aseptic meningitis cases, an
etiologic agent (including arboviruses) was identified as the cause of illness. Herpes
simplex, coxsackie B5 and echovirus 6 were the most common specific viruses identified
as the causative agents for aseptic meningitis and encephalitis cases. Arbovirus cases
are described in a later section.
Number of cases
Figure 20. Aseptic Meningitis and Encephalitis, Non-Arbovirus, Known
Etiology by Month, 2006
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Year
28
Aug
Sep
Oct
Nov
Dec
Arboviral Infections
Background
Arboviruses that cause encephalitis are members of the Togaviridae, Flaviviridae
or Bunyaviridae families. Humans and domestic animals, such as horses, can develop
clinical disease but are usually dead-end hosts because they do not develop sufficient
viremia to contribute to the transmission cycle. Arboviral infections that have ever been
reported in Illinois residents due to exposure in Illinois include those due to St. Louis
encephalitis (SLE), West Nile virus (WNV), California encephalitis (CE) and Western
equine encephalitis (WEE) viruses. WEE has not been seen in Illinois since the 1960s.
The most likely mosquito-borne diseases to occur in people in Illinois as of 2004 are
WNV and CE.
WNV background
WNV is a flavivirus in the Japanese encephalitis antigenic complex. Birds become
infected from mosquitoes. Bird-to-bird transmission also may occur. WNV is maintained
in a bird-mosquito-bird cycle with passerine birds as the primary amplifiers. Mosquitoes
from the Culex genus are the primary WNV vectors. The incubation period for WNV is
three to 14 days in people. WNV can cause a wide variety of clinical syndromes,
including fever, meningitis, encephalitis and a flaccid paralysis characteristic of a
poliomyelitis-like syndrome. About 80 percent of human infections are asymptomatic.
Febrile illness (fever, headache, fatigue, backache, myalgia) is not uncommon.
Gastrointestinal symptoms and a rash also may occur. The rash is usually
maculopapular and appears between days five to 12 of illness. WNV produces a viremia
that tends to disappear with the onset of clinical symptoms. Persons with West Nile
meningitis often are hospitalized for pain control or rehydration. Most patients return
home to independent living. West Nile encephalitis occurs more often in persons with
immunosuppression or persons greater than 55 years of age. Physical, occupational or
speech therapy is frequently needed in patients following West Nile encephalitis.
Approximately 75 percent may require some type of assisted care after West Nile
encephalitis. IgM antibodies can persist for up to a year following infection. Screening of
blood donations for WNV began in June 2003. In a study of blood donors, the median
time from WNV RNA detection to IgM seroconversion was four days and eight days to
IgG conversion. The mean time to IgM negativity was 156 days.
A study in Ohio in 2002 showed that only 44 percent of their study population
avoided mosquitoes and only 17 percent used repellents regularly. Children spent more
time outside than adults. Most of the information about WNV was obtained from
television.
In the United States, total human cases reported to CDC by year are as follows,
2000 (21), 2001 (66), 2002 (4,156), 2003 (9,862), 2004 (1,604) and 2005 (3,000) and
2006 (4,269). In 2006, 1,459 neuroinvasive, 2,616 WNV fever and 194 other clinical
cases were reported in the United States from 43 states with 177 deaths reported. WNV
activity occurred in 48 states. In Washington state, cases were reported for the first time.
More than 30 percent of WNV neuroinvasive cases were from three states (Idaho, Illinois
and Texas). In addition, 43 states reported WNV-infected dead birds, and 34 states
reported WNV-infected horses. Culex mosquitoes accounted for 73 percent of WNV
positive pools. From 2002 to 2006, cumulative incidence per state of WNV neuroinvasive
29
disease ranged from 0.2 to 32.2 per 100,000 population. The highest rates were in the
northern Great Plains.
California encephalitis background
CE virus is the main cause of pediatric encephalitis in the United States. The
illness occurs most commonly in children younger than 15 years of age. In Illinois, cases
of CE virus infection are most often reported from Peoria, Tazewell and Woodford
counties. The main vector is thought to be Ochlerotatus triseriatus (tree hole
mosquitoes), a container-breeding mosquito. Therefore, human activities which can
increase the numbers of containers, such as tires or buckets, can increase the
population of the tree hole mosquito. In 2006, the IDPH lab tested only those persons
negative for WNV and younger than 18 years of age for CE due to limitations on
reagents for testing. A total of 67 cases were reported in the United States from 12
states.
Saint Louis encephalitis and other arboviruses background
SLE also can be identified in persons in Illinois. In 2006, 10 cases of SLE were
reported from eight states. In the United States, there were also eight cases of EEE
reported, one case of Powassan and no cases of WEE.
Non-endemic arboviruses background
Several arboviruses seen in Illinois result from traveling overseas, including
Dengue and Chikungunya. Chikungunya virus is transmitted by the Aedes mosquito. And
is indigenous to tropical Africa and Asia. The primary reservoirs are primates and
rodents. The incubation period is usually two to four days. Chikungunya virus is an
illness characterized by fever, myalgias, lower back pain and arthralgias accompanied by
rash and conjunctivitis. The arthritis primarily affects smaller joints such as the wrists and
ankles. Most Chikungunya infections are asymptomatic. The diagnosis should be
considered in travelers to endemic areas who have fever and arthritis. Serologic testing
may be negative during the first week of infection. RT-PCR testing may be more
sensitive early in the course of illness. Patients may be viremic for six to seven days
(shortly before and during the febrile period). No autochtonous cases have occurred yet
in the United States. Treatment consists of supportive care, including analgesics and
anti-inflammatory medications. From 2005 to 2006, an epidemic occurred on islands in
the Indian Ocean and in India. Thirty-seven cases were reported in United States
travelers in 2006. In 2006, Chikungunya cases were also reported in residents of
Europe, Canada, the Caribbean and South Africa after travel to endemic areas. In a
study of travelers in 2006 with symptoms of Chikungunya, travelers to the Indian Ocean
Islands (Mauritius, Reunion and Madagascar) had the highest risk of infection. A rash
was typically associated with the Chikungunya cases.
Dengue is an arbovirus caused by four serotypes (DEN-1, DEN-2, DEN-3 and
DEN-4). Dengue is the most common arbovirus in tropical and subtropical parts of the
world. United States residents who travel to countries with endemic Dengue are at risk
for the disease. The incubation period ranges from three to 14 days. Dengue infection
can range from asymptomatic to mild to severe disease. A second infection with a
different serotype can result in Dengue hemorrhagic fever. Persons traveling to areas
with Dengue should wear repellents and protective clothing. Diagnosis is by acute and
convalescent serum samples. Dengue is not nationally notifiable. In a study of travelers
30
visiting a GeoSentinel surveillance clinic, 6 percent of persons returning with febrile
illness had Dengue.
Arbovirus prevention background
Arboviral encephalitis prevention includes limiting mosquito bites in humans and
reducing mosquito habitat. Mosquito bites can be minimized by using appropriate
repellents, by avoiding the outdoors during peak mosquito feeding times and by repairing
screens on windows and doors. The use of repellents provides the best protection
against mosquitoes. Prevention involves personal protective behaviors and mosquito
control activities. People can eliminate breeding areas for mosquitoes such as standing
water in clogged rain gutters.
During the period May 15 through October 31, physicians and laboratories in
Illinois are encouraged to submit cerebrospinal fluid (CSF) from aseptic meningitis and
encephalitis cases to the Department laboratory for further testing. In addition, serum
samples are requested for testing for arboviral antibody from clinically compatible cases.
The CSF can be examined for antibodies to LAC, SLE and Eastern equine encephalitis.
Case definition
The case definition for a confirmed case of arboviral encephalitis in Illinois is a
clinically compatible illness that is laboratory confirmed at either commercial laboratories
or public health laboratories. The laboratory criteria are a fourfold or greater rise in serum
antibody titer; or isolation of virus from, or demonstration of viral antigen in tissue, blood,
CSF or other body fluid; or specific IgM antibody in CSF. A probable case of arboviral
encephalitis is a clinically compatible illness occurring during the season when arbovirus
transmission is likely to occur and with the following supportive serology: a stable
(twofold or smaller change) elevated antibody titer to an arbovirus, e.g., at least 320 by
hemagglutination inhibition, at least 128 by complement fixation (CF), at least 256 by IF,
at least 160 by neutralization, or a positive serologic result by enzyme immunoassay
(EIA).
Descriptive epidemiology
California encephalitis surveillance
No cases of California encephalitis were identified in Illinois in 2006.
•
Past incidence - The reported cases of CE in Illinois are as follows: 1990 (one),
1991 (15), 1992 (seven), 1993 (two), 1994 (six), 1995 (five), 1996 (13), 1997
(three), 1998 (four), 1999 (three), 2000 (three), 2001 (five), 2002 (eight), 2003
(11), 2004 (eight) and 2005 (one) (Figure 21).
Chikungunya Surveillance
• Number of cases reported in Illinois – Seven Chikungunya cases were reported in
Illinois. Two cases were confirmed, and five cases were classified as probable.
Virus was isolated from one patient specimen at CDC.
• Age – Ages ranged from 29 to 78 years of age. The mean age was 57.
• Gender – Five cases were male and two were female.
• Race/ethnicity –Six of the cases were Asian and one was white. None reported
31
•
•
•
•
•
•
Hispanic ethnicity.
County of residence – Five of the cases resided in Cook County, and one each of
the cases resided in DuPage County and Will County.
Clinical syndrome – Seven of the cases reported fever, six reported joint pain, and
two each reported rash, weakness and vomiting.
Treatment - Two of three cases with a known hospitalization history were
hospitalized. Of three cases with information available, none died.
Seasonal distribution – Case onsets were reported from June through November.
Travel – All cases had traveled to India prior to illness onset.
Case descriptions
o One case was a 65-year-old female who traveled to India from May 27 to
June 25. She had onset of illness on June 5. Serum was collected on July
5. She would not have been viremic upon her return to the United States
on June 25.
o A second case was a 53-year-old male with travel to India (return date
August 17). Onset of illness was August 3 with serum collected on August
23. The patient may have been viremic while in the United States.
o A third case was a 40-year-old Will County resident who traveled to India
(dates not specified). Onset of illness was July 28 and serum was collected
on September 12 (Day 46).
o The fourth case was a 29-year-old male who had travel to India from June
24 through August 9. Onset of illness was August 4 and serum was
collected on September 5 (day 35).
o The fifth case was a 74-year-old male from Cook County with onset on
November 3. He traveled to India from May 1 through November 1.
o The sixth case was a 61-year-old male with onset of July 16. He traveled to
India from June 21 through July 9.
o The final case was a 78-year-old Asian male from Cook County with onset
on September 29. He traveled to India from September 15 to September
29. Virus was isolated from this patient at CDC.
SLE surveillance
Occurrence - No cases of SLE were reported in 2006.
Dengue surveillance
• Number of cases reported in Illinois – Six cases of dengue were reported in 2006;
all were designated as probable.
• Geographic Distribution - Cases were reported from Cook (three), DuPage (two)
and Winnebago (one) counties.
• Age – The age of the cases ranged from 27 to 66 years. The mean age was 44
years.
• Gender – Four of the cases were male and two were female.
• Race/ethnicity – The race of three cases was known. Two were white and one
was African American; one case was Hispanic.
• Clinical presentation – All cases developed a fever.
• Hospitalization – Three cases were hospitalized.
• Fatalities – No fatalities were reported.
32
•
•
•
Travel – All cases had a history of travel outside of the continental United States.
Three traveled to Mexico, one to the Philippines, one to Puerto Rico and one to
an unknown destination.
Seasonal distribution – Onsets of cases were reported from March through
November.
Past incidence - The reported cases of dengue in Illinois residents for prior years
are as follows: 1990 (none), 1991 (none), 1992 (none), 1993 (one), 1994 (two),
1995 (two), 1996 (none), 1997 (four), 1998 (one), 1999 (two), 2000 (two), 2001
(two) and 2002 (none), 2003 (none), 2004 (three) and 2005 (one).
West Nile virus surveillance
More than 60 agencies participated in bird and mosquito surveillance in Illinois in 2006.
Human
• Number of cases reported in Illinois – Two hundred fifteen WNV cases were
reported; 84 (39 percent) were confirmed and 131 (61 percent) were classified as
probable. The incidence in Illinois was 1.7 cases per 100,000 population.
• Age – Ages ranged from 2 years to 91 years of age (mean = 53 years) (Figure
22).
• Gender – One hundred twelve (52 percent) of the cases were male.
• Race/ethnicity – Cases reported the following race, white (85 percent), African
American (9 percent) and other (3 percent). Six percent of 168 cases reported
being Hispanic.
• Clinical presentation – Cases were classified as: WNF (69), neuroinvasive
disease (127) and other (19) (Figure 23). Of the neuroinvasive cases, 76 were
classified as encephalitis, 46 were classified as meningitis and five were classified
as flaccid paralysis. For individuals older than 59 years of age, 69 percent had
neuroinvasive disease as compared to 53 percent of those younger than 60 years
of age. Cases exhibited the following symptoms: fever, 187 (89 percent); stiff
neck, 69 (35 percent); rash, 65 (33 percent) and change in consciousness, 61 (33
percent). Sixteen persons were reported to have been on ventilators.
• Hospitalization – One hundred fifty of 199 (75 percent) cases were hospitalized.
• Fatalities – Ten cases were fatal. Due to age and underlying illness the direct
cause of death may not have been WNV. All but two fatal cases had
neuroinvasive disease. Fatal cases ranged in age from 56 to 90 years of age
(mean = 76 years).
• Diagnosis – The Department’s laboratory performed the MAC ELISA test on all
submitted specimens. This was the first year that clinically compatible cases
without laboratory confirmation at a public health laboratory could be counted as
cases in Illinois. Of the reported cases, positive tests occurred as follows: both
serum and CSF (39), CSF only (42) and serum only (134).
• Seasonal distribution – Onset of cases ranged from May 27 (Kane County)
through October 11 (Moultrie County). The highest number of case onsets
occurred in August. Figure 24 shows the number of WNV infections by week.
• Geographic distribution – Thirty-eight counties had evidence of WNV activity in
humans (Figure 25). The largest number of cases per county (86, 40 percent)
occurred in Cook County (incidence per 100,000 population = 1.5). Incidence
33
•
•
rates in selected other counties were DuPage (43, 5 per 100,000), Will (18, 4 per
100,000) and Lake (11, 2 per 100,000).
Reporting – Of the 200 cases with the reporting source listed, the most frequent
reporters were infection control professionals (48 percent) and laboratory staff (51
percent).
Historical – The number of cases in Illinois was 2002 (884), 2003 (53), 2004 (60),
and in 2005 (252).
Bird testing
The number of counties submitting birds for WNV testing: 2004 (69), 2005 (62),
and 2006 (89). Fifty-six counties in 2006 reported positive birds (63 percent of counties
submitting birds for testing). Bird types that could be submitted for WNV testing was
expanded to include robins, grackles, starlings, house sparrows, blackbirds, cardinals
and mourning doves as well as crows and blue jays. The total submitted for each
species : crow (90, 64 percent positive), blue jay (57, 54 percent), house sparrow (14, 21
percent), house finch (10, 20 percent), grackle (39, 10 percent) and robin (83, 8 percent).
In August, 40 percent of robins tested positive. Twenty-six other types of birds were
submitted with 8 percent testing positive. Birds submitted but not testing positive
included mourning dove (seven), cardinal (six), blackbird (eight) and starling (13). Birds
were tested using immunohistochemistry testing (IHC).
The first positive bird of the season was collected on May 24 from Cook County
and the last positive bird of the season was collected on November 30 from Cook
County.
Mosquito pool testing
In 2006, 45 of 62 counties submitting mosquito pools for testing (73 percent) had
pools which tested positive. For 2004 and 2005, 48 percent of counties had mosquito
pools that tested positive. The mosquito pool testing was 2004 (66 counties submitted,
with 32 positive) and 2005 (64 submitted, 31 positive). The first positive mosquito sample
was collected on May 20, 2006. In 2006, of 4,047 mosquito pools (26 percent) tested
positive.
WNV horse testing
Twenty-one horses were reported with WNV in 2006. Seven horses died or were
euthanized due to WNV resulting in a 33 percent fatality rate. None of the 21 horses
were up-to-date on WNV vaccination. Horses were from Boone (two), Bureau (two),
Effingham (two), Will (two) and one each from Christian, Henderson, Henry, Jackson,
Kankakee, Lake, LaSalle, Lawrence, Lee, Marion, McHenry, Randolph and Sangamon.
Date of report ranged from August 22 (Marion County) to October 29 (Jackson County).
All were symptomatic and all tested positive by IgM ELISA.
Other species
No other animals were positive for WNV in 2006.
Summary
Because encephalitis cases are more commonly reported in the summer months
in Illinois, the Department asks physicians to increase testing to establish the etiology
34
and to report individuals with acute encephalitis from May 15 to October 31 each year.
This was the fifth year for humans to test positive for WNV in Illinois. Dead crows and
blue jays tested positive for WNV in counties in Illinois. Positive dead birds were
collected in Illinois between May 24 and November 30.
There were no cases of CE and no cases of SLE reported in 2006. Illinois had the
second highest number of reported WNV cases in the United States. During 2006,
human WNV cases were reported from 38 of the 102 counties in Illinois. In 2006, the
majority of the cases were in the Chicago metropolitan area.
Suggested readings
Borgherini, G., et al. Outbreak of Chikungunya on Reunion Island: Early Clinical
and Laboratory Features in 157 Adult Patients. CID 2007; 44:1401-07.
Brown, H.E. et. al., Ecological factors associated with West nile virus
transmission, Northeastern United States. Emerg Inf Dis 2008;14(10):1539-45.
Division of Vector Borne Infectious Diseases, National center for Zoonotic, Vectorborne, and enteric diseases et al. Update: Chikungunya fever diagnosed among
international Travelers – United States, 2006. MMWR March 30, 2007; 276-77.
Busch, M.P., et. al., Virus and antibody dynamics in acute West Nile virus
infection. JID 2008;198:984-993.
Lanciotti, R.S., et al. Chikungunya virus in US travelers returning from India, 2006.
Emerg Inf Dis 2007;13(5): 764-7.
LeBeaud, A.D., et. al., Exposure to West Nile virus during the 2002 epidemic in
Cuyahoga County, Ohio: A comparison of pediatric and adult behaviors. Pub Health
Reports 2007;122 :356-361.
Lindsey, N.P., et al. West nile virus neuroinvasive disease incidence in the United
States, 2002-2006. Vector-borne and zoonotic diseases 2008; 8(1), 35-39.
Nicoletti, L., et al. Chikungunya and Dengue viruses in travelers. Emerg Inf Dis
[serial on the internet]. 2008 Jan. Available from
http://www.cdc.gov/EID/content/14/1/177.htm.
Sejvar, J.J. The long-term outcomes of human West Nile virus infection. CID
2007;44:1617-24.
Taubitz, W., et al. Chikungunya fever in travelers: Clinical, presentation and
course. CID 2007;45:1-4.
Warner, E., et al. Chikungunya fever diagnosed among international travelers –
United States, 2005-2006. MMWR 2006; 55(38):1040-2.
Wichmann, O., et al. Severe Dengue Virus Infection in Traveler : Risk Factors and
Laboratory Indicators. JID 2007; 195; 1089-96.
Wilder-Smith, A. and Tambyah, P.A. Severe Dengue Virus Infection in Travelers.
JID 2007; 195:1081-83.
Wilson, M.E., et al. Fever in returned travelers: Results from the GeoSentinel
surveillance network. CID 2007;44:1560-8.
35
Number of cases
Figure 21. California Encephalitis Cases in Illinois, 2001-2006
15
11
9
8
10
5
5
1
0
0
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 22 . Reported WNV Cases in Illinois by Age, 2006
80
60
40
20
0
0-14 yrs
15-29 yrs
30-44 yrs
45-59 yrs
60-74 yrs
>74 yrs
Age category
Figure 23. Clinical Syndrome for WNV Cases in Illinois, 2006
Other
11%
WNV aseptic
meningitis
21%
WNV fever
32%
WNV fever
WNV encephalitis
WNV aseptic meningitis
Other
WNV encephalitis
36%
Number of cases
Figure 24. Epidemic Curve for Human WNV Cases in Illinois, 2006
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Week of onset
36
Aug
Sep
Oct
Nov
Dec
Figure 25. Map of Human WNV Cases in Illinois by County, 2006
37
Haemophilus influenzae (Invasive Disease)
Background
Haemophilus influenzae is an obligate pathogen of the human respiratory tract
and can cause invasive disease such as meningitis, septic arthritis, pneumonia,
epiglottitis and bacteremia. H. influenzae forms part of the normal flora of the human
throat and is divided into six serotypes (a through f). The polysaccharide capsule is a
known virulence factor and is the antigen used in serotyping. The organism is
transmitted by droplets and discharges from the nose and throat. The incubation period
is probably short, from two to four days. Children younger than 5 years of age should be
vaccinated against H. influenzae. Prior to the introduction of vaccine against serotype b,
most cases were due to serotype b.
In 2006, 383 cases were reported in those younger than 5 years of age in the
United States. Eight percent of all cases in children younger than five years of age were
attributable to type B. Incidence has declined 99 percent since the pre-vaccination time
period. In the post-vaccine era, nontypable serotypes have increased. In the United
States, the incidence of all cases of invasive H. influenzae was 0.82 per 100,000
population.
In the CDC Active Bacterial Core (ABC) Surveillance System sites in 2006, 3
percent of H. influenzae isolates were type B and 71 percent were non typable. The
incidence was 1.6 per 100,000 at these sites.
Case definition
The case definition for a confirmed case of invasive H. influenzae in Illinois is a
clinically compatible illness with isolation of the organism from a normally sterile site. A
probable case is a clinically compatible illness and detection of H. influenzae type b
antigen in CSF.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 120 (five-year median = 120). The
incidence was 0.96 per 100,000. All cases were confirmed. From 2001 to 2006,
the number of cases reported per year ranged from 103 to 135 (Figure 26).
• Age – Fifty-six percent of the cases were older than 49 years of age (mean = 55
years of age) (Figure 27). Two type b cases were in persons younger than 5years
of age.
• Gender - Fifty-five percent of cases were female.
• Race/ethnicity - Fourteen percent were African Americans, 83 percent were white,
and 3 percent were other races; 12 percent were Hispanic.
• Seasonal distribution – H. influenzae occurs throughout the year, with an increase
in the winter months (Figure 28).
• Presentation – The case presentations were bacteremia (61 percent), pneumonia
(24 percent), meningitis (9 percent), other (4 percent) and multiple (2 percent).
• Treatment – Ninety-two percent of 111 reported cases for which information was
available were hospitalized.
• Serotype results – Typing results were available for 101 of 120 (84 percent) of
isolates. For the 101 cases with typing available, the following serotypes were
identified: f (20 cases), b (11 cases), e (nine cases), d (two cases) and a (four
38
•
•
•
•
•
cases. Eleven percent were type b. Fifty-five (54 percent) of the isolates were
non-typable.
Mortality – Nine of 75 (12 percent) cases for which information was available died.
Ages of the fatal cases ranged from 78 to 100.
Diagnosis - All cases were culture confirmed. H. influenzae was isolated from
blood (102 cases), CSF (six cases) and CSF and blood (four).
Geographic location – Thirty-five percent of the cases resided in Cook County.
Epidemiology – One case was from a day care facility and five lived in residential
facilities.
Reporting – All cases had a reporter listed. Reporters included infection control
professionals (94), laboratory staff (22), and other (four).
Summary
The number of H. influenzae cases in 2006 was the same as the five-year
median. The incidence in Illinois (0.96 per 100,000) was lower than in CDC’s ABC sites
(1.6 per 100,000). Of the isolates that were typed, 11 percent were type b as compared
to 3 percent in CDC’s ABC sites. Cases occur throughout the year. Two type b cases
occurred in children younger than 5 years of age for whom the vaccine is indicated. The
11 percent of isolates serotyped as type b was similar to the 13 percent seen in 2005.
Fifty-four percent of cases in 2006 were untypable as compared to 71 percent in CDC’s
ABC site in 2006. Fifty-six percent of all cases occurred in people older than 49 years of
age.
Suggested readings
CDC, 2007. Active bacterial core surveillance report, Emerging Infections
Program Network, Haemophilus influenzae, 2006. Available via the Internet:
http://www.cdc.gov/ncidod/dbmd/abcs/survreports/hib06.pdf
Tsang, R.S.W., et al. Characterization of invasive Haemophilus influenzae
disease in Manitoba, Canada, 2000-2006: Invasive disease due to non-type B strains.
CID 2007;44:1611-4.
39
Number of cases
Figure 26. H. influenzae Cases in Illinois, 2001-2006
150
135
120
103
124
109
120
100
50
0
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 27. H. influenzae Cases by Age in Illinois, 2006
80
60
40
20
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-59 yr
>59 yr
Year
Number of cases
Figure 28. H. influenzae Cases in Illinois by Month, 2006
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
40
Aug
Sep
Oct
Nov
Dec
Listeriosis
Background
Listeriosis is caused by infection with Listeria monocytogenes, which is common
in the environment. It is a foodborne illness that can cause sepsis in
immunocompromised persons and meningoencephalitis and febrile gastroenteritis in
immunocompetent persons. Febrile gastroenteritis is considered to be uncommon. A
study in Canada identified only 17 cases of L. monocytogenes in 8,000 stool specimens
submitted for diagnosis of a diarrheal illness.
Patients receiving antineoplastic therapy are more susceptible to listeriosis.
Bloodstream infection, sepsis and meningitis are typical clinical presentations. Listeriosis
has the highest case fatality rate of any foodborne illness. Pregnant women whose
gastrointestinal tracts become colonized with the bacteria after they eat contaminated
foods can transmit the organism to the fetus or can contaminate the baby’s skin or
respiratory tract during childbirth.
The median incubation period is three weeks, which makes identifying a suspect
food vehicle difficult. L. monocytogenes is found frequently in nature and can be cultured
from foods and the environment, which makes typing of isolates from patients and
suspected food items important. The majority of isolates from cases are 1/2 a, 1/2 b or
4b. Pulse field gel electrophoresis can be used to further discriminate between isolates.
Contaminated food vehicles often identified in outbreaks of listeriosis in the United States
include unpasteurized dairy products. However, other vehicles have been identified.
L. monocytogenes can resist salt, heat, nitrite and acidity better than many other
organisms. It also can survive and multiply at cold temperatures. Refrigerators at 40° F
or below are best for reducing the potential for listeriosis.
Of the 10 diseases/syndromes under active FoodNet surveillance (those caused
by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), listeriosis
comprised 138 of 17,252 (0.8 percent) of the reported infections in 2006. Incidence rates
ranged from 0.1 to 0.5 per 100,000 at the 10 sites with an overall incidence of cases of
0.3 per 100,000 population.
In 2006, 884 cases of listeriosis were reported to CDC from 48 states and
territories.
Case definition
Illinois uses the CDC case definition for Listeria cases: a clinically compatible
history (stillbirth, listeriosis of the newborn, meningitis, bacteremia or localized infection)
and isolation of L. monocytogenes from a normally sterile site. In the setting of
miscarriage or stillbirth, isolation of L. monocytogenes from placental or fetal tissue is
adequate as laboratory confirmation. A maternal-child pair will only be counted as one
maternal case.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 31 total (five were described as
cases of meningitis). All cases were confirmed. The five-year median is 24 (Figure
29). The 2006 incidence for all reported listeriosis was 0.24 per 100,000
population.
41
•
•
•
•
•
•
•
•
•
•
•
Age - Cases ranged in age from younger than 1 year to 91 years of age; 77
percent of cases were older than 59 years of age.
Seasonal distribution – Cases occurred from January through December.
Gender – Fifty-two percent of cases were female.
Race/ethnicity - Seventy-nine percent of the cases were white, 14 percent were
African American and 7 percent were other races. Nine percent reported Hispanic
ethnicity.
Geographic location – Eleven of the 31 cases were reported from Cook County.
Ten counties reported cases.
Diagnosis - The site of Listeria isolation was identified as follows: blood (25),
cerebrospinal fluid (two), blood and CSF (one), peritoneal fluid (one), fetus (one
and brain (one). CDC typed seven isolates. They were typed as 4b (three), 1 /2 a
(three) and 1 / 2 b (one).
Underlying conditions – Twenty-five of 28 (89 percent) cases with information
available on immunosuppressive conditions reported an immunosuppressive
condition. These included pregnancy, cancer, diabetes mellitus, renal
disease/dialysis or steroid therapy.
Clinical – All cases were hospitalized. One case had a spontaneous abortion. Two
of 25 cases with information on mortality died. The fatal cases were 16 and 91
years of age.
Epidemiology – Five cases resided in a residential facility.
Reporting – Ninety percent of cases were reported by infection control
professionals and 10 percent by laboratory staff.
There were no outbreaks of reported listeriosis in Illinois in 2006.
Summary
In 2006, Illinois recorded 31 listeriosis cases; 77 percent of the cases were older
than 59 years of age. The incidence rate (0.24) was within the range described by CDC’s
FoodNet sites in 2006 (0.1-0.5 per 100,000).
Number of cases
Figure 29. Listeriosis Cases in Illinois, 2001-2006
40
30
32
24
23
24
31
24
20
10
0
2001
2002
2003
2004
Year
42
2005
2006
Invasive Neisseria meningitidis
Background
N. meningitidis is an important cause of bacterial meningitis and septicemia in the
world. The bacteria that causes meningococcal disease, N. meningitidis, is carried in the
pharynx by about 5 percent to 10 percent of the population. The organism is transmitted
by direct contact with respiratory droplets from the nose and throat of an infected person.
Most patients acquire infection from an asymptomatic carrier during face-to-face contact
including coughing, sneezing and kissing and the sharing of drinks, foods and cigarettes.
The incubation period ranges from two to 10 days and is usually three to four days.
Meningococcal disease is an acute bacterial disease that may be characterized by fever,
headache, stiff neck, delirium and, often, a rash and vomiting. It presents as meningitis
in 80 percent to 85 percent of cases. Septicemia also can result from infection with N.
meningitidis. The overall case fatality rate is between 10 percent and 14 percent. Eleven
percent to 19 percent of survivors have permanent sequelae. Carriage of the
meningococcus organism is transient and the level of carriage does not predict the
course of an outbreak. Less than 1 percent of exposed persons who become infected
develop invasive disease. Rates are highest in infants.. Among those aged 11 to 19
years, 75 percent of cases are caused by A, C, Y, W-135. The majority of cases in
infants are group B.
Antimicrobial chemoprophylaxis is used for close contacts of cases. Only close
contacts should be given chemoprophylaxis due to concerns about antimicrobial
resistance. Vaccination can be used as an adjunct measure to protect against A, C, Y
and W135 serogroups. A meningococcal vaccine that protects against these serogroups
was licensed in the United States in 1982. It is given routinely to military recruits and to
certain travelers. A second vaccine using conjugate technology was approved in early
2005 for protection against the same four serotypes among persons aged 2 to 55 years.
A conjugate vaccine against serogroup B has been used successfully in some settings
overseas. It has not been approved for use in the United States. Vaccination campaigns
are used in highly selected situations. One vaccination campaign occurred in New York
City after 23 cases of N. meningitidis group C were identified. Eighty-three percent of
cases with the same PFGE pattern over a one-year period were in persons using illicit
drugs. One control measure was use of vaccination in the community at risk with 2,763
persons receiving vaccine.
In May 2005, CDC recommended routine vaccination with meningococcal vaccine
for adolescents, college freshman living in dormitories, and others at high risk for
meningococcal disease. There may be a small risk of Guillain-Barre syndrome following
meningococcal vaccination but this risk must be evaluated further.
A national immunization survey in 2006 of adolescents aged 13 to 17 identified
that meningococcal vaccine had been received by 12 percent of adolescents nationally.
In 2006, 1,194 cases were reported in the United States. In the CDC Active
Bacterial Core Surveillance sites in 2006, 46 percent of cases presented with meningitis.
The percent of cases with each serogroup was Y (40 percent), B (28 percent), C (28
percent) and other (7 percent). The national estimate for invasive disease is 0.30 per
100,000 for 2006.
Completeness of reporting is important because close contacts to N. meningitidis
cases need chemoprophylaxis. A study in Maine from 2001 to 2006 comparing reported
cases and hospital discharge data showed that 98 percent of cases were reported.
43
Case definition
The case definition for a confirmed case of meningococcal disease is a clinically
compatible case with N. meningitidis isolated from a normally sterile site or from skin
scrapings of purpuric lesions. The case definition for a probable case is a compatible
illness with PCR positive from a normally sterile site or evidence of N. meningitidis from
latex agglutination of CSF or positive immunohistochemistry on formalin fixed tissue. A
suspect case has clinical purpura fulminans in absence of positive blood culture or
clinically compatible case with gram negative diplococci from a normally sterile site.
Suspect cases are not counted as official cases in the case count for Illinois.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 46 (incidence of 0.4 per 100,000)
(five-year median = 57) (Figure 30). Forty-two cases were confirmed and four
were probable. Three cases were reported to be in college students and five
cases were reported to be day care attendees. One case resided in a homeless
shelter.
• Age - The age distribution of reported meningococcal disease is shown in Figure
31. Mean age of cases was 39 (range: younger than 1 year to 86 years of age)
• Gender – Forty-four percent of cases with gender information were female.
• Race/ethnicity – Twenty-six percent of cases were African American and 71
percent were white; 18 percent were Hispanic.
• Seasonal distribution - Meningococcal disease occurred throughout 2006 with
increases in the winter (Figure 32).
• Geographic location – Forty-eight percent of reported cases were from Cook
County.
• Presentation – For 44 cases with case reports, the presentation of illness was
bacteremia (52 percent), meningitis (43 percent), pneumonia (2 percent) and
septic arthritis (2 percent).
• Diagnosis - The organism was isolated from blood only (27 cases), CSF only
(nine), blood and CSF (six) and joint fluid only (one). For three probable cases,
diagnostic testing included identification of gram negative diplococci (two) and
antigen testing of CSF (one). Serogrouping was performed on isolates from 40
(87 percent) of cases. In cases where typing was done, the serogroups identified
were Y (37 percent), C (17 percent), B (32 percent), W-135 (5 percent), Z (2
percent) and nontypable (5 percent) (Figure 33).
• Treatment – Forty-one of 45 (91 percent) of individuals with information available
were hospitalized.
• Mortality - The case fatality rate was 20 percent for 30 patients where the
outcome of infection was known. Ages of the six fatal cases were 13,17, 44, 55,
69, and 86 years of age.
• Reporting – Nineteen cases were reported by infection control professionals.
• Clusters – None reported. No clusters requiring a vaccination campaign occurred
in 2006.
44
Summary
The number of N. meningitidis cases reported in Illinois in 2006 (46) was lower
than the five-year median (57 cases). The incidence in Illinois (0.4 per 100,000) was
higher than the national estimates of incidence for 2006 (0.3 per 100,000). Eighty-seven
percent of isolates were serogrouped. Serogroup Y was the most common serogroup
reported.
Suggested readings
CDC. 2007. Active bacterial core surveillance report, Emerging Infections
Program network, Neisseria meningitidis, 2006. Available via the Internet:
http://www.cdc.gov/ncidod/dbmd/abcs/survreports/mening06.pdf.
Clarke, C. and Mallonee, S. State-based surveillance to determine trends in
meningococcal disease. Pub Health Reports 2009; 124:280-87.
Jain, N. National vaccination coverage among adolescents aged 13-17 yearsUnited States, 2006. MMWR 2007;56 (34): 885-888.
Rea, V. Completeness and timeliness of reporting of meningococcal disease –
Maine, 2001-2006. MMWR 2009; 58(7):169-172.
Weiss, D., et. al. Epidemiologic investigation and targeted vaccination initiative in
response to an outbreak of meningococcal disease among illicit drug users in Brooklyn,
New York. Clin Inf Dis 2009;48:894-901.
Number of cases
Figure 30. Meningococcal Disease in Illinois, 2001-2006
100
80
60
40
20
0
88
73
57
36
2001
2002
2003
2004
Year
45
34
2005
46
2006
Number of cases
Figure 31. N. meningitidis Cases by Age in Illinois, 2006
15
10
5
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-59 yr
>59 yr
Year
Number of cases
Figure 32. N. meningitidis Cases in Illinois by Month, 2006
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Number of cases
Figure 33. N. meningitidis Cases in Illinois by Serogroup, 1993-2006
80
B
60
C
40
Y
20
Other
0
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
Year
46
Invasive Group B Streptococcus
Background
Group B streptococcus and E. coli cause most cases of sepsis in infants. Around
10 percent to 35 percent of pregnant women may be colonized with group B
streptococcus at the time of labor placing them at risk for transmitting the disease to their
infants.
Group B streptococcus infections are due to Streptococcus agalactiae and cause
disease and death in newborns and morbidity in peripartum women and nonpregnant
adults with chronic medical conditions. Early-onset disease of neonates (less than seven
days) may consist of sepsis, respiratory distress, apnea, shock, pneumonia and
meningitis. The infection is acquired during delivery or in utero. Early-onset disease is
caused by maternal group B streptococcus carriage. Risk factors for early-onset group B
streptococcus sepsis (that occur within 72 hours of life) include fever in the mother
during labor, preterm delivery, membrane rupture greater than 18 hours before delivery
and a mother with a previous infant with group B streptococcus. Infants acquire infection
through aspiration of contaminated amniotic fluid or during passage through the birth
canal. Late-onset disease (seven days to several months) is characterized by sepsis and
meningitis and is acquired by person-to-person contact. Only about 50 percent of lateonset disease cases have been shown to be of maternal origin.
Case definition
A confirmed case of invasive group B streptococcus disease is defined as
isolation of GBS from a normally sterile site (e.g., blood or cerebrospinal fluid). A
probable case is defined as a person who is latex agglutination positive for group B
streptococcus from a sterile site. Only cases younger than 3 months of age were
required to be reported in Illinois in 2006.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 89; 65 cases were less than 3
months of age. Twenty-four cases were in older age groups.
• Age – Thirty-four of 65 (52 percent) of cases were younger than 3 months of age.
Only cases younger than three months of age are reportable.
• Gender – Thirty-four of 65 (52 percent) of all cases younger than 3 months were
female. Sixty-two percent of those older than three months were female.
• Race/ethnicity – Forty-five percent of all cases younger than three months were
white and 42 percent were African American; 27 percent were Hispanic. There
was a significantly higher proportion of African Americans with GBS as compared
to their representation in the Illinois population.
• Seasonal variation – Thirty-eight of 65 (58 percent) of cases younger than 3
months of age had onsets from August to December.
• Diagnosis – All reported cases (all ages) were confirmed by a positive culture.
The organism was isolated from blood (71 cases), CSF (12 cases), blood and
CSF (four cases) and other or unknown sites (one case).
• Case outcome – Sixty-three of 65 cases (97 percent) younger than 3 months of
age were hospitalized; two cases were known to be fatal. For those older than 3
months of age, 20 of 23 cases were hospitalized and two fatalities were among
47
•
this age group.
Reporter – Eighty of the 89 cases were reported by infection control professionals
Summary
Cases of invasive group B streptococcal disease in newborns can be prevented if
the appropriate guidelines are followed by health care providers. Eighty-nine cases of
group B streptococcus disease were reported in Illinois, the majority in those younger
than 3 months of age. Although only group B streptococcal disease in those younger
than 3 months of age is reportable, voluntary reporting of invasive group B streptococcus
disease in persons older than 3 months of age occurs.
48
Cholera
Background
Cholera is a bacterial enteric disease that causes sudden onset of severe watery
diarrhea and also may cause vomiting. Rapid dehydration and renal failure can occur.
Vibrio cholerae serogroups 01 and 0139 are associated with cholera. Serogroup 01 has
two biotypes: classical and El Tor. V. cholerae O139 is present in South East Asia.
Cholera is transmitted by ingestion of contaminated food or water. The incubation period
is usually two to three days. The U.S. Gulf Coast can be a source of the cholera
organism.
Epidemics of cholera are associated with consumption of contaminated water,
poor hygiene, poor sanitation and crowded living conditions. Cholera is one of three
diseases requiring international notification to the World Health Organization. All
domestically acquired cases had consumed seafood. Vaccines are available and are
administered to travelers to countries with cholera.
Case definition
A confirmed case of cholera in Illinois is a clinically compatible case (diarrhea
and/or vomiting) that is laboratory confirmed. Laboratory confirmation is through isolation
of toxigenic V. cholerae 01 or 0139 from stool or vomitus or serologic evidence of
cholera.
Descriptive Epidemiology
One cholera case was reported in Illinois in 2006. The case was a 58-year old
male with V. cholerae serotype 01, type inaba, biotype El Tor and was positive for
cholera toxin by PCR. The isolate was resistant to trimethoprin-sulfa methoxazol,
furazolindone, nalidixic acid, sulfisoxazol, and streptomycin. The patient traveled to India
for business before becoming ill. He was not vaccinated for cholera. While in India he
prepared local food and drank local water. He was not admitted to a hospital and
survived.
Summary
One case of cholera in Illinois occurred in 2006. Cholera is reported infrequently
and is usually associated with travel overseas. Illinois was one of four states reporting
cases in 2006.
47
Cryptosporidiosis
Background
Cryptosporidiosis is primarily a gastrointestinal disease that affects humans and
45 other species. Disease results from infection with Cryptosporidium species oocysts.
There are 12 species recognized. Two species, C. hominis (previously known as C.
parvum genotype 1) and C. parvum (previously known as C. parvum, genotype 2) are
the most important human pathogens. C. hominis is largely restricted to humans and C.
parvum to a range of species including sheep, cattle and humans. The organism is shed
in the feces in the form of an oocyst, which has a hard shell to protect it from the
environment. Oocysts are immediately infective upon excretion by an infected host and
can be shed for up to two weeks or longer in immunocompetent humans. Infection is
spread through person-to-person transmission, from direct contact with animals and by
swimming in contaminated water. Approximately one to three percent of the general
population may be excreting oocysts. The incubation period is an average of seven days
(range is one to 12 days). Predominant symptoms include profuse and watery diarrhea
accompanied by abdominal cramping. Infection in immunocompetent people lasts one to
two weeks. Persons at risk for more severe infection include young children, pregnant
women or persons with weakened immune systems.
Oocysts of cryptosporidia can be found in many types of water including untreated
surface water, filtered swimming pool water and even from chlorine-treated or filtered
drinking water. The minimum level of detectable oocysts that pose a public health threat
in domestic water supplies is not known. Outbreaks have occurred due to person-toperson and waterborne spread. Cryptosporidium is the leading cause of reported
outbreaks of gastroenteritis linked to treated swimming venues.
Of the 10 diseases under active surveillance in FoodNet sites (illnesses caused
by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica),
Cryptosporidium comprised 5 percent of the reported infections.
There was a preliminary incidence rate of 1.9 per 100,000 for Cryptosporidium
and incidence ranged from 0.8 to 4.7 at the ten FoodNet sites in 2006. In 2006, 6,071
confirmed cryptosporidiosis cases were reported to CDC through NETSS. The number of
cases was highest in those one to nine years of age. A tenfold increase occurred from
summer to fall.
Important features of cryptosporidiosis include: 1) waterborne outbreaks are
typical, 2) oocysts are resistant to commonly used disinfectants 3) transmission can
occur by direct fecal-oral contact, 4) as few as 10 to 100 oocysts can cause infection, 5)
oocysts are infectious upon excretion and 6) asymptomatic infections occur.
Prevention of outbreaks includes advising ill persons to wash hands with soap
and water after using the toilet and before eating or preparing food, to avoid swimming in
recreational water during illness and for at least two weeks after diarrhea stops and to
avoid fecal exposure during sexual activity. Environmental control measures, such as
hyperchlorination, may be needed when outbreaks in recreational water facilities are
discovered. The first treatment for cryptosporidiosis in the United States was introduced
in 2006 (nitazoxanide).
Case definition
A confirmed symptomatic case of cryptosporidiosis in Illinois is laboratory
confirmed (demonstration of Cryptosporidium oocysts in stool by microscopic
48
examination, or demonstration of Cryptosporidium in intestinal fluid or small bowel biopsy
specimens, or demonstration of Cryptosporidium oocyte or sporozite by a specific
immunodiagnostic test such as ELISA or by PCR techniques or demonstration of
reproductive stages in tissue preparations) and is associated with one of the following
symptoms: diarrhea, abdominal cramps, loss of appetite, low-grade fever, nausea or
vomiting. A confirmed asymptomatic case is a laboratory confirmed case associated with
none of the symptoms described above.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 258 (five-year median = 160; see
Figure 29). Fifty–three cases were probable; the rest were confirmed. The
incidence rate was 2 per 100,000. CDC only counted 204 confirmed cases for
Illinois for 2006.
• Age - Mean age for all 2006 cases was 35 years. Age distribution of cases is
shown in Figure 30.
• Gender – Forty-seven percent were male.
• Race/ethnicity – Eighty-two percent were white, 11 percent were African
American, and 6 percent were other races; 11 percent were Hispanic.
• Seasonal variation - Cases peaked in July through September (Figure 31).
• Clinical – Eight cases were reported to be asymptomatic. Symptoms included
diarrhea (95 percent), fever (45 percent) and vomiting (56 percent); 22 percent
were hospitalized, no cases were fatal.
• Geographic location – The three counties with the highest incidence of
cryptosporidiosis were: Tazewell (58 per 100,000), Carroll (18 per 100,000) and
DeKalb (18 per 100,000). An outbreak was reported in Tazewell County that
resulted in a high incidence rate.
• Reporting – Ninety-two cases were reported by laboratory staff and 83 by
infection control professionals.
• Risk factors –
o Contact with animals – Contact with animals was reported by 103 cases,
including 10 who had contact with cattle.
o Travel - Nineteen persons reported travel outside the United States
including travel to Mexico (six) and China (four). Thirty–two cases traveled
out-of-state but within the United States including ten who traveled to
Wisconsin. Six of the ten cases who traveled to Wisconsin visited the
Wisconsin Dells area, a popular tourist destination that has many
recreational water venues.
o Swimming - Seventy-one of 183 (39 percent) of the cases reported
swimming in chlorinated water. Twenty-nine of 181 (16 percent) reported
swimming in non- chlorinated water.
o Well water exposure - Fifteen of 179 cases (8 percent) reported drinking
private well water;
o Day care contact – Twenty-five of 183 cases (14 percent) reported contact
with a daycare
o Residential facility - Eighteen of 176 cases (10 percent) had contact with a
residential facility.
• Outbreaks: In 2006, three recreational water outbreaks and one community
outbreak occurred in Illinois; three outbreaks are discussed in further detail in the
49
foodborne and waterborne disease outbreak section. In INEDSS, 56 individual
cases were specified as outbreak-related. In the outbreak reports, 65 cases were
listed as linked to waterborne outbreaks. In the community outbreak, 17 persons
in a neighborhood became ill with diarrhea and tested positive for
Cryptosporidium. The source was not identified. All of the children shared pools
and sandboxes.
Summary
The number of reported cases of cryptosporidiosis in 2006 was higher than the
number reported in 2005. Four outbreaks were reported in 2006. The incidence was high
in Tazewell County due to an outbreak in a pool. Most cases in 2006 occurred in the late
summer and early fall. The incidence of reported cryptosporidiosis in Illinois (2 per
100,000) was the same as the preliminary incidence reported by FoodNet.
Number of cases
Figure 29. Cryptosporidiosis Cases in Illinois, 2001-2006
600
483
400
257
121
200
161
102
160
0
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 30. Age Distribution of Cryptosporidiosis Cases in Illinois, 2006
80
60
40
20
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Year
Number of cases
Figure 31. Cryptosporidiosis Cases in Illinois by Month, 2006
150
100
Outbreak
Non-outbreak
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of Onset
50
Sep
Oct
Nov
Dec
Cyclosporiasis
Background
Cyclosporiasis is caused by a protozoal organism, Cyclospora cayatensis.
Clinical illness consists of watery diarrhea and abdominal cramping. Diarrhea is usually
self-limiting but may be prolonged. The median incubation period is seven days.
Transmission to persons is usually through drinking or swimming in contaminated water.
Several international outbreaks have involved consumption of raspberries from
Guatemala. Basil and lettuce also have been implicated in transmission.
In 2006, 137 confirmed cyclosporiasis cases were reported to CDC through
NETSS. Florida reported the most cases in 2006. Of the 10 diseases under active
surveillance in FoodNet sites (illnesses caused by Campylobacter, Cryptosporidium,
Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio
and Yersinia enterocolitica), Cyclospora comprised 41 of 17,252 (0.23 percent) of the
reported infections in preliminary data from 2006. Data from 2006 showed the incidence
rate was 0.09 per 100,000 for Cyclospora and ranged from 0 to 0.3 at the ten FoodNet
sites with preliminary data.
Case definition
Laboratory confirmation is the finding of C. cayatensis oocysts in stool by
microscopic examination or in intestinal fluid or small bowel biopsy specimens; or
demonstration of sporulation or PCR positive in stool, duodenal/jejunal aspirates or small
bowel biopsy specimens. CDC has two case classifications:
Confirmed, symptomatic - laboratory confirmed with clinically compatible illness.
Confirmed, asymptomatic - laboratory confirmed with no symptoms.
Descriptive epidemiology
Number of cases reported in Illinois in 2006 – One case, which was confirmed, was
reported in July from Cook County.
Summary
No outbreaks of cyclosporiasis were reported in Illinois in 2006.
51
Ehrlichiosis
Background
Ehrlichia are bacteria that infect a wide variety of animals and are transmitted by
tick bites. Four Ehrlichia pathogens have been identified in the United States: E.
chaffeensis (causing human monocytic ehrlichiosis (HME)), Anaplasma phagocytophilum
(formerly Ehrlichia phagocytophila) causing human granulocytic anaplasmosis (HGA), E.
canis and E. ewingii. Only one person with E. canis has been reported and the person
was not clinically ill. E. chaffeensis and E. canis mainly invade the monocyte, and the
disease caused by these organisms is termed HME. A. phagocytophilum and E. ewingii
invade mainly the granulocytes and the disease is referred to as granulocytic
ehrlichiosis. Both HGA and HME are zoonotic diseases requiring an arthropod vector
and a mammalian reservoir. A specific history of a tick bite can be elicited in about 68
percent of ehrlichiosis cases.
E. chaffeensis, which causes HME, is transmitted to humans primarily by the lone
star tick, A. americanum. The white-tailed deer is a major host for this tick and acts as a
natural reservoir for E. chaffeensis. Cases of HME are most commonly reported from
Missouri, Oklahoma, Tennessee, Arkansas, and Maryland. The average reported annual
incidence of HME from 2001 to 2002 was 0.7 cases per million population.
The blacklegged tick (Ixodes scapularis) is the vector of A. phagocytophilum
which causes HGA in New England, the North Central United States and Europe. HGA
is more frequently reported than HME with an average incidence of 1.6 cases per million
from 2001 to 2002. States with the highest incidence were Rhode Island, Minnesota,
Connecticut, New York and Maryland.
E. ewingii can be carried by Ambylomma americanum. Cases of human
granulocytic ehrlichiosis caused by E. ewingii have been reported primarily in
immunocompromised patients from Missouri, Oklahoma and Tennessee. Infection may
also occur in dogs.
Both HME and HGA result in similar symptoms: fever, headache and myalgia.
Cases also may have low platelets, low white blood cells and increased liver enzymes.
Rash occurs in approximately one third of HME patients and is rare in patients with HGA
or E. ewingii. In 25 percent of HME cases, respiratory tract involvement occurs, and in
20 percent of cases central nervous system disease occurs. More than 40 percent of
HME cases require hospitalization, and severe complications can include
meningoencephalitis, acute respiratory distress syndrome, toxic shock like syndrome,
renal failure, coagulopathy and multiorgan failure. Serious outcomes can occur with HGA
in persons with impaired immune systems. These Ehrlichia organisms can form clusters
of organisms called morulae, in the white blood cells. The case fatality rate has been
reported as 5 percent in HME and 10 percent in HGE. All symptomatic cases of HGA
should be treated. Fever should be reduced within 48 hours of the initiation of
antimicrobial therapy.
In 2006, 646 HGA, 578 HME and 231 other or unknown types of ehrlichiosis
cases were reported to CDC.
Case definitions
HME
A clinically compatible illness with demonstration of a four-fold change in antibody
titer to E. chaffeensis antigen by IFA in paired serum or positive PCR and confirmation of
E. chaffeensis DNA, or identification of morulae in leukocytes and a positive IFA titer to
52
E. chaffeensis antigen, or immunostaining of E. chaffeensis antigen in a biopsy or
autopsy specimen or positive culture for E. chaffeensis in a clinical specimen.
HGE
A clinically compatible illness with demonstration of demonstration of a four-fold
rise in antibody titer to E. phagocytophila antigen by IFA in paired serum or positive PCR
and confirmation of E. phagocytophila DNA, or identification of morulae in leukocytes
and a positive IFA titer to E. phagocytophila antigen, or immunostaining of E.
phagocytophila antigen in a biopsy or autopsy specimen or positive culture for E.
phagocytophila in a clinical specimen.
Ehrlichiosis, human, other or unspecified agent
A clinically compatible illness with demonstration of a four-fold change in antibody
titer to more than one Ehrlichia species by IFA in paired serum samples, in which a
dominant reactivity cannot be established, or identification of Ehrlichia species other than
E. chaffeensis or E. phagocytophila by PCR, immunostaining or culture.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 32; Twenty-five were HME, six were
HGA and one was of unknown type. All HGA cases were probable. Three HME
cases were confirmed and 22 were probable. At the time when case reports were
due to CDC, Illinois was recorded as reporting 23 HME, six HGA and three other
or unknown ehrlichia cases for Illinois. We will use the Illinois numbers for the
information listed below.
• Age - Cases ranged in age from 11 to 73 years of age (mean= 49 years).
• Gender - Nineteen cases were male and 13 were female.
• Race/ethnicity – All but one case was white; one was Hispanic.
• Geographic distribution –
o Two HGA cases resided in Stephenson County, and one each in Boone,
Jackson, Marion, and Sangamon counties. Four HGA cases were exposed
in-state: two in Stephenson county and one each in Marion and Franklin
counties. Two cases reported tick exposure in Minnesota.
o The HME cases resided in Williamson (four cases), Jackson (three cases),
Perry (two cases), Saline (two cases) and Cook (two cases) counties.
Additionally, one HME case resided in each of Clay, Crawford, Franklin,
Greene, Jasper, Pike, Pope, St. Clair and Union counties. The HME cases
reported exposures in Williamson (three cases), Marion (two cases),
Jackson (two cases) and Cook (two cases) counties. Also, one HME case
reported exposure in each of Pope, Randolph, Franklin, Shelby, Perry,
Union, Saline, Jasper and Greene counties. Four cases reported out-ofstate exposures and one case reported both an in-state and out-of-state
exposure. Two reported unknown exposure locations.
o An ehrlichia case, unknown type, had exposure in Adams County.
• Seasonal variation – Most onsets occurred between June and August (Figure 32).
• Diagnostic testing – The cases of HGA were diagnosed by serologic testing (four
cases), morulae in neutrophils (one case), and smear positive (one case). The
cases of HME were diagnosed with antibody titers (23) and PCR (two).
53
•
•
•
Outcomes – Seventy-two percent of cases were hospitalized. There were no
fatalities.
Reporting – Seventy-two percent of cases were reported by laboratories.
Past incidence - Reported cases of ehrlichiosis in Illinois in past years have been
infrequent : 1992 (none), 1993 (none), 1994 (one), 1995 (four), 1996 (four), 1997
(none), 1998 (two), 1999 (five), 2000 (one), 2001 (seven), 2002 (six), 2003 (nine),
2004 (12) and 2005 (seven).
Summary
Thirty-two ehrlichiosis cases were reported in Illinois in 2006. Sites of tick
exposure for HME cases were primarily in southern Illinois. Most onsets were from June
through August.
Suggested readings
Wormser, G.P. et al. The clinical assessment, treatment, and prevention of Lyme
disease, human granulocytic anaplasmosis, and babesiosis: Clinical practice guidelines
by the Infectious Disease society of America. CID 2006;43:1089-134).
Number of cases
Figure 32. Ehrlichiosis Cases in Illinois by Month, 2006
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
54
Aug
Sep
Oct
Nov
Dec
Shiga-toxin producing E. coli, enterotoxigenic E. coli, enteropathogenic E. coli)
Background
Strains of Escherichia coli that cause diarrhea are classified into pathotypes.
Shiga toxin producing E. coli (STEC) may cause bloody diarrhea and hemolytic uremic
syndrome because they produce Shiga toxins. Enteropathogenic E. coli (EPEC) lack
Shiga toxins and cause nonspecific diarrhea in infants in less-developed countries.
Enterotoxigenic E. coli outbreaks are rarely reported in the United States.
E. coli O157:H7 is one type of STEC and was first recognized as a cause of
human illness and associated with ground beef in 1982. E. coli O157:H7 causes
primarily a diarrheal illness. The infectious dose is thought to be low due to evidence of
person-to-person transmission and recreational water exposure transmission. The
incubation period is from three to eight days with an average of three to four days.
Occasionally, longer incubation periods have been reported. Infection with E. coli
O157:H7 produces symptoms that range from mild to bloody diarrhea and that may
progress to hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura
(TTP); three to five percent of HUS cases are fatal. The term HUS is used to describe
acute renal failure accompanied by non-immune hemolytic anemia and
thrombocytopenia. It occurs most frequently in children less than five years of age after
infection by an agent producing shiga toxin. The illness can involve the central nervous
system (CNS), pancreas, heart and other organs. HUS can be caused by Shigella
dysenteriae type 1 and STEC. The most common cause of HUS in the United States is
E. coli O157:H7.
E. coli O157:H7 is transmitted through consumption of contaminated food or
beverage, person-to-person contact or swimming in contaminated recreational water.
Three large multi-state outbreaks occurred in the fall of 2006 caused by contaminated
spinach and lettuce. In one outbreak, consumption of fresh spinach was linked to E. coli
O157:H7 in a multi-state outbreak. Twenty six states reported 183 cases. Onsets of
illness were from August 19 to September 5. Two Illinois residents were affected.
Another outbreak in California in 2006 was linked to consumption of raw milk.
During 2006, 4,432 STEC cases were reported from 49 states. Of the nationally
reported cases in 2002 in six states, the median interval from onset of symptoms to
PFGE analysis was 15 days for E. coli O157:H7. The median interval from onset of
symptoms to interview was 12 days for E. coli O157:H7.
Of the 10 diseases under active surveillance in the FoodNet sites (illnesses
caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), E. coli
O157:H7 was responsible for 590 of 17,252 (3 percent) of the reported infections in 2006
data. STEC non-O157 were responsible for 209 of 17,252 (1 percent) of the reported
infections. The preliminary incidence rate for E. coli O157:H7 was 1.3 per 100,000 and
ranged from 0.45 to 2.9 per 100,000 at the ten FoodNet sites. The preliminary incidence
rate for STEC non-O157 was 0.5. On STEC non-O157, the following O antigens were
identified: O26 (28 percent), O103 (24 percent) and O111 (15 percent).
CDC recommends that all bloody diarrheal stools be routinely cultured for E. coli
O157:H7. Rapid tests also are available to directly detect shiga toxin in stool specimens.
Specimens testing positive should be cultured to identify which organism (E. coli or
Shigella) produced the shiga toxin. Broth culture media or specimens in which shiga
toxin has been detected should be cultured for E. coli or submitted to the state public
health laboratory for E. coli isolation.
55
Pulsed-field gel electrophoresis (PFGE) is done routinely in Illinois on E. coli
O157:H7 isolates that are submitted to the state laboratory. Epidemiologic investigation
into a cluster of cases should occur after finding a match by two enzyme PFGE. Single
enzyme analysis is insufficient to determine whether isolates and cases are truly related.
Enterotoxigenic E. coli is believed to be a common cause of traveler’s diarrhea.
United States residents who travel overseas may return to the United States with ETEC.
Enterotoxigenic E. coli is not identified by routine stool culture methods.
Prevention measures for enteric E. coli infections include cooking food thoroughly,
prompt refrigeration of foods and separation of cooked and raw foods. Antibiotics are
contraindicated for treatment of E. coli O157:H7 infections; this treatment leads to
release of toxin as bacteria die and increased risk for development of Hemolytic Uremic
syndrome (HUS).
Food safety practices that can decrease risk of E. coli O157:H7 from ground beef
include thawing frozen ground beef in the refrigerator, not at room temperature, and
cooking to a temperature of 160° F. Kitchen items in contact with raw ground beef should
be washed thoroughly before reusing. Consumers must also be responsible for
protecting themselves when in contact with farm animals that may carry STEC.
Case definition
The case definition for a confirmed case of E. coli O157:H7 used in Illinois is a
clinically compatible illness with isolation of E. coli O157:H7 from a stool specimen or E.
coli O157 organisms that are laboratory confirmed as producing shiga toxin. E. coli
isolated in stool from a person with clinically compatible illness that produce shiga toxin
but are not identified as O157 is also reportable as shiga toxin producing E. coli, nonO157. A confirmed case of ETEC is a clinically compatible illness with laboratory
confirmation of enterotoxigenic E. coli from stool. A confirmed case of enteropathogenic
E. coli is a clinically compatible illness with laboratory confirmation of enteropathogenic
E. coli from stool. A probable case of ETEC or enteropathogenic E. coli, or STEC is a
clinically compatible case which is epidemiologically linked to cases but has not been
laboratory confirmed.
Descriptive epidemiology
Shiga-toxin producing E. coli, including E. coli O157:H7
• Number of cases reported in Illinois in 2006 – 125 (five-year median = 143) (see
Figure 33). The incidence for E. coli O157:H7 in 2006 in Illinois was 0.77 cases
per 100,000 population. Of these 125 cases, 96 were identified as E. coli
O157:H7, two were identified as E. coli O157, H antigen unknown. Six were
identified as STEC, non-O157 and 21 were STEC, shiga toxin positive but not
cultured or serotyped. All but two cases were confirmed. CDC counted 104 STEC
cases for Illinois for 2006. The 21 cases of STEC, shiga toxin positive but not
cultured or serotyped were not counted in CDC numbers.
Note: the information below is for E. coli O157:H7 cases only.
• Age - Cases occurred in all age groups (mean = 37 years of age) (Figure 34).
• Gender – Fifty-eight percent were female.
• Race/ethnicity – Eighty eight percent were white, 6 percent were African
American, and 17 percent were other races; 17 percent of cases were Hispanic.
• Seasonal variation - The largest number of cases occurred in the months from
July to September (51 percent of cases) (Figure 35).
56
•
•
•
•
•
Geographic location – The county with the most cases was Cook (44 cases).
Clinical syndrome - Among those with culture-confirmed E. coli O157:H7 for which
symptom information was available, 100 percent reported diarrhea, 82 percent
reported bloody diarrhea, 45 percent reported vomiting and 45 percent reported
fever; six cases (10 percent of patients for whom information was available) had
HUS and no cases had thrombotic thrombocytopenic purpura (TTP). Two cases
reportedly were put on dialysis. Sixty-three of 110 cases (57 percent) were
hospitalized. One case was reported to be fatal.
Reporter – The most common reporters included infection control professionals
(47 percent) and laboratories (38 percent).
Sensitive occupations - There were four cases involving healthcare workers, one
involving a worker at a food service facility, one involving a worker at a daycare,
and two involving workers in other sensitive occupations.
Outbreaks – Two foodborne outbreaks were reported in 2006 (see detailed
description in the “Food and Waterborne Outbreaks” section). In INEDSS, six
cases were reported to be associated with outbreaks.
Risk factors
• Nine of 98 (9 percent) of the cases reported contact with a day care.
• There were two cases attending or residing at a day care and six cases residing
at a residential facility or school.
• Travel –
o Seventeen of 101 cases (17 percent) reported traveling to another state.
 Wisconsin was the most common destination (five cases).
o Four of 96 cases (4 percent) reported traveling to another country. Two
traveled to Mexico, one to India and one to the Dominican Republic.
• Animal Contact
o Thirty-three of 83 cases (40 percent) reported contact with animals. Four
cases had contact with cattle.
• Well Water exposure - One of sixty cases reported drinking well water.
• Recreational Water Exposure
o Six cases of 97 (6 percent) reported swimming in non-chlorinated water.
o Twenty of 91 cases (22 percent) reported swimming in chlorinated water.
• Ground Beef Consumption –
o Forty-seven of 77 cases (61 percent) reported consuming ground beef.
o Eight of these cases reported consuming the ground beef undercooked.
ETEC
•
Number of cases reported in Illinois in 2006 - No cases or outbreaks of ETEC
were reported.
Other types of reportable enteric E. coli
There were no other types of E. coli infections reported in 2006.
Summary
The incidence of infection with E. coli O157:H7 in 2006 was 0.77 cases per
100,000 population, which is lower than what was found in CDC’s FoodNet sites (1.3 per
100,000).
57
Most cases (51 percent) of E. coli O157:H7 occur in the months of July through
September. Bloody diarrhea was reported by 82 percent of case individuals; 10 percent
of patients reportedly had HUS diagnosed by a physician. Fifty-seven percent of cases
were hospitalized. One Illinois case was fatal. Sixty-one percent of cases reported
consuming ground beef.
Suggested readings
Grant, J., et. al., Spinach-associated Escherichia coli O157:H7 outbreak, Utah
and New Mexico, 2006. Emerg Inf Dis [serial on the Internet]. 2008 Oct. Available from
http://www.cdc.gov/EID/content/14/10/1633.htm
Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states.
Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from
http://www.cdc.gov/EID/content/14/2/311
Henderson, H. Direct and indirect zoonotic transmission of shiga toxin-producing
Escherichia coli. JAVMA 2008; 232(6):848-859.
Schneider, J. et. al., Escherichia coli O157:H7 infections in children associated
with raw milk and raw colostrum from cows – California, 2006. MMWR 2008; 57(23):625630.
State and local health departments. Ongoing multistate outbreak of Escherichia
coli serotype O157:H7 infections associated with consumption of fresh spinach-United
States, September 2006. MMWR 2006; 55(38):1045-6.
Number of cases
Figure 33. Shiga-toxin producing E. coli Cases in Illinois, 2001-2006
250
200
150
100
50
0
E. coli O157:H7
173
2001
197
124
2002
122
2003
2004
102
96
41
29
2005
2006
STEC, not further specified
Year
Number of cases
Figure 34. Age Distribution of Escherichia coli O157:H7 Cases in
Illinois, 2006
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
Year
58
30-39 yr
40-49 yr
50-59 yr
>59 yr
Number of cases
Figure 35. Escherichia coli O157:H7 cases in Illinois by Month, 2006
25
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
59
Aug
Sep
Oct
Nov
Dec
Food and Waterborne outbreaks
Background
The surveillance on food-related disease outbreaks (foodborne outbreaks) is
significant in that food can act as a vehicle for transmission of pathogens or their byproducts. Although many foodborne illnesses result in a few days of diarrhea, with
additional symptoms such as fever, vomiting or muscle aches, others can have serious
health effects such as hemolytic uremic syndrome, reactive arthritis, sepsis or Guillain
Barré syndrome.
Foodborne illness can be caused by microorganisms and their toxins, marine
organisms and their toxins, fungi and chemical contaminants. There are three categories
of organisms to consider in discussing the causes of foodborne illness: viruses, bacteria
and parasites. For some viruses, such as hepatitis A or Noroviruses humans are the
only reservoir. Prevention of foodborne illness depends heavily on food handlers and
proper food handling practices. Rotaviruses can occasionally cause foodborne
outbreaks. Shellfish have been associated with hepatitis A virus, calicivirus and Vibrio
spp. outbreaks. The use of gloves for food handlers is often recommended to decrease
transmission of enteric pathogens. A study of glove use did not verify that glove wearers
had less coliform bacteria on the food as compared to food handlers who did not wear
gloves. It has been observed that food handlers wear the same pair of gloves for
extended periods of time. Proper hygiene, such as keeping the environment clean,
avoiding cross contamination, and proper hand washing can help prevent a large
number of food and waterborne outbreaks. CDC estimates that in the 1990’s
approximately 12 percent of foodborne outbreaks were linked to produce items.
Bacteria comprise the largest category of foodborne agents. These include E. coli
O157:H7, Salmonella and Listeria monocytogenes. Parasites like Trichinella in pork,
Anasakis in raw fish or Cyclospora in raspberries also can cause foodborne illness.
Some enteric pathogens, such as Campylobacter, Giardia and Shigella, rarely cause
foodborne outbreaks.
CDC’s Foodborne Disease Active Surveillance Network (FoodNet) is a system to
collect information from seven states and selected counties in three states in the United
States. The network provides stable and accurate national estimates of foodborne
disease occurrences in the country. According to the Preliminary FoodNet Surveillance
Report for 2006, there were a total of 17,252 laboratory-confirmed cases of infection in
their surveillance system. The number of laboratory-confirmed causes was estimated as
follows: Salmonella (15 per 100,000), Campylobacter (13 per 100,000), Shigella (6 per
100,000), Cryptosporidium (2 per 100,000), shiga-toxin producing E. coli (STEC) O157
(1 per 100,000), Yersinia (0.3 per 100,000), Vibrio (0.3 per 100,000), Listeria (0.3 per
100,000), STEC non-O157 (0.5 per 100,000), and Cyclospora (0.1 per 100,000).
In 2006, 18 cryptosporidiosis outbreaks were reported in the United States.
Prevention methods include education on not swimming with diarrhea, not swallowing
pool water, practicing good hygiene and reporting fecal contamination to pool operators
so they can disinfect appropriately. During recognized Cryptosporidium outbreaks,
swimmers should be advised not to swim for two weeks after diarrhea was resolved.
60
A new foodborne and waterborne MS Access database was created at IDPH to
record foodborne and waterborne outbreak information.
Case definition
A foodborne outbreak is an incident in which two or more persons (usually
residing in separate households) experience the onset of a similar, acute illness (usually
gastrointestinal) following ingestion of common food or drink. CDC has established case
definitions for confirmed outbreaks and these are listed under the specific organisms in
this outbreak section.
For foodborne outbreaks, the number ill reflects those who meet a clinical case
definition. For outbreaks where the etiologic agent was suspected and not confirmed,
and the clinical syndrome matched the suspect etiologic agent but no laboratory
confirmation was obtained, the suspect cause is ascribed to this etiologic agent.
IDPH receives reports of potential foodborne outbreaks from many sources.
Outbreak investigations, which are conducted by local health departments, may not
result in a confirmed foodborne outbreak designation and will not be counted in the state
totals. There are a number of reasons for this: lack of information, classification as
person-person transmission or because the symptoms and incubation period do not
clearly indicate a known foodborne pathogen.
Descriptive epidemiology
The number of possible foodborne or waterborne outbreaks reported to IDPH by
local health departments (LHDs) was 85 during 2006. The total for the year was 69
foodborne outbreaks that met the definition of an outbreak and were submitted to the
Centers for Disease Control and Prevention (CDC). Of the 69 foodborne outbreaks, the
etiology was confirmed in 23 foodborne, suspected in 35 outbreaks and unknown in 11
outbreaks. Four of the waterborne outbreaks were confirmed and one was unknown
etiology. Five out of the 74 outbreaks were due to recreational water exposure. (Note:
Drinking water outbreaks were not counted under recreational water outbreaks).
In the year 2006, a total of 1,322 people were reported to have become ill as the
result of the 69 foodborne outbreaks and 135 as a result of the five recreational water
outbreaks.
The mean number of cases ill was 20 per foodborne outbreak and 27 for
waterborne outbreaks; the median number of cases ill was 11 per foodborne outbreak
and 18 for waterborne outbreaks; the number of ill persons per outbreak ranged from 2
to 418 for foodborne and waterborne outbreaks combined. There were 65 persons
hospitalized as a result of the foodborne outbreaks and one hospitalized due to
waterborne outbreaks. There were no fatalities reported due to foodborne or waterborne
outbreaks during the year 2006. Local health jurisdictions reporting foodborne outbreaks
during the year 2006 were: Cook (36), Peoria (four) three each for the counties of
DuPage, Kane, and Vermilion; two each for the counties of Clinton, Livingston, Pike, Will,
and Winnebago; and one each for the counties of Coles, Henry, JoDaviess, Lake,
Macon, Marshall, McLean, and Stephenson; and there were two multi-state foodborne
outbreaks recorded. The waterborne outbreaks were reported from the counties of
Winnebago (two), Lake (one), Logan (one), and Tazewell (one).
61
The 69 reported foodborne outbreaks occurred in the following months: January,
six (9 percent); February, four (6 percent); March, eight (11 percent); April, seven (10
percent); May, six (9 percent); June, four (6 percent); July, six (9 percent); August, seven
(10 percent); September, three (4 percent); October, four (6 percent); November, six (9
percent); and December, eight (11 percent). The recreational water outbreaks were in
January, June, July and August (two). In the 69 foodborne outbreaks reported, the
etiologic agent was determined to be due to bacterial agents (infection or intoxication),
either suspect or confirmed, in 11 (14 percent) (Table 2 and 3). The bacterial pathogens
were as follows: Salmonella spp. (four outbreaks), shiga toxin producing E. coli (two),
Clostridium perfringens toxin (one), Bacillus cereus/ S. aureus toxin (one), B. cereus/C
perfringens toxin (one), S. aureus (one) and Campylobacter (one). The etiologic agent in
41 (59 percent) of the 69 foodborne outbreaks was suspected or confirmed to be caused
by noroviruses. The IDPH laboratories were able to confirm 13 (32 percent) of these viral
outbreaks. The remaining 28 (68 percent) outbreaks were classified as suspect norovirus
outbreaks, largely based on symptoms, incubation and duration in the people who were
affected. Two outbreaks were caused by parasitic agents and one was suspected to be
due to excess calcium. Three of the recreational waterborne outbreaks were caused by
Cryptosporidium, one was caused by Legionella and one had an unknown cause. Pools
and water parks were the sites of exposure for the waterborne outbreaks.
Although thorough investigations were conducted, there was inconclusive
evidence to classify either suspect or confirm etiologic agents in 14 (20 percent) of the
foodborne outbreaks and they were thus classified as etiology unknown.
Food handlers were laboratory tested in nine of the foodborne outbreaks (13
percent). In six (67 percent) of the outbreaks food handlers were found to be positive for
the etiologic agent implicated in the outbreak. Food handlers tested positive for norovirus
in three outbreaks and Salmonella in three outbreaks. In outbreaks involving E. coli
O157:H7, Salmonella serotype Berta, and a parasitic etiology, food handlers were
negative.
Environmental samples were taken in one foodborne outbreak and two
waterborne outbreaks. In the E. coli O157:H7 foodborne outbreak samples were
negative, as well as in the waterborne outbreaks tested for Cryptosporidium and fecal
coliforms.
Through either epidemiology, supportive information or food testing, 19 food or
water items were implicated in outbreaks. In two outbreaks, chicken was implicated
including chicken biryani and buffalo chicken wings. Vegetables were implicated in four
outbreaks (salad in three and spinach in one). There were three outbreaks where pork
was implicated, two outbreaks where beef was implicated (one corned beef and one beef
burrito). Sandwiches were implicated in three outbreaks (one vegetable sandwich, one
club sandwich and one turkey sandwich) and tortillas were implicated in one outbreak.
Ice was implicated in one outbreak. Food items implicated in two other outbreaks
included nachos with dip and peanut butter. The food causing illness in 50 foodborne
outbreaks was unknown.
Food was tested for pathogens in seven (10 percent) of the outbreaks. Positive
foods were found in four (57 percent) of the outbreaks where samples were tested. The
62
responsible pathogens found were E. coli O157:H7, C. perfringens, S. aureus, and
excess calcium.
The site of food preparation in 69 foodborne outbreaks with available information
were: restaurant, 47 (68 percent); caterer, seven (10 percent); banquet facility, two (4
percent); grocery, two (3 percent); private home, two (3 percent); commercial product,
two (3 percent); lake side park, two, (3 percent) and farm, one (1 percent). Four (6
percent) had food preparation done at different sites (home, caterer, restaurant, church,
banquet facility). The five recreational waterborne outbreaks were from entering pools
and water parks.
The site where the food was consumed, with 69 outbreaks were: restaurant, 34
(49 percent); home, 15 (22 percent); banquet facility, five (7 percent); church, three (4
percent); work, seven (10 percent); lake park, two (3 percent) and one each in hospital,
school (1 percent each). In one outbreak (1 percent) food was consumed in multiple
areas. The five recreational waterborne outbreaks had exposure to water at pools or
water parks.
In 28 (39 percent) of the 69 foodborne outbreaks, contributing factors were
known. Contamination was noted as a contributing factor to 24 (86 percent) of the
outbreaks, three outbreaks were related to proliferation/amplification factors (11 percent)
and survival factors was responsible for one outbreak (4 percent).
Summary
In 2006, Illinois recorded 69 foodborne and five waterborne outbreaks compared
to a five-year median of 71. The most common site of food preparation in the reported
outbreaks was restaurants. Improper food handling was the most commonly reported
contributing factors to outbreaks. Both bacterial and viral agents were important causes
of foodborne outbreaks.
In the period 2002-2006, December had an increased number of outbreaks.
Counts of reported foodborne and recreational waterborne outbreaks were highest in
December followed by the month of May in the period, while the lowest counts were
recorded during the months of July, followed by September then October.
Suggested readings
Alden NB et al. Cryptosporidiosis outbreaks associated with recreational water
use – Five states, 2006. MMWR 2007;56(29): 729-32.
63
Table 2. FOODBORNE OUTBREAKS, CASES, AND DEATHS BY ETIOLOGY IN ILLINOIS, 2006
Outbreaks
Cases
#
Etiology
Count
%
Count
%
Bacterial
B. cereus/S. aureus **
1
1
7
7
B. cereus/C. perfringens**
1
1
3
3
Campylobacter
1
1
18
17
Clostridium perfringens
1
1
8
7
Shiga-toxin producing
Escherichia coli (O157:H7)
2
3
6
6
Salmonella
4
6
41
38
Staphylococcus aureus
1
1
23
22
Total Bacterial*
11
14
106
100
Chemicals
Excess calcium
1
1
27
100
Total Chemical
1
1
27
100
Parasitic
Other parasitic
2
3
62
100
Total Parasitic
2
3
62
100
Viral
Norovirus
Total Viral
Confirmed etiology
Unknown etiology
41
41
23
14
59
59
33
20
938
938
Total 2006
69
100
1418
100
100
Deaths
Count
0
0
0
0
---
0
0
0
0
---------
0
0
-----
0
0
-----
0
0
-----
-----
189
#
Confirmed and suspected etiologies
** Suspected intoxication
* Some outbreaks are suspected to be due to bacterial intoxication due to symptoms and incubation period but the
specific agent was not known.
Table 3. FOODBORNE OUTBREAK PATHOGENS BY TESTING STATUS IN ILLINOIS, 2006
Confirmed
Suspected
Etiology
Count
%
Count
%
Bacterial
B. cereus/S. aureus **
0
--1
100
B. cereus/C. perfringens**
0
--1
100
Campylobacter
1
100
0
--Clostridium perfringens
1
100
0
--Shiga-toxin producing
Escherichia coli (O157:H7)
2
100
0
--Salmonella
4
100
0
--Staphylococcus aureus
1
100
0
--Total Bacterial
10
83
2
17
Chemicals
Other chemical (calcium)
Total Chemical
Parasitic
Other parasitic
0
0
-----
1
1
100
100
0
---
2
100
64
%
Unknown
Count
%
Total Parasitic
Viral
Norovirus
Total Viral
Total 2006
0
---
2
100
13
13
32
32
28
28
68
68
23
33
33
47
.
65
12
17
Specific types of foodborne outbreaks
Bacillus cereus
B. cereus causes foodborne illness through intoxication. There are two types of
illness caused by B. cereus, depending on the enterotoxin elaborated by the organism.
In one type, the incubation period is from one to six hours and symptoms last 12 hours
or less. Almost all individuals experience vomiting and about one-third experience
diarrhea. The illness is caused by a preformed enterotoxin. Rice has been associated
with this type of B. cereus in past outbreaks. In the other type, the incubation period
ranges from eight to 16 hours and symptoms last less than 24 hours. Diarrhea is a
prominent feature but vomiting is absent. Foods associated with previous outbreaks
include custards, cereals, and meat or vegetable dishes. The organism multiplies
rapidly at room temperature and the spores can survive boiling.
Case definition
Laboratory confirmation for B. cereus includes isolation of greater than 105
organisms per gram in properly handled food or isolation of the organism from two or
more ill people and not from controls.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - None confirmed. There was
one outbreak that may have been caused by either B. cereus or S. aureus
intoxication as suggested by the clinical presentation and one outbreak in which
the clinical picture suggested either B. cereus or C. perfringens intoxication, both
were not confirmed.
• Bacillus cereus had been identified as the cause of one foodborne outbreak in
2002, five outbreaks in 2003, and two in 2006; there were no outbreaks caused
by B. cereus in 2004 or 2005.
Campylobacter species
Campylobacter infection usually presents as bloody diarrhea, abdominal pain,
nausea, vomiting and fever within two to five days of exposure. However, there are
asymptomatic cases of campylobacteriosis. Cases are often associated with improper
handling of raw poultry or eating raw or undercooked poultry.
Case definition
Campylobacteriosis is diagnosed through isolation of the organism from any
clinical specimen.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - One outbreak was confirmed
and was linked to consumption of raw milk.
o The source of raw milk involved in the Campylobacter jejuni outbreak was
a farm selling raw milk illegally. Eighteen individuals became ill. Raw milk
tested at the farm was negative for Campylobacter. The farm ceased
65
•
selling raw milk following this outbreak.
There was only one outbreak caused by Campylobacter in the previous 5 year
period and that outbreak occurred in 2005.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
Counties of outbreaks
Coles
Food testing
Environmental specimen tested
Confirmed
1
18
18
0
0
1
1
Yes, milk tested negative
none
Clostridium perfringens
Another foodborne intoxication is caused by C. perfringens enterotoxin. Diarrhea
is common but symptoms of vomiting and fever are usually absent. The incubation
period is eight to 16 hours (usually 12 hours). The illness lasts one day or less. Almost
all outbreaks are associated with the inadequate heating or reheating of meats or
gravies, which allows the organism to multiply. The enterotoxin is heat-resistant.
Case definition
There are three ways to establish laboratory confirmation of a C. perfringens
outbreak: 1) isolation of greater than 105 organisms per gram of food that has been
properly handled for testing, 2) demonstration of enterotoxin in the stool of two or more
ills, or 3) isolation of greater than 106 organisms per gram in the stool of two or more ill
persons.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 – One outbreak was confirmed;
one outbreak was suspected to be due to either C. perfringens or B. cereus
without laboratory confirmation.
o An outbreak of confirmed C. perfringens occurred in Chicago. Multiple
employees of a business became ill. Eight people became ill and two stool
samples submitted showed greater than 106 organisms per gram. Illness
began seven to 16 hours after consumption of burritos from a newly
opened establishment in March 2006. The food was prepared at a
restaurant in Wheeling, Illinois and was sold at the Chicago location.
Investigation by the Cook County Food Protection Division (FPD) found
critical violations including operating without a license and improper
temperature for food storage. A citation was issued for closure of the
establishment.
66
•
C. perfringens caused four foodborne outbreaks in 2002, three in 2003, one in
2004, and two in 2006 and there were none in 2005.
Confirmed
1
8
8
0
0
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
March
Counties of outbreaks
Cook
Food testing
1
1
Yes, burritos positive
Shiga toxin producing E. coli (E. coli O157:H7 and others)
Foodborne outbreaks of E. coli O157:H7 have been linked to undercooked
ground beef, apple cider, sprouts and lettuce. Other types of E. coli also can be
pathogenic in humans and cause outbreaks.
A total of 4,432 E. coli O157:H7 cases reported to CDC in 2006. Ground beef is
the most common vehicle in foodborne outbreaks. Produce-associated outbreaks are
also common. Person-to-person outbreaks occur most commonly in day care centers.
Case definition
Laboratory confirmation of an outbreak occurs when E. coli O157:H7 or other
Shiga toxin-producing E. coli is isolated from stool of two or more ill persons or from the
implicated food or water.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - Two confirmed E. coli O157:H7
outbreaks were reported.
o The first outbreak occurred in Cook County in June where two cases of E.
coli O157:H7 were reported by a hospital and both had a history of eating
at the same restaurant in the past week. Human isolates matched by
pulse field gel electrophoresis (PFGE) (pattern O609mlEX2c/EXHX01.0124). Both cases were seen and admitted to the same
hospital. Hospital personnel reported the unusual occurrence of two cases
at the same time. Environmental samples were taken from the restaurant;
all were negative for the pathogen. No fatalities were reported. None of
the restaurant employees reported diarrheal illness and all tested negative
for bacterial pathogens.
o The second outbreak occurred in August and was a multi-state outbreak.
Two of the four persons tested in Illinois matched the outbreak’s PFGE
pattern. Fresh spinach was the food item identified to be the likely source
of the outbreak and spinach samples collected in other states matched the
67
•
PFGE pattern for the outbreak. Spinach eaten by ill persons was tested
and positive for the pathogen. Two people were hospitalized and no
fatalities occurred. Cases were also reported from other states.
There were two STEC outbreaks in each of the following years: 2002, 2003,
2004 and 2006 each; one outbreak was reported in 2005.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
June
August
Counties of outbreaks
Cook
multiple counties
Food tested
Food handlers tested
Environmental specimen tested
Confirmed
2
6
3
2
0
1
1
1
1
1: spinach positive
1: negative
none
Enterotoxigenic E. coli
Enterotoxigenic E. coli is the most common cause of traveler’s diarrhea. People
are the reservoir for this organism. Transmission is usually from consumption of food or
water contaminated with feces from infected persons. The incubation period is 10 to 12
hours if one toxin is present and 24 to 72 hours if both toxins are present. Symptoms
are acute watery diarrhea. Three outbreaks were reported in Illinois from 1998 to 2006.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - None.
Salmonella
Salmonella is the most common causative agent associated with bacterial
foodborne outbreaks. The incubation period for Salmonella is six to 72 hours.
Symptoms may include diarrhea, vomiting, fever and headache.
One of the multi-state outbreaks in 2006 included S. ser. Tennessee associated
with peanut butter. A case-control study linked illness to peanut butter consumption, and
S. ser. Tennessee was found in peanut butter. S. ser. Tennessee is more likely to cause
urinary tract infections than other serotypes. Another outbreak involved cases linked to
fruit salad served in health care institutions in the northestern United States and
Canada. The source of contamination was not identified at the processing plant.
68
Case definition
A laboratory-confirmed outbreak of Salmonella occurs when bacteria are either
cultured from implicated food or Salmonella of the same serotype is cultured from
clinical specimens from two or more ill individuals.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - Four confirmed outbreaks were
reported with 41 people ill (mean = 10 persons ill per outbreak). Outbreaks occurred
in Cook (city of Chicago), Henry, and Macon Counties. One multi-state outbreak had
cases who were residents of multiple counties in Illinois. The Salmonella enterica
serotypes involved in the outbreaks were Enteritidis, Newport, Berta, and
Tennessee. Food handlers were tested in three of the outbreaks and in two
outbreaks food handlers tested positive for Salmonella. Contributing factors were
unknown for three of the four outbreaks except for one where an ill food handler was
a contributory factor. Food testing was performed in two outbreaks and in one
outbreak Salmonella was identified in peanut butter.
o The first Salmonella outbreak of 2006 occurred in late May in Macon County.
Eleven individuals reported being ill after eating in one restaurant on various
dates. Twenty-four possible cases gave specimens for testing and 11 tested
positive for S. ser. Enteritidis. The restaurant voluntarily closed and
environmental samples were taken, all of which were negative for the
pathogen. Five of the 18 employees, including the cook, tested positive for S.
ser. Enteritidis. Food handling employees were restricted from work until
release specimens were negative and the restaurant was able to re-open
after a week. There were three people hospitalized and no fatalities.
o In August, nine individuals reported having symptoms of diarrhea, fever, and
abdominal cramps after eating at a restaurant in Henry County. Incubation
period averaged 60 hours. Seven of the nine human specimens submitted
were positive for S. ser. Newport. Six food handlers were tested and one was
positive for the pathogen. There were three individuals hospitalized and no
fatalities.
o One Salmonella outbreak occurred in October. In this outbreak, the Chicago
Department of Public Health alerted IDPH to an increased number of S. ser.
Berta diagnoses in one month, which is unusual given that two to seven is the
average annual count for this diagnosis in Chicago. Five individuals were
found to have the same PFGE pattern and all reported eating carnitas from
the same grocery store. Food samples from the store, taken one month after
the onset of illness, yielded negative results and eight employee samples
were also negative.
o The last Salmonella outbreak started in August of 2006 with the last case
becoming ill on March of 2007. This outbreak was part of a nationwide
outbreak of S. ser. Tennessee found in Peter Pan and Great Value peanut
butter brands. There were a total of 16 people who were reported ill. Cases
were from multiple counties. Three peanut butter samples in Illinois were
found positive for the Salmonella strain, two of which were submitted by
69
•
cases. Alerts were issued both nationally and statewide on the recall of
peanut butter brands Peter Pan and Great Value with numbers 2111 on their
containers indicating the same manufacturing facility.
In 2002, there were six Salmonella outbreaks, five in 2003, seven in 2004, six in
2005 and four in 2006.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
May
August
October
Counties of outbreaks
Cook
Henry
Macon
Multi-county
Food testing positive
Environmental specimen tested
Contributing factor identified.
Confirmed
4
41
10
13
0
1
2
1
1
1
1
1
1
unknown
Suggested Readings
Landry, L., et al. Salmonella oranienburg infections associated with fruit salad
served in health care facilities – Northeastern United States and Canada, 2006. MMWR
2007; 56(39):1025-8.
Shigella
The Shigella organism is not a common cause of foodborne outbreaks. Instead, it
causes a gastrointestinal illness often transmitted from person-to-person. However,
outbreaks have been associated with consumption of bean dip, lettuce, parsley and
contaminated water. Outbreaks of shigellosis have also been associated with
swimming in contaminated water.
Case definition
The case definition for an outbreak of Shigella is identification of the same
serotype of the bacteria in two or more ill persons.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - None.
70
Staphylococcal food poisoning
One type of foodborne illness, classified as intoxication, is caused by enterotoxinproducing strains of S. aureus. Within 30 minutes to eight hours (usually two to four
hours) after eating contaminated food, a person may experience explosive vomiting and
diarrhea. The duration of illness is usually short - less than 24 hours. Humans are
considered to be the primary source of the organism in foodborne outbreaks. S. aureus
can be found in nasal passages, throat and hair and on the skin of healthy people;
bacteria are present in high numbers in cuts, pustules and abscesses. The enterotoxins
produced by S. aureus are heat stable. The organism may produce toxin in foods and
then die so cultures of foods may be negative and yet the foods contained the
staphylococcal enterotoxin that made people ill. Foodborne outbreaks caused by S.
aureus and those caused by the B. cereus type where vomiting predominates have
similar incubation periods and clinical syndromes.
Case definition
Laboratory confirmation of an outbreak attributable to S. aureus requires
detection of enterotoxin in food or organisms with the same phage type in stools or
vomitus of two or more cases or isolation of greater than 105 organisms per gram in
properly handled food.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 – One suspected outbreak and one
confirmed outbreak were reported. The one suspected outbreak in February was
either S. aureus or B. cereus but the agent was not confirmed.
o In September, 23 people became ill after eating carnitas from a Chicago
restaurant, 13 were considered probable cases due to lack of laboratory
confirmation but consistent symptoms. The median incubation period was
1.75 hours and median illness duration was one day. Left-over foods were
tested and were found to have large quantities of colony forming units per
gram of S. aureus. Stool cultured from individuals yielded negative results.
Improper food storage and temperature were found on second inspection of
the facility. Three people were hospitalized and there were no fatalities.
• Outbreaks: 2002 (one), 2003 (six), 2004 (two), 2005 (none) and 2006 (two).
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
September
Counties of outbreaks
Cook
Environmental specimen tested
Food Testing positive
71
Confirmed
1
23
23
3
0
1
1
None
1, pork carnitas
Chemical agents
This category includes toxins such as ciguatera and scombrotoxin, associated
with fish consumption. Ciguatera toxin poisoning is caused by the ingestion of the toxin
in predatory reef fish, such as barracuda, amberjack and grouper. The toxin is initially
produced by dinoflagellates that are eaten by herbivorous fish, which are then
consumed by the predatory fish. There is a test to detect the toxin in fish. However, the
toxic fish have a normal taste and appearance. The toxin cannot be destroyed by
cooking or freezing. Symptoms of diarrhea and vomiting develop within three to six
hours after consuming contaminated fish. Neurologic symptoms may follow and persist
for weeks or months. These neurologic symptoms include numbness, tingling of the
mouth and extremities, muscle pain and weakness, and reversal of temperature
sensation. There is no diagnostic test or treatment available for humans.
Scombroid fish poisoning occurs after persons have consumed fish that contain
high levels of histamine or other biogenic amines. Histamines accumulate when
bacterial enzymes metabolize histidine in fish. Histamines are not destroyed when fish
are frozen or cooked. This occurs when fish is held at high temperatures. Symptoms
include facial flushing, sweating, rash, a burning or peppery taste in the mouth and
diarrhea. More severe symptoms can occur and result in the need for medical
treatment. Prevention is consistent temperature control of fish at less than 41 F at all
times. Rapid cooling of fish after catch is the best method for prevention of scombroid
fish poisoning. Scombridae include tuna and mackerel which have high levels of free
histidine and are the main fish type linked to scombroid poisoning. Other fish implicated
include mahi mahi, amberjack, bluefish, abalone and sardines. From 1998 to 2002, 118
scombroid fish poisoning outbreaks were reported to CDC.
Case definition
The case definition for ciguatera toxin outbreaks is the demonstration of
ciguatoxin in epidemiologically implicated fish or a clinical syndrome among persons
who have eaten a type of fish previously associated with ciguatera fish poisoning.
The case definition for scombroid toxin outbreaks is demonstration of histamine
in epidemiologically implicated fish or a clinical syndrome among persons who have
eaten a type of fish previously associated with histamine fish poisoning.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 - One suspect outbreak was
reported.
o In January, several Peoria area high schools reported student complaints
of vomiting and abdominal cramps. There were a total of 27 ill students
found who ate tortilla shells from different high school cafeterias. These
tortilla shells were supplied by the same manufacturer to the schools.
They were tested and no viral or bacterial pathogens found, but tortilla
shells were found to have very high levels of calcium propionate, a
preservative. The manufacturer voluntarily recalled the tortilla shells.
72
Chemical
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
Counties of outbreaks
Peoria
Environmental specimen tested
Food Tested
Confirmed
0
0
0
0
0
Suspected*
1
27
27
0
0
0
1
0
1
--none
Excess calcium in tortillas from a manufacturer
Suggested readings
Davis, J. et al. Sombroid fish poisoning associated with tuna steaks – Louisiana
and Tennessee, 2006. MMWR 2007;56(32):817-819.
Parasitic agents
There are a variety of parasitic agents that can cause foodborne or waterborne
outbreaks, for example, Cryptosporidia, Cyclospora and Giardia. The incubation periods
for parasitic agents can be up to 25 days.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 – 2 suspected.
o One outbreak occurred in July in Kane County where attendees of a
catered birthday party reported having diarrhea and abdominal cramps
approximately one week after the event. There were a total of 91 exposed
individuals with 44 out of the 77 interviewed reporting illnesses which
lasted for one to 24 days. Despite testing, no human specimen was found
positive for bacterial pathogens or for Cyclospora. Based on the
incubation period, symptoms, and duration of illness, this outbreak was
suspected to be Cyclospora with the absence of confirmatory laboratory
diagnosis.
o In August, an employee of a business in Kane County called to report that
she became ill with diarrhea and had tested positive for C. difficile and that
approximately 18 of her co-workers have been ill with diarrhea and
abdominal cramps. Upon interview, it was found that an employee event
happened in June and was catered by the same caterer as the other
parasitic outbreak. Eight individuals sought medical evaluation but no
pathogen was isolated. Cases were not tested for Cyclospora. Because of
the incubation period, symptoms, and duration of illness, this was
suspected to be due to a parasitic cause.
73
Parasitic
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
July
Counties of outbreaks
Kane
Food handler positive for pathogen
Environmental specimen tested
Food tested
Confirmed
0
0
0
0
0
Suspected*
2
62
31
0
0
0
2
0
0
None
None
2
None
Viral gastroenteritis
Noroviruses are a common cause of gastroenteritis in the United States.
Estimates are that 23 million people are affected by noroviruses in the United States
each year. There are five genogroups (1-5). Genogroup G1 (Norwalk virus,
Southampton virus and Desert shield virus), G2 (Toronota virus, Mexico virus, Hawaii
virus, Bristol virus, Lordsdale virus, camberwall virus, Snow Mountain agent and
Melksham virus) and genogroup G4 infect humans, genogroup G3 has been found in
cattle and genogroup G5 has been identified in mice. Sapoviruses have only been
identified in humans, especially children.
Noroviruses are transmitted through consumption of contaminated food or water,
directly from person-to-person and from airborne droplets produced during vomiting.
The most common method of spread is via the fecal-oral route. The virus is excreted in
stool and vomitus for up to 10 days. The incubation period and duration of illness
ranges from 24 to 48 hours. Duration of illness ranges from 12 to 60 hours. Virus
shedding peaks 25 to 72 hours after exposure to the virus. Within 48 to 72 hours after
symptom onset, virus concentration in the stool declines below levels detectable by
electron microscopy. An experimental study in Texas found that virus could be found in
stool for a median of 28 days after inoculation using RT-PCR testing. Short-term
immunity occurs after infection. Vomiting, diarrhea, headache and body aches are
commonly reported. A common feature of norovirus outbreaks is secondary
transmission to household members not exposed to the implicated food or water.
Humans are the only known reservoir for these viruses. These viruses cannot
replicate outside the human body and therefore will not multiply in food items.
Characteristics of the virus that facilitate spread include low infectious dose, high
concentration of virus in stool, strain diversity, environmental stability and prolonged
shedding. Failure of an ill food handler to perform proper handwashing may result in
fecal contamination of food. Illness caused by norovirus can be suspected based on
incubation period, duration of illness, symptoms or by identification of the organism in
stool. Noroviruses can survive freezing and temperatures of up to 60 C and can survive
74
chlorine levels up to 10 ppm (that exceeds what is normally present in public water
systems).
In an evaluation of norovirus outbreaks where specimens were submitted to CDC
from July 2000 and July 2004, long-term care facilities, retirement centers and hospitals
were the most likely sites of outbreaks. Person-to-person transmission was most
common followed by foodborne transmission. Genogroup 2 was most common (79
percent) followed by genogroup 1 (19 percent) and sapovirus (2 percent). Serogroup 2
is the prevalent genogroup for noroviruses in outbreaks worldwide.
Outbreaks are not uncommon in closed settings, such as detention facilities,
cruise ships, long-term care facilities and hospitals. An outbreak of norovirus affected
six consecutive cruises on a single ship. Multiple strains of norovirus were identified.
The virus cannot be grown in cell culture; a polymerase chain reaction (PCR) test
is used to diagnose norovirus. Testing for viral gastroenteritis in humans is not useful for
screening individual samples but is useful when multiple samples are available in an
outbreak. Approximately 25 state health department laboratories, including Illinois, can
do the RT-PCR to detect norovirus. Norovirus can be present in stools for up to a week
after illness onset. Immunity is short-lived and appears to be strain specific. Since there
are so many strains, individuals can be repeatedly infected by noroviruses during their
lifetime.
A study of experimental infection found that norovirus was excreted a median of
28 days after inoculation using RT-PCR testing.
Case definition
Several laboratory tests may help to confirm an outbreak related to norovirus.
These include positive results on RT-PCR, visualization of small round structured virus
(SRSV) in electron microscopy of stool from ill individuals, or a fourfold rise in antibody
titer to norovirus seen in acute and convalescent sera in most serum pairs. Multiple
samples are needed from each outbreak to provide sufficient specimens to verify the
causative agent as norovirus. An outbreak is considered confirmed when at least two ill
persons have positive laboratory results.
Descriptive epidemiology
Number of outbreaks reported in Illinois in 2006 – 28 suspected foodborne
outbreaks of viral gastroenteritis, based on clinical syndrome, incubation period and
duration of illness and 13 laboratory confirmed outbreaks were reported. Norovirus
outbreaks affected 938 people who experienced compatible illness (median = 12 ill
persons per outbreak). The average number of ills per outbreak was 23 with a range of
three to 418 ill persons. The median incubation period for the confirmed outbreaks was
33 hours. The 41 norovirus outbreaks occurred in the counties of Cook, (21), DuPage
(3), Vermilion (3), Livingston (2), Peoria (2), Pike (2), Winnebago (2), and one each for
Jo Daviess, Kane, Lake, Marshall, Stephenson, and Will. Genotyping information was
available on 18 outbreaks. Three were G1 (two confirmed and one suspect), 14 were
G2 (nine confirmed and five suspect) and one outbreak involved both G1 and G2.
Eighty-three of the cases sought health care consultation, 10 were hospitalized, and
there were no fatalities. Food handlers were tested for norovirus in four outbreaks and
75
positive food handlers were identified in all four outbreaks. In five of the outbreaks, food
handlers reported illnesses. In seven of the outbreaks, specific food vehicles were
implicated.
<
The first confirmed outbreak occurred in the city of Chicago in January. A
hotel administrator informed the Chicago Department of Health of multiple
gastrointestinal illnesses among attendees of a dinner event in the hotel in
addition to 10 ill employees. Sanitary inspection of the hotel kitchen found
improper temperature and hygienic practices. A total of 418 individuals
met the case definition, 375 primary cases among guests, 35 among
employees, and eight secondary cases. Laboratory testing for norovirus
was positive for 14 case specimens and three food handler specimens.
Twelve cases were identified with norovirus G2 at the IDPH laboratory.
Two were tested at outside laboratories and were not typed.Two people
were hospitalized and there were no fatalities.
<
Another confirmed outbreak occurred in February after the DuPage
County Health Department received a complaint that several persons
attending a retirement party had similar gastrointestinal symptoms as well
as several people from another group attending a rehearsal dinner in the
same hotel. A total of 28 persons reported illness. Primary symptoms
include vomiting and diarrhea. Eight samples from the retirement party
attendees and six from food handlers were tested; two were positive
among patrons and two among food handlers. Four persons were
identified with norovirus G2. Three food items were epidemiologically
linked to illness: smoked mozzarella, tossed salad and ice water. The
latter two items were in common between both groups. One laboratory
confirmed food handler served during the rehearsal dinner and the other
laboratory confirmed food handler helped prepare the salad. There was
also some co-mingling of the two parties since they had activities in close
proximity.
<
A norovirus-confirmed outbreak occurred in March among attendees of a
party where food was catered in Will County. Seventeen of the 22
attendees reported gastrointestinal illnesses such as vomiting and
diarrhea. Three stool specimens were obtained and all were positive for
norovirus G2. Further investigation revealed that one party attendee was
already ill with symptoms of diarrhea. None were hospitalized and there
were no fatalities.
<
Another outbreak in March happened in a restaurant in Jo Daviess County
where 13 of 17 individuals became ill after eating in a restaurant.
Symptoms included vomiting, diarrhea, abdominal cramps, prostration,
fatigue, and body aches with a median incubation period of 29 hours and
illness duration of 50 hours. One patron tested positive for norovirus G2. A
food handler was also found to be positive for the norovirus G2. The ill
food handler, who tested positive, prepared the vegetables and salad.
There was one person hospitalized but there were no fatalities. Salad was
76
<
<
<
<
<
<
linked to the illness.
In April, three laboratory confirmed cases were found from an outbreak
involving several groups of people who ate at a restaurant in Peoria
County. There were a total of 18 patrons and 15 were interviewed. Eleven
of them became ill with abdominal cramps, body aches, diarrhea,
headaches and vomiting. The median incubation period was 39 hours with
a range of 4 to 63 hours. Illnesses lasted from 4 to 50 hours, with a
median of 12 hours. There was no preparation errors found upon
inspection of the restaurant facility. Norovirus G2 was confirmed in this
outbreak.
Another outbreak in April involved a family that gathered in a restaurant for
an Easter meal in Cook County. Eight attendees developed symptoms of
vomiting and diarrhea within a median incubation period of 36 hours. The
duration of illness ranged from 6 to 24 hours with a median of 9 hours.
Two specimens were tested for norovirus and both were found positive for
norovirus G2. It is unknown if food handlers reported illness.
In May, a catered baptism celebration reported illnesses occurring in 16
individuals of the approximately 40 attendees. Symptoms include vomiting
and diarrhea with an incubation period that ranged from 7 to 65 hours
(median of 29.5 hours) and lasted for 12 to 48 hours (median of 42 hours).
Four stool samples all tested positive for norovirus genotype 2. There
were neither hospitalizations nor fatalities. No food handlers reported
illness.
Another outbreak in May happened in Winnebago County. A graduation
party in a private home was attended by 50 to 60 people including a 2year old who had been ill with diarrhea and vomiting prior to the party.
Fourteen guests became ill with the same symptoms. Two specimens
were submitted and were both found to be positive for norovirus genotype
2.
Another May outbreak was reported in Vermilion County. Four of five
individuals reported symptoms of diarrhea, vomiting and abdominal
cramps after eating in a restaurant. Two specimens were found positive
for norovirus genotype 2. The incubation period ranged from 25 to 33
hours (median of 29 hours) and illnesses lasted for 12 to 24 hours
(median of 18 hours). The restaurant owner and a food handler reported
becoming ill several days before the meal but were not tested.
Another outbreak occurred in October in Stephenson County among
several groups of people, including persons attending a wedding
rehearsal, a teacher’s lunch, and in persons who purchased carry out food
from a restaurant. Twenty-three persons were ill with symptoms of
vomiting, diarrhea and abdominal cramps. The incubation period ranged
from 14 to 48 hours with a median of 30 hours and the duration of illness
ranged from 28 to 120 hours with a median of 78 hours. Two specimens
were tested and were positive for norovirus G2. Twenty-three persons
77
<
<
<
were reported to have been ill. Food handler illness status was unknown.
In Livingston County in the month of November, another norovirus
outbreak occurred among 22 individuals who became ill after eating at a
restaurant. Seven specimens were submitted and all of them tested
positive for norovirus. Salad was implicated as the source of illness. One
case was found to have both norovirus G1 and G2. The rest were G1. At
least one food handler tested positive and food handlers reported
illnesses.
Two norovirus outbreaks occurred in December. One outbreak occurred in
Pike County in a group who met and ate buffet food in a restaurant.
Several of the people became ill with symptoms of vomiting, diarrhea and
abdominal cramps. Three ill persons submitted stool specimens and all
were positive for norovirus G1. There were a total of 16 persons ill among
the 24 attendees. The average incubation period was 37 hours and the
average duration of illness was 21 hours. No ill persons were hospitalized.
Contributory factors, including food handler illness, were unknown.
Another December norovirus outbreak occurred in the city of Chicago in
approximately 72 members and guests of a social club who met in a
restaurant and 46 reported becoming ill with diarrhea and/or vomiting. One
case was hospitalized and there were no fatalities. Three of five
specimens submitted were positive for norovirus G2. There were also two
attendees who reported being ill during the event, but whether they
contributed to transmission cannot be established. It is unknown if food
handlers reported illness.
Suggested readings
Atmar, R.L., et. al., Norwalk virus shedding after experimental human
infection. Emerg Inf Dis 2008; 14(10): 1553-7.
Glasscock, S., et al. Multistate outbreak of norovirus gastroenteritis among
attendees at a family reunion-Grant County, West Virginia, October 2006.
78
Norovirus
Confirmed
13
638
49
4
0
Suspected*
28
300
11
6
0
January
February
March
April
May
June
July
August
October
November
December
1
1
2
2
3
0
0
0
1
1
2
2
2
5
5
2
1
1
2
0
4
4
Cook
DuPage
Jo Daviess
Kane
Lake
Livingston
Marshall
Peoria
Pike
Stephenson
Vermillion
Will
Winnebago
3
2
1
0
0
1
0
1
1
1
1
1
1
4
unknown
18
1
0
1
1
1
1
1
1
0
2
0
1
0
1
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
Counties of outbreaks
Food handler positive for pathogen
Environmental specimen tested
Hepatitis A
Foodborne outbreaks of hepatitis A are uncommon. When they do occur they are
often associated with foods contaminated by infected food handlers. Also, contaminated
produce, such as lettuce or strawberries, may also be a source of illness. The
incubation for hepatitis A is 28 to 30 days. The agent can be found in feces before the
onset of illness.
Descriptive epidemiology
Number of hepatitis A outbreaks in 2006 – None.
79
Recreational Water Outbreaks
Background
In 2005 and 2006, Illinois was one of six states reporting at least four waterborne
outbreaks to CDC. Of outbreaks reported to CDC in these two years, 69 percent were
caused by parasites, such as Cryptosporidium. Outbreaks of Cryptosporidium in treated
waters occurs because Cryptosporidium requires extended contact time with chlorine
for inactivation and oocysts can survive for several days in typical swimming pools (1-3
ppm free chlorine). Important prevention messages are to not swim with diarrhea and to
not swallow water while swimming. Chemicals are important to prevent microbial and
algal growth in pools. However, these chemicals can cause illness if applied in the
wrong proportions.
Descriptive epidemiology
Number of recreational waterborne outbreaks in 2006 – Five outbreaks were reported.
The outbreaks occurred in Lake, Logan, Tazewell, and two in Winnebago County. A
total of 135 persons became ill due to recreational water exposure. Three of the
outbreaks were determined to be caused by Cryptosporidium, one Legionella, and one
was caused by an unknown etiology. There was a total of one person hospitalized and
no fatalities for waterborne outbreaks in Illinois in 2006.
• The first waterborne outbreak occurred in January in Logan County. Forty-three
persons became ill with legionellosis after they used the hotel pool and spa
facilities. Improper disinfection of the whirlpool and spa was determined to be the
contributing factor to the outbreak.
• In Winnebago County during the month of June, nine of 12 swimmers in two
swimming classes at a village swimming pool reported burning rashes on
different parts of the body. The teachers of the two classes also reported burning
rashes. The pathogen for this outbreak was unknown but it was determined that
the water was acidic and that chlorine levels were not correct.
• Another waterborne outbreak happened in Tazewell in July where 65 of
approximately 105 exposed persons became ill after swimming in the pool and
water park in the area. Eight specimens were submitted from ill persons and
seven were positive for Cryptosporidium hominis. Water testing on August 11
(illness onsets began on July 29) showed C. parvum from Pool B by PCR at CDC
and Pool A was negative.
• Two waterborne outbreaks happened in August. The site of exposure in both
outbreaks were water parks in the counties of Lake and Winnebago. Eighteen
individuals in Lake and four individuals in Winnebago became ill after being
exposed to the recreational water facilities. In Lake County, two stool specimens
both tested positive for Cryptosporidium, while three of the five stool specimens
tested in Winnebago County tested positive for Cryptosporidium. No water
testing was done in Winnebago County. Water tested negative in Lake County on
August 19 and onsets of illness were August 7.
80
Suggested readings
Yoder, J.S., et. al., Surveillance for waterborne disease and outbreaks
associated with recreational water use and other aquatic facility-associated health
events United States, 2005-2006 and Surveillance for waterborne disease and
outbreaks associated with drinking water and water not intended for drinking – United
States, 2005-2006. MMWR 2008;57(SS-9).
81
Foodborne and waterborne outbreaks in Illinois in 2006.
Exposure
IDPH Log
Number
Onset
Date
City
County
ExpIl/lExp
Symptoms*
Incubation
Hours
Legionnaires
disease and
Pontiac fever
Food Implicated
Agent Implicated
Status
Place of
Preparation
Place Eaten
-
Legionella
Confirmed
Hotel/Motel;
Pool/Spa
Hotel
Unknown
Campylobacter
jejuni
Unknown
Restaurant
Restaurant
Confirmed
Farm
Private home
Norovirus
Suspect
Restaurant
Restaurant
Restaurant
IL2006-34
01/01
Lincoln
Logan
43/900
IL2005-80
01/01
Chicago
Cook
D,V
7
IL2006-1
01/03
Coles
4/5
18/
unknown
D,F,AC
72
IL2006-2
01/15
Forest Park
Cook
5/10
D,V,
37
Unknown
Whole milk,
unpasteurized
Nachos,
unspecified;dips
IL2006-5
01/18
Flanagan
Livingston
15/17
D,V
28-52
Unknown
Norovirus
Suspect
IL2006-3
01/18
Peoria
Peoria
Tortilla,
unspecified
Excess calcium
Suspect
01/30
Chicago
Cook
AC,V
D,F,V, AC,
BA
<1
IL2006-6
32
Unknown
Norovirus G2
Confirmed
IL2006-8
02/10
Arlington Heights
Cook
27/
unknown
418/
unknown
4/
unknown
D,V,AC
31
Unknown
Suspect
IL2006-7
02/10
North Riverside
Cook
7/7
AC,V
0.75
Unknown
Norovirus
B. cereus/ S.
aureus
Restaurant
Commercial
product at
School
Restaurant at
hotel
Banquet
facility
Suspect
Restaurant
Restaurant
IL2006-9
02/12
Danville
Vermilion
7/7
AC,D
32
Norovirus G2
Suspect
Restaurant
IL2006-17
02/24
Carol Stream
DuPage
28/56
D,V
32
Norovirus G2
Confirmed
Banquet
facility at hotel
Private home
banquet
Bacility at
hotel
IL2006-22
03/04
Morton Grove
Cook
16/30
AC,D,V
31
Unknown
Tap water;green
salad;
mozzarella
Sandwich,
vegetablebased
Norovirus
Suspect
Caterer
Hospital
IL2006-25
03/12
Lockport
Will
17/22
AC,D,V
36
Unknown
Norovirus G2
Confirmed
Caterer
Private Home
IL2006-27
03/16
Wilmette
Cook
3/3
AC,F,V
38
Unknown
Norovirus
Suspect
Restaurant
Restaurant
IL2006-38
03/26
Chicago
Cook
3/3
D,V
30
Unknown
Norovirus
Suspect
Restaurant
Restaurant
Norovirus G2
Confirmed
Restaurant
Restaurant
School
Restaurant at
hotel
Banquet
facility
IL2006-35
03/26
Galena
Jo Daviess
13/17
AC,D,V
29
vegetablebased salads
IL2006-43
03/27
Orland Park
Cook
4/15
AC,D,V
31
Unknown
Norovirus
Suspect
Restaurant
Restaurant
Cook
8/
unknown
D
12
burrito, beef
Clostridium
perfringens
Confirmed
Restaurant
workplace
ExpIl/lExp
Symptoms*
Incubation
Hours
Food Implicated
Agent Implicated
Status
Place of
Preparation
Place Eaten
IL2006-33
03/27
Chicago
Exposure
IDPH Log
Number
Onset
Date
City
County
IL2006-39
03/29
Chicago Ridge
Cook
6/11
D,V
13
Unknown
Norovirus
Suspect
Restaurant
Restaurant
IL2006-40
04/01
Dunlap
Peoria
11/15
D,V
39
Unknown
Norovirus
Confirmed
Restaurant
Restaurant
82
IL2006-42
04/02
Peoria
Peoria
39/57
D,V,AC
32
Unknown
Norovirus
Suspect
IL2006-45
04/03
Orland Park
Cook
5/8
D,V
27
Unknown
Norovirus
Suspect
IL2006-47
04/09
Naperville
DuPage
20/36
D,V, AC
31
Unknown
Norovirus
IL2006-50
04/16
Orland Park
Cook
8/12
AC,D,V
36
Unknown
IL2006-61
04/22
Sugar Grove
Kane
23/35
D,V
32
IL2006-65
04/24
Tinley Park
Cook
14/20
D,V
IL2006-66
05/01
Aurora
DuPage
18/24
IL2006-71
05/05
Wheeling
Cook
IL2006-106
05/10
Schaumburg
Cook
IL2006-74
05/14
Roscoe
Winnebago
IL2006-82
05/26
Decatur
Macon
IL2006-77
05/31
Danville
Vermilion
IL2006-81
06/11
Carlyle
IL2006-83
06/15
IL2006-87
Caterer,
Church,
Private home
Church
Restaurant
Suspect
Restaurant
Grocery store,
Private home,
Restaurant
Norovirus G2
Confirmed
Restaurant
Restaurant
Ice
Norovirus
Suspect
Restaurant
Rental Hall
30
Unknown
Norovirus
Suspect
Restaurant
Restaurant
AC,D,V
29
Unknown
Norovirus G2
Confirmed
Restaurant
Private home
5/5
5/
Unknown
D,V,AC
34
Unknown
Norovirus
Suspect
Restaurant
Office
D,V
34
Unknown
Norovirus
Suspect
Restaurant
Restaurant
14/55
11/Unkno
wn
D,V
U
Unknown
Norovirus G2
Confirmed
Private home
Private home
D,AC, F, V
36
Unknown
S. ser. Enteritidis
Confirmed
Restaurant
Restaurant
4/5
AC,D,V
29
Unknown
Norovirus G1
Confirmed
Clinton
25/67
AC,D,V
33
Unknown
Unknown
Unknown
Carlyle
Clinton
19/45
AC,D,V
Unknown
Unknown
Unknown
Restaurant
Food at lake
harbor
Food at lake
harbor
06/16
Pecatonica
Winnebago
9/12
burning rash
U
Immediate
Restaurant
Food at lake
harbor
Food at lake
harbor
-
Unknown
Unknown
Pool
Pool
IL2006-86
06/18
Arlington Heights
Cook
6/10
D,V
30
Unknown
Norovirus
Suspect
Restaurant
Private home
IL2006-88
06/25
Chicago
Cook
2/
unknown
D
120
Unknown
E. coli O157:H7
Confirmed
Restaurant
Workplace,
not cafeteria
ExpIl/lExp
Symptoms*
Incubation
Hours
Food Implicated
Agent Implicated
Status
Place of
Preparation
Place Eaten
D,AC
144
Unknown
Parasitic
Suspect
Caterer
Workplace
Suspect
Banquet
facility,
Restaurant
Restaurant,
banquet
facility
Private home
Exposure
IDPH Log
Number
Onset
Date
City
County
IL2006-98
07/03
Batavia
Kane
IL2006-89
07/08
Glenview
Cook
18/24
12/26
AC,D,V
43
Unknown
83
Norovirus
IL2006-97
07/09
Batavia
Kane
44/77
D
168
potato salad;
pork, beans,
baked
IL2006-91
07/16
Glenview
Cook
3/5
D
14
2/
unknown
D,V
Suspect
Caterer
Club house
Unknown
Parasitic
B. cereus/ C.
perfringens
Suspect
Restaurant
Restaurant
6
Unknown
Unknown
Unknown
Restaurant
Pool with
water park
Private home
Pool with
water park
IL2006-111
07/27
Dolton
Cook
IL2006-101
07/29
Pekin
Tazewell
65/105
D,AC
Unknown
-
Cryptosporidium
Confirmed
IL2006-96
07/30
Chicago
Cook
10/30
D,V
12
Unknown
Unknown
Unknown
IL2007-39
08/01
D
U
Peanut Butter
S. ser.
Tennessee
Confirmed
IL2006-100
08/01
Geneseo
Henry
16/
Unknown
9/
Unknown
Private home,
caterer
Commercial
product,
Private home
D
60
Unknown
S. ser. Newport
Confirmed
Restaurant
Restaurant
IL2006-105
08/06
Peoria
Peoria
39/52
D,V,AC
30
Sandwich, club
Unknown
Unknown
Restaurant
Restaurant &
work
IL2006-103
08/07
Chicago
Cook
3/3
AC,D,V
43
Unknown
Norovirus
Suspect
Restaurant
Restaurant
AC,D
12
sandwich,
turkey
unknown
Unknown
Restaurant
Work
D
120
-
Cryptosporidium
Confirmed
Water park
Water park
D
144
-
Cryptosporidium
Confirmed
Water park
Water park
D,V
36
Unknown
Norovirus
Suspect
Restaurant
Restaurant
D, HUS (1)
36
spinach,
unspecified
E. coli O157:H7
Confirmed
Grocery store
Private home
D,AC
11
Chicken Biryani
Unknown
Unknown
Caterer
Private home
AC,D,V
2
Pork carnitas
S. aureus
Confirmed
Restaurant
Restaurant
Symptoms*
Incubation
Hours
Food Implicated
Agent Implicated
Status
Place of
Preparation
Place Eaten
AC,D, V
9
Unknown
Unknown
Unknown
Restaurant
Restaurant
D,V
30
Unknown
Norovirus G2
Confirmed
Restaurant
Restaurant
D,V
12
Unknown
Unknown
12
unknown
Unknown
Restaurant
Restaurant or
deli
Restaurant
D,V
Unknown
chicken, buffalo
wings
AC,D,F,V
68
Pork carnitas
S. ser. Berta
Confirmed
Grocery store
Private home
Multi-County
Vermilion
2/
Unknown
4/
Unknown
18/
Unknown
5/
Unknown
4/
unknown
IL2006-112
08/14
Evanston
Cook
IL2006-117
08/18
Rockford
Winnebago
IL2006-109
08/18
Gurnee
Lake
IL2006-113
08/23
IL2006-118
08/31
multiple
Multi-County
IL2006-121
09/16
Naperville
Will
IL2006-122
09/24
Chicago
Cook
52/69
23/
Unknown
Private home
Private homes
Exposure
IDPH Log
Number
Onset
Date
City
County
IL2006-124
09/26
Chicago
Cook
ExpIl/lExp
13/
Unknown
IL2006-126
10/07
Freeport
Stephenson
23/
Unknown
IL2006-133
10/21
Chicago
Cook
IL2006-134
10/25
Bloomington
McLean
6/8
6/
Unknown
IL2006-169
10/27
Chicago
Cook
5/
Unknown
84
Private home
IL2006-138
11/03
Gurnee
Lake
8/10
D,V
20-28
Unknown
Norovirus
Suspect
Caterer
Work
IL2006-141
11/12
Norridge
Cook
7/13
D,V,HA
34
Unknown
Norovirus
Suspect
Restaurant
Restaurant
IL2006-154
11/26
Lacon
Marshall
12/41
D,V
33
Unknown
Norovirus
Suspect
Restaurant
Restaurant
IL2006-153
11/26
Milton
Pike
14/32
AC,D,V
33
Unknonw
Norovirus
Suspect
Caterer
Church hall
IL2006-150
11/26
Fairbury
Livingston
22/31
D,V
39
Green salad
Norovirus
Confirmed
Restaurant
Restaurant
IL2006-176
11/28
Worth
Cook
7/8
D,V
8
Unknown
Unknown
Unknown
Restaurant
Restaurant
IL2006-211
12/01
Forest Park
Cook
12/17
AC,D,V
39
Unknown
Norovirus
Suspect
Restaurant
Work
IL2006-172
12/05
Perry
Pike
16/24
D,V
37
Unknown
Norovirus G1
Confirmed
Restaurant
Restaurant
IL2006-175
12/08
Chicago
Cook
46/72
AC,D,V
34
Unknown
Norovirus G2
Confirmed
Restaurant
Restaurant
IL2006-174
12/09
Chicago
Cook
2/10
D,V
2
Unknown
Unknown
Unknown
Restaurant
Restaurant
IL2006-186
12/11
Chicago
Cook
AC,D,V
41
Unknown
Norovirus
Suspect
Restaurant
Church
IL2006-191
12/19
Northbrook
Cook
AC,D,V
13
Unknown
Unknown
Unknown
Restaurant
Restaurant
Norovirus
Suspect
Private
home/Restaur
ant
Private home
Norovirus
Suspect
Restaurant
Restaurant
IL2006-197
12/25
Durand
Winnebago
18/
Unknown
2/
Unknown
7/9
D,V
33
Unknown
Corned beef,
unspecified
IL2006-202
12/30
Forest Park
Cook
22/31
AC,D,V
30
*
BA=body ache, BD=bloody diarrhea, D=diarrhea, F=fever, H=headache, V=vomiting, AC=cramps
85
Giardiasis
Background
Giardia is the most commonly diagnosed intestinal parasite in public health
laboratories. A common intestinal parasite of children, especially those attending day
care, it is spread from person to person through fecal-oral transmission and has a
median incubation period of seven to 10 days. Many infections are asymptomatic and
repeated infections can occur in the same person. There are three species of giardia:
G. lamblia, G. agilis and G. muris. The main human pathogen is G. lamblia. Cysts are
infective immediately upon excretion and can remain viable for months. The infectious
dose is low; as few as 10 cysts can cause infection and excretion can continue for
months. Giardiasis also affects domestic and wild mammals including cats, dogs, cattle,
deer and beavers.
Persons at greatest risk are children in day care facilities, close contacts of
these children, men who have sex with men, backpackers, persons in contact with
infected animals, campers, and persons drinking from shallow wells contaminated by
run-off with the organism. The most commonly identified intestinal parasite in
international travelers is G. lamblia. Giardiasis peaks in late summer and early fall.
Metronidazole is the most frequent treatment for giardiasis in the United States.
Approximately 85 percent of infections can be diagnosed with a single stool
specimen. Diagnosis is made by identification of the parasite in wet mount staining with
trichrome or iron hematoxylin, by direct fluorescent antibody detection, or by enzyme
immunosorbent assay.
Because of its long period of communicability, low infectious dose and
environmental resistance, giardiasis is easily transmitted. Preventive measures should
include practicing good hygiene, avoiding water or food that might be contaminated and
avoiding fecal exposure during sex with infected persons.
In 2006, the CDC received reports on 18,953 Giardia cases.
Case definition
The case definition for giardiasis in Illinois is the presence of diarrhea and the
identification of Giardia trophozoites or cysts in stool, or detection of antigen by the
ELISA antigen test. Carriers are those persons identified with Giardia trophozoites or
cysts in the stool but who have no symptoms of disease.
Descriptive epidemiology
• Number of cases (confirmed and probable) reported in Illinois in 2006 – 695 (fiveyear median = 861); the incidence rate was six per 100,000 population. All but one
of the cases was confirmed. Reported cases decreased from 2005 (See Figure 41).
• Age – The mean age of cases was 42 years. The age group with the highest Giardia
incidence (18 per 100,000) was 1 to 4 years of age (Figure 42).
• Gender – Fifty-eight percent were male.
• Race/ethnicity – Sixty-eight percent were white, 13 percent were African American
and 19 percent were other races; 16 percent were Hispanic.
88
•
•
•
•
•
•
•
Seasonal variation - More cases occurred in August (Figure 43).
Geographic variation - The incidence rate by county ranged from 0 to 27 per
100,000 population by county (Figure 44). Counties with the highest average annual
giardiasis incidence rates per 100,000 population over this period were Jo Daviess
(27 per 100,000), McDonough (21), Scott (18), DeWitt (18) and Kendall (16).
Clinical - Symptoms were diarrhea (90 percent), vomiting (31 percent) and fever (20
percent). Thirteen percent were hospitalized. No fatalities were associated with
cases. At least 63 persons were asymptomatic.
Reporters – Cases were most frequently reported by laboratory staff (64 percent)
and infection control professionals (30 percent).
Employment – Cases reported working in the following sensitive occupations: day
care center (one case), food service (two cases), health care worker (five cases),
residential facility (one case) and other sensitive occupation (six cases).
Risk factors –
o Contact with animals – Contact with animals was reported in 126 of 340
cases (37 percent). Dog contact (86 cases) and cat contact (47 cases) were
most frequent.
o Travel – Sixty cases (17 percent) reported travel to another country. The two
countries most frequently visited were Mexico (11 cases) and India (eight
cases). Fifty (fourteen percent) of cases traveled to another state. Wisconsin
(10 cases) and Florida (six cases) were the most common states visited.
o Swimming – Forty-six of 361 cases (13 percent) of cases reported swimming
in non-chlorinated water, while 55 of 347 cases (16 percent) reported
swimming in chlorinated water.
o Well water exposure - Twenty-nine of 374 cases (8 percent) reported drinking
well water.
o Residential facility - Cases attended or resided in day care centers (11) and
residential facilities (one). Forty-one of 367 cases (11 percent) reported
contact with a day care.
Outbreaks – No foodborne outbreaks were reported in 2006.
Summary
Giardiasis cases decreased in 2006 compared to the previous five-year median
(861). The mean age of cases was 42 years but the highest incidence occurred in those
1 to 4 years of age. More cases occurred in the warmest months of the year.
89
Number of cases
Figure 41. Giardiasis Cases in Illinois, 2001-2006
1000
800
904
871
861
807
772
695
600
400
200
0
2001
2002
2003
2004
2005
2006
Year
Incidence per 100,000
Figure 42. Incidence by Age of Giardiasis Cases in Illinois, 2006
20
15
10
5
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Age in years
Number of cases
Figure 43. Giardiasis Cases in Illinois by Month, 2006
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of onset
90
Aug
Sep
Oct
Nov
Dec
Figure 44. Map of Giardia Incidence by County in Illinois, 2006
91
Hemolytic Uremic Syndrome (HUS)
Hemolytic uremic syndrome (HUS) is characterized by acute hemolytic anemia,
thrombocytopenia and renal insufficiency. Many microbes including Shigella
dysenteriae, Salmonella ser. Typhi, Campylobacter jejuni and E. coli O157:H7 have
been linked to HUS. Bacteria, such as E. coli O157:H7 produce a toxin that can cause
vascular cell damage. The most serious sequelae from infection with Shiga toxinproducing E. coli in people is HUS.
Background
HUS occurs primarily in children younger than 5 years of age after infection by
an organism producing shiga toxin and causing diarrhea. HUS usually occurs within two
to 14 days after onset of diarrhea. Almost half of children with HUS require dialysis. The
illness can involve the central nervous system (CNS), pancreas, heart and other
organs. During 2006, 288 cases of HUS were reported to CDC from 37 states. The
majority of reported cases in 2006 were in patients younger than 5 years of age.
Antibiotic therapy has been identified as a risk factor for HUS development;
therefore, if antibiotic therapy is being considered, it should be withheld for treatment of
patients with diarrhea until a culture confirms that E. coli O157:H7 is not present in a
stool specimen.
Case definition
Laboratory criteria are both acute anemia with microangiopathic changes (i.e.
schistocytes, burr cells or helmet cells) on peripheral blood smear and acute renal injury
evidenced by either hematuria, proteinuria, or elevated creatinine level (i.e. greater than
or equal to 1.0 mg/dL in a child aged less than 13 years or greater than or equal to 1.5
mg/dL in a person aged greater than or equal to 13 years, or greater than or equal to 50
percent increase over baseline).
A probable case is an acute illness diagnosed as HUS or TTP that meets the
laboratory criteria in a patient who does not have a clear history of acute or bloody
diarrhea in the preceding three weeks, or an acute illness diagnosed as HUS or TTP
that a) has onset within three weeks after onset of an acute or bloody diarrhea and b)
meets the laboratory criteria except that microangiopathic changes are not confirmed.
A confirmed case is an acute illness diagnosed as HUS or TTP that both meets
the laboratory criteria and began within three weeks after onset of an episode of acute
or bloody diarrhea.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – Eight cases were reported to CDC.
Cases reported from 2002 to 2006 are show in Figure 45.
• Of the eight cases, three also were listed as an E. coli O157:H7 case. Three
additional cases of physician diagnosed HUS were listed under E. coli O157.
• Age - The eight HUS cases reported to CDC ranged from 1 year to 58 years of age.
92
•
•
•
•
•
Four cases were younger than six years of age.
Sex – Five cases were female and three were male.
Race/ethnicity – All cases were white; none were reported as Hispanic.
Seasonal - Onsets occurred from June to October.
Geographic location – Counties in which cases occurred were Kankakee (two
cases), and one case each from Champaign, Cook, Fayette, Grundy, Kane and Lee
counties.
Clinical – All cases had diarrhea, and six cases reported having bloody diarrhea. All
cases were admitted to the hospital. Five cases needed dialysis. No cases were
fatal.
Summary
Eight cases of HUS were reported by Illinois to CDC in 2006, and an additional
three cases were physician diagnosed. The three not reported were due to confirmed
infection with E. coli O157:H7.
Number of cases
Figure 45. Hemolytic Uremic Syndrome Cases in Illinois, 20012006
10
5
8
5
4
4
3
0
2002
2003
2004
Year
93
2005
2006
Hepatitis A
Background
Hepatitis A virus is transmitted though the fecal-oral route by person-to-person
contact and by contaminated food, water or fomites. HAV infection can spread in
household members, through day care centers, among persons who consume
contaminated or uncooked food handled by infected workers and among men who have
sex with men (MSM). It is one of the most frequently reported vaccine preventable
diseases. The hepatitis A rate in the United States for 2006 was 1.2 per 100,000. Rates
declined 81 percent from 1990 to 2006. There is only one serotype, and immunity after
infection is lifelong. Young children who are frequently asymptomatic when infected
may play an important role in HAV transmission in communities. The incubation period
is 15 to 50 days. Onset of illness with HAV can be abrupt with fever, anorexia, nausea
and abdominal discomfort, followed by jaundice. The disease can vary from one to two
weeks of mild symptoms to a severe illness lasting months. Severity generally
increases with age, and many infections are asymptomatic, especially in young
children. Peak levels of the virus appear in the feces one to two weeks before symptom
onset and diminish rapidly after symptoms appear. Serologic testing for IgM anti-HAV is
required for laboratory confirmation of hepatitis A infection. IgM anti-HAV becomes
detectable five to 10 days after exposure and can persist for up to six months.
Hepatitis A virus infection can be prevented by good personal hygiene,
particularly handwashing, preexposure or postexposure immunization with immune
globulin (IG), and preexposure immunization with HAV vaccine. The administration of
IG for persons exposed to HAV is 85 percent effective in preventing symptomatic HAV
infection if given within two weeks of exposure and may prevent infection entirely if
given soon after exposure. The effect of IG starts within hours of administration and
provides from three to six months of protection. Without prophylaxis the secondary
attack rate ranges from 15 percent to 30 percent in households with an HAV case.
Persons should be considered exposed if they are household contacts of a confirmed
case or persons sharing illicit drugs with a confirmed case. Others with ongoing
personal contact should be provided with prophylaxis. For PEP for non-immune
persons who have been exposed to HAV through sexual or household contact, a single
dose of hepatitis A vaccine or IG should be given. The second dose should be
administered to complete the series. For persons 12 months to 40 years of age,
vaccine is recommended within two weeks of exposure. For persons aged 41 and older
IG is preferred. For contacts who are children younger than 12 months,
immuncompromised persons, persons who have chronic liver disease and persons
contraindicated for vaccine IG should be given. In child care centers, vaccine or IG
should be given to all non-immune staff members and attendees where a case of
hepatitis A is identified in children or employees or if cases are recognized in two or
more households of center attendees. If children with diapers are not present, only
classroom contacts of the hepatitis A case need prophylaxis. If cases occur in three or
more households, prophylaxis should be considered for household members of center
attendees. Other food handlers at the same establishment as a food handler with
hepatitis A should receive prophylaxis. Patrons of a food facility may be recommended
for PEP if during the time when the food handler was likely to be infectious, the food
94
handler both directly handled uncooked or cooked food and had diarrhea or poor
hygiene, and patrons can be treated within two weeks.
In 1995, a hepatitis A vaccine was licensed for individuals older than 2 years of
age. The vaccine was recommended for individuals traveling to areas where there is a
higher endemnicity rate. In 2006, ACIP recommended routine vaccination of all children
aged 12 months or older. Recommendations are for vaccine use in children at 12-23
months. Catch-up vaccination of older children in selected areas and vaccination for
high risk persons (travelers to endemic areas, men who have sex with men and illicit
drug users). Travelers to developing countries are at higher risk for hepatitis A. About
three-quarters of travel-related cases in the United States, are due to travel to Central
or South America. Outbreaks can occur in men who have sex with men communities.
Outbreaks also have occurred in methamphetamine users.
Hepatitis A is typically transmitted from person to person through the fecal-oral
route. Occasionally, foodborne transmission occurs when an HAV-infected food handler
contaminates food that is not later cooked. Food handler associated outbreak
characteristics include the presence of an HAV infected food handler who worked while
infectious and had contact with uncooked food or food after it had been cooked,
secondary cases among other food handlers who ate food contaminated by the index
case and low attack rates in patrons.
The hepatitis A rate in the United States in 2006 was 1.2 cases per 100,000 and
3,579 acute symptomatic cases were reported. The incidence rate was two to four
times higher for Hispanics than non-Hispanics. The most commonly reported risk factor
was international travel, that was reported by 15 percent of cases overall. Most of the
travel was to Mexico and Central and South America. Ten percent of cases reported
sexual and household contact with a case of hepatitis A. For 2006 cases, 73 percent of
infected persons had jaundice, 33 percent were hospitalized and 0.3 percent died with
acute hepatitis A.
Case definition
The CDC case definition for a case of hepatitis A is used in Illinois: an illness
with a discrete onset of symptoms and jaundice or elevated serum aminotransferase
levels, and IgM anti-HAV positive serology.
Descriptive epidemiology
•
•
•
•
Number of cases reported in Illinois in 2006 – 109 (five-year median = 186) (see
Figure 46).
Age - Incidence was highest in 10- to 19-year-olds (1.6 per 100,000) (mean age =
31) followed by the 5- to 9- year-olds (1.5 per 100,000) (see Figure 47). The overall
incidence rate for hepatitis A was 0.9.
Gender – Fifty-five percent of cases were female.
Race/ethnicity - Seventy percent were white, 3 percent African American, and 26
percent other races; 44 percent were Hispanic. Hispanics were overrepresented in
the case population (44 percent) as compared to the Illinois population (12 percent).
95
•
•
•
•
•
•
Employment - Six hepatitis A cases were food handlers.
Seasonal variation - Cases increased in summer months and December (see Figure
48).
Geographic variation – Twenty-three counties reported cases. Cook County
reported the highest number (54 cases).
Risk factors – Risk factors included household contact with a hepatitis A case, nine
(11 percent), travel outside the United States or Canada, 60 (59 percent) and
consumption of raw shellfish, nine (9 percent). Most travelers had visited the area of
Mexico, Central or South America and the Caribbean (41 of 60 cases) especially
Mexico (32 cases). Two individuals reporting being MSM.
Symptoms/outcomes – Seventy-six percent of reported cases were jaundiced.
Forty-two percent of cases were hospitalized. Two deaths were linked to acute
hepatitis A.
Reporters – Forty-five percent of cases were reported by hospitals and 42 percent
were reported by laboratories.
Summary
Hepatitis A is the most commonly reported acute infectious hepatitis in Illinois.
The incidence rate (0.9 per 100,000) was lower than the national incidence (2.7 per
100,000). The number of cases reported in 2006 was lower than the five-year median.
The number of cases has been decreasing dramatically in the last five years. This may
be due to the greater availability of HAV vaccine. The mean age of cases was 31 years,
although the highest incidence (1.6 per 100,000) in 2006 occurred in 10-to-19-yearolds. Hispanics were overrepresented in hepatitis A cases.
Suggested readings
Fiore, A.E., Wasley, A., and Bell, B.P. Prevention of hepatitis A through active or
passive immunization. Recommendations of the Advisory Committee on Immunization
practices (ACIP). 2006; 55(RR-7):1-23.
Novak, R. and Williams, I. Update: Prevention of hepatitis A after exposure to
hepatitis A virus and in international travelers. Updated recommendations of the
Advisory Committee on Immunization Practices (ACIP): 2007; 56(41):1080-84.
Wasley, A., et al. Surveillance for acute viral hepatitis – United States, 2006.
MMWR 57 (SS-2): 1-24.
96
Number of cases
Figure 46 . Hepatitis A Cases in Illinois, 2001-2006
500
400
300
200
100
0
441
262
186
2001
2002
176
2003
130
2004
109
2005
2006
Year
Number of cases
Figure 47. Number of Hepatitis A Cases in Illinois by Age, 2006
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Year
Number of cases
Figure 48. Hepatitis A Cases in Illinois by Month, 2006
25
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
97
Aug
Sep
Oct
Nov
Dec
Hepatitis B
Background
Hepatitis B virus is a vaccine-preventable bloodborne and sexually transmitted
virus. It is acquired by percutaneous and mucosal exposure to blood or body fluids from
an infected person. Men who have sex with men (MSM) are at increased risk for
hepatitis B. Approximately 35 percent of cases of acute hepatitis B occur in people who
report no recognized risk factor. The most commonly reported risk factors for
transmission in the United States are high-risk sexual activity and injection drug use.
The incubation period is 45 to 180 days (average 60 to 90 days). Positivity for HBeAg is
linked to an increased risk of hepatocellular carcinoma.
Fewer than half of acute hepatitis B cases will have jaundice (less than 10
percent of children, and 30 percent to 50 percent of adults). The onset is usually
insidious with anorexia, nausea, vomiting, abdominal discomfort, jaundice, occasional
arthralgias and rash. Chronic HBV infection is found in about 0.5 percent of adults in
North America. An estimated 15 percent to 25 percent of persons with chronic hepatitis
B will progress to cirrhosis or hepatocellular carcinoma.
A vaccine became available in 1982. In Illinois, hepatitis B vaccination in children
was mandated in 1997. CDC also recommends vaccination for MSMs, certain travelers,
injection drug users, heterosexuals with multiple sex partners or with sexually
transmitted diseases, clients or staff in developmentally disabled institutions, health
care workers with blood contact, some immigrants, hemodialysis patients, household
contacts and sexual partners of hepatitis B virus carriers and male prisoners. During
2006, 4,713 acute hepatitis B cases were reported to CDC from across the United
States.
In the United States there has been an 81 percent decrease in hepatitis B since
1990. In 2006, the overall rate of acute hepatitis B was 1.6 per 100,000. The rate was
highest in those aged 25 to 44 years of age (3.1 per 100,000) and the lowest in children
younger than 15 years of age (0.02 per 100,000). At least one-third of cases reported at
least one sexual risk factors (sexual contact with a person with known hepatitis B,
multiple sexual partners or men who have sex with men). Intravenous drug use was
reported by 16 percent of persons. Seventy percent were jaundiced, 40 percent were
hospitalized and 0.8 percent died. The rate in males was 1.8 times higher than in
females. The rate in African Americans was also higher than other races.
In a 2003 study, 75 percent of health care workers were vaccinated against
hepatitis B.
In a study of hepatitis B integration and vaccination in six STD clinics in the
United States, DuPage County had the highest hepatitis B vaccination rate of 56 per
100 client visits in 2002. The overall median rate of completion of the hepatitis B
vaccination series in the six clinics was 31 percent.
Case definition
The CDC case definition is used as the surveillance case definition for hepatitis
B in Illinois: a clinical illness with a discrete onset of symptoms and jaundice or elevated
98
serum aminotransferase levels, and laboratory confirmation. Laboratory confirmation
consists of IgM anti-HBc-positive (if done), or HbsAg-positive, and IgM anti-HAVnegative (if done).
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 132 confirmed acute cases (five-year
median = 130) (see Figure 49). The overall one-year incidence rate of reported
acute hepatitis B in Illinois was 1.06 cases per 100,000 population. In INEDSS, 131
confirmed acute cases are recorded for 2006 so this number will be used for the
information provided below.
• Age – Cases ranged in age from 17 to 74 years of age (mean age = 41 years)
(Figure 50).
• Gender – Sixty-eight percent were male.
• Race/ethnicity – Fifty-two percent of cases were African American, 33 percent were
white and 7 percent were Asian; 13 percent were Hispanic.
• Geographic location – Cases were reported from 21 counties. Counties with the
most cases included Cook (74 cases), St Clair (nine), Kane (six), Lake (six) and
Peoria (six).
• Seasonal trend – Cases were distributed in all months of the year.
• Symptoms/outcomes - Sixty percent of cases were hospitalized. One case was fatal.
• Reporters – Sixty-two percent of cases were reported by hospital personnel,
excluding the hospital laboratory. Thirty-six percent of cases were reported by
private or hospital laboratories.
Summary
There were 131 confirmed acute hepatitis B cases reported in Illinois in 2006.
Sixty percent were hospitalized and one case was reported to be fatal. There was a
higher number of males reported with hepatitis B than females.
Suggested readings
Harris, J.L. et. al. Hepatitis B vaccination in six STD clinics in the United States
committed to integrating viral hepatitis prevention services. Pub Health Reports
2007;122:42-7.
Wasley, A., et al. Surveillance for acute viral hepatitis – United States, 2006.
MMWR 57 (SS-2): 1-24.
99
Number of cases
Figure 49. Hepatitis B Cases in Illinois, 2001-2006
250
200
150
100
50
0
218
185
130
2001
2002
130
111
2003
2004
132
2005
2006
Year
Number of cases
Figure 50. Age Distribution of Hepatitis B Cases in Illinois, 2006
40
30
20
10
0
<1 yr
1-4 yr
5- 9 yr
1 0-19 yr
20-29 yr
Yea r
100
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Hepatitis C, Acute
Background
Hepatitis C virus (HCV), an RNA virus, is the most common chronic bloodborne
infection in the United States. There are at least six distinct genotypes of HCV; types 1a
and 1b are most common in the United States. It is estimated that 1.8 percent of United
States residents have been infected with HCV. The incubation period for HCV ranges
from two weeks to six months, most commonly six to nine weeks. Many individuals are
asymptomatic and only a small proportion become jaundiced. Forty percent of infected
adults are symptomatic, and 85 percent of adults with acute hepatitis C develop
persistent infection. Acute hepatitis C is uncommon.
The most efficient route of transmission is by direct percutaneous exposure (e.g.,
blood or blood product transfusion, organ or tissue transplants, and sharing of
contaminated needles between injection drug users [IDUs]). Low efficiencies of
transmission occur from sexual and household exposure to an infected contact.
Transmission of HCV has been reported from patient to health care worker. The
majority of HCV cases are in IDUs. The virus has been shown to be transmitted by the
use of shared drug preparation equipment such as drug cookers and filtration cotton. In
the United States, injection drug use accounts for 60 percent of HCV infection, sexual
contact (20 percent) and other exposures (household, perinatal and occupational) for
10 percent. Ten percent of cases have no identified risk factor. The rate of transmission
after needle-stick injury from a known infected person is less than 10 percent. The
prevalence of HCV in non-injection drug users in a study in Italy was 20 percent.
Routine screening for HCV infection is recommended only for persons who have
a history of ever injecting drugs, recipients of clotting factor concentrates prior to 1987,
recipients of blood transfusions or solid-organ transplants prior to July 1992, and
chronic hemodialysis patients. Screening is also recommended for sex partners of
HCV-infected persons, infants 12 months or older who were born to HCV-infected
women, and health care workers after accidental needle-sticks or mucosal exposure to
anti-HCV-positive blood. There is no vaccine or effective post-exposure prophylaxis to
prevent HCV infection.
Diagnostic tests for HCV infection include serologic assays for antibodies and
molecular tests for viral particles. Screening tests for HCV include enzyme
immunoassays (EIAs) to measure anti-HCV antibody. While these tests are highly
sensitive, they do not distinguish between acute, chronic or resolved infections. Falsepositive results are common, resulting in the need for supplementary testing. Diagnostic
testing for HCV should include use of both an enzyme immunoassay (EIA) and
supplemental or confirmatory testing with a more specific assay such as the
recombinant immunoblot (RIBA, Chiron Corporation). RIBA results are reported as
positive, indeterminate or negative. It is not as sensitive as the EIA and should not be
used for screening.
In the United States, 802 acute hepatitis C cases were reported to CDC (0.3 per
100,000). The most common risk factor reported was intravenous drug use reported by
54 percent. In 2006, 66 percent of persons reported jaundice, 41 percent were
101
hospitalized and 0.2 percent died.
Case definition
The CDC case definition, which is used in Illinois, is a discrete onset of
symptoms with either jaundice or liver enzymes (ALT or AST) greater than 2.5 x upper
limit of normal and negative serology for acute hepatitis A and hepatitis B and positive
for HCV antibody confirmed by a supplemental test (or simply positive for HCV by the
supplemental test).
Descriptive epidemiology
• Number of cases in Illinois in 2006 – Thirteen cases of acute hepatitis C were
reported.
• Age – Acute hepatitis C cases ranged from 10 to 68 years of age (mean age = 44).
• Gender – Forty-six percent of acute hepatitis C cases were male.
• Race/ethnicity - For acute hepatitis C cases, 83 percent of cases were white, and 17
percent were African American; 11 percent were Hispanic.
• Geographic variation – Eleven counties reported cases.
• Reporter – Forty-six percent of cases were reported by hospitals and 31 percent by
laboratories.
• Symptoms/outcomes – Sixty-seven percent of 12 acute hepatitis C cases with
histories were hospitalized, and no cases were fatal.
Summary
Acute hepatitis C is an uncommon disease, only 13 cases were reported in
Illinois in 2006.
Suggested readings
Hahn, J. A. Sex, drugs, and hepatitis C virus. JID 2007; 195:1556-59.
Wasley, A., et al. Surveillance for acute viral hepatitis – United States, 2006.
MMWR 57 (SS-2): 1-24.
102
Hepatitis C, Chronic or Resolved
Background
The World Health Organization estimates that 170 million people worldwide are
infected with HCV. The hepatitis C virus can cause chronic hepatitis, cirrhosis and
hepatocellular carcinoma. Among adults who had acute hepatitis C, 26 percent to 50
percent developed chronic active hepatitis and 3 percent to 26 percent developed
cirrhosis. In a study of transfusion related hepatitis C in the United States from 1968
through 1980, the risk for developing cirrhosis was 17 percent. Heavy alcohol use
increased the risk for developing cirrhosis. Anti-HCV positive persons had a 5- to 50fold higher risk of primary hepatocellular carcinoma compared to anti-HCV negative
patients. These sequelae typically take 20 or more years to develop.
Hepatitis C is the most common indication for liver transplantation in adults and
accounts for about 40 percent of all transplants in the United States. About 50 percent
to 80 percent of patients with pretransplantation viremia develop hepatitis in the liver
graft.
Persons with chronic hepatitis C should not drink alcohol and should be
vaccinated for hepatitis A and hepatitis B. HCV-positive persons should not donate
blood, organs, tissues or semen. There is insufficient data to recommend that infected
persons change sexual practices with steady partners. HCV-positive household
members should not share toothbrushes or razors.
Treatment for hepatitis C may be recommended for persons with elevated serum
alanine aminotransferase (ALT) and tests that indicate the presence of circulating HCV
RNA. HCV RNA levels do not correlate with grade or stage of disease. HCV is divided
into six genotypes. Genotype is a predictor of response to therapy. Genotype 1a and 1b
HCV infection, the most common types in the United States, have a poorer response to
therapy than other types. Response to therapy is higher in those with genotypes 2 and
3.
Descriptive epidemiology
• Number of cases in Illinois in 2006 – There were 6,843 cases of chronic or resolved
hepatitis C reported. Because this is a chronic disease, these cases may have
acquired infection years ago and the number of cases, is just the number of cases
reported in 2006, not necessarily the year of exposure or onset of any illness.
• Age – Chronic or resolved hepatitis C cases ranged from one to 96 years of age
(mean age = 50 years).
• Gender – Sixty-five percent of chronic or resolved hepatitis C cases were male.
• Race/ethnicity - For chronic or resolved hepatitis C cases, 67 percent of cases were
white, 27 percent were African American and 5 percent were other races; 6 percent
were Hispanic.
• Geographic variation – Ninety-seven counties reported cases. The 10 counties
reported the most cases were Cook (2,893), Winnebago (322), Dupage (273), Will
(270), Lake (240), Sangamon (211), St. Clair (177), Kane (162), Peoria (158) and
Macon (133).
103
•
•
•
•
Genotype – Genotype was only available for 198 cases. The most common
genotypes reported were 1b (66 cases), 1a (37), 3a (35), 2b (25) and 1 (14).
Genotypes reported in five or less persons included 2, 3, 4,1c, 2a, 2a/2c and mixed.
Risk factors - For chronic or resolved hepatitis C, risk factors included history of
injection drug use (41 percent of 2,267 cases), cocaine or other street drugs (46
percent of 2,246 cases), tattoos or piercings (49 percent of 2,208 cases), blood
exposures (13 percent of 2,225), contact with other hepatitis C cases (16 percent of
1,824) and blood transfusions (25 percent of 2,082).
Symptoms/outcomes – Twenty-two percent of 3,166 chronic or resolved hepatitis C
cases with histories were hospitalized, and 11 cases were fatal.
Reporter – Fifty-six percent of cases were reported by private laboratories, 25
percent by hospital personnel other than laboratory personnel and 12 percent by
hospital laboratory personnel.
104
Histoplasmosis
Background
Histoplasmosis is a systemic fungal disease caused by Histoplasma capsulatum.
Transmission occurs through inhalation of the organism. The incubation period ranges
from three to 17 days. Signs and symptoms of histoplasmosis include fever, headache,
muscle aches, cough and chest pain. Patients who have underlying lung disease may
develop chronic lung disease after H. capsulatum infection. Bird and bat droppings are
beneficial to the growth of the organism. Diagnosis of infection can be through culture
or serology. The M precipitin alone indicates active or past infection. The H precipitin
indicates active disease or recent infection.
Histoplasmosis can be a severe infection in persons with HIV or other
immunocompromising conditions. Approximately 5 percent of persons with AIDS who
live in endemic areas may develop histoplasmosis, which frequently disseminates.
Case definition
Histoplasmosis is not a nationally notifiable disease. The case definition for
histoplasmosis in Illinois is either:
1)
Isolation of the organism from a clinical specimen in patients with acute
onset of flu-like symptoms, or
2)
In patients with flu-like symptoms, hilar adenopathy and/or patchy
infiltrates found on chest radiograph, if done, and at least one of the
following:
a.
M or H precipitin bands positive by immunodiffusion
b.
A four-fold rise between acute and convalescent complement
fixation (CF) titers
c.
A single CF titer of >1:32
d.
Demonstration of histoplasma polysaccharide antigen by
radioimmunoassay (RIA) in blood or urine, or demonstration of
organisms by silver staining blood specimens or biopsy material
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 112 (five-year median = 72) (see
Figure 62). At least 31 (28 percent) of these cases were in immunocompromised
persons; therefore, it is not possible to determine whether they represent new
infections or reactivation of previous infections.
• Sex – Sixty-four percent of cases were male.
• Age - Mean age was 42 years (Figure 63).
• Race/ethnicity – Seventy-three percent were white, 21 percent were African
Americans, and 5 percent were other races; 10 percent were Hispanic.
• Disease type – Twenty cases had disease described as disseminated
histoplasmosis. Of 67 cases with chest x-ray results, 58 (88 percent) had
abnormalities.
• Symptoms – Symptoms included difficulty breathing (71 percent); fever (65 percent);
105
•
•
•
•
•
•
•
cough (64 percent), night sweats (51 percent) and chest pain (46 percent). Twentyseven percent reported being current smokers.
Diagnosis – All cases were reported as confirmed; Twenty-seven cases (24 percent)
were confirmed by culture. Cultures were positive from blood (eight cases), lymph
node (four), lung (three), bone or bone marrow (two), bronchial wash (two), other
(five) and unknown (two). Two cases had positive smears from the following sources
blood (one) and lung (one). Thirty-seven cases were M band positive by
immunodiffusion. Forty cases had complement fixation titers of at least 1:32; 17 of
these also were positive by M band testing. For 29 cases, more than one diagnostic
method was positive.
Seasonal variation - No seasonal trend was identified (See Figure 64).
Geographic variation - The three counties reporting the most cases were Cook (29
cases), Sangamon (10 cases) and Champaign (eight cases).
Reports of exposure to the following (not reported for all cases) - Dirt arenas (21
percent), construction (20 percent), excavation (11 percent), potting soil (10
percent), plowing (9 percent), bird raising (9 percent) and caves (4 percent).
Outcomes – Sixty-seven (63 percent) of cases were hospitalized; three cases were
fatal.
Outbreaks - One outbreak was reported in 2006. Two Chicago residents traveled
out-of-state and acquired histoplasmosis.
Reporting- Fifty-three percent of cases were reported by hospital personnel and 37
percent by laboratories.
Summary
In 2006, 112 cases were reported as compared to 72 in 2005. One small
outbreak was reported. The most common symptoms were difficulty breathing, fever
and cough.
Number of
cases
Figure 62. Histoplasmosis Cases in Illinois, 2001-2006
120
100
80
60
40
20
0
98
59
2001
72
57
2002
112
96
2003
2004
Year
106
2005
2006
Number of cases
Figure 64. Histoplasmosis Cases in Illinois by Month, 2006
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of onset
107
Aug
Sep
Oct
Nov
Dec
Legionellosis
Background
Legionella spp are linked with warm water and biofilms that support the growth
and survival of the organism. There are 48 species of Legionella and several serotypes.
L. pneumophila serotype 1 is responsible for most lower respiratory tract infections.
However, 19 other Legionella species have been documented as human pathogens
based on isolation from clinical material. The two major clinical manifestations of
infection with Legionella bacteria are Legionnaires’ disease (legionellosis) and Pontiac
fever. Legionellosis may be epidemic or sporadic, nosocomial or community acquired.
Approximately 4 percent of persons with community acquired pneumonia test positive
by Legionella urinary antigen. The incubation period is two to 10 days (average five to
six days). For Pontiac fever, it is five to 66 hours (average 24-48 hours). Initial
symptoms of both are anorexia, myalgia and headache often followed by a
nonproductive cough and diarrhea. Patients with legionellosis clinically have pneumonia
and abnormal chest radiographs.
Legionellosis most often occurs in those who are immunocompromised due to
disease or aging. Risk factors are underlying medical conditions such as human
immunodeficiency virus, organ transplantation, renal dialysis, diabetes, chronic
obstructive pulmonary disease, cancer, immunosuppressive medication or smoking.
Pontiac fever is an acute, febrile illness with a high attack rate, short incubation period
and rapid recovery. Most cases are sporadic (not associated with a known outbreak).
Outbreaks have been associated with aerosol producing devices such as whirlpool
spas, showers, humidifiers, respiratory care equipment, evaporative condensers, air
conditioners, grocery store mist machines and cooling towers and have occurred in
industrial settings. Approximately 20 percent of all Legionnaires’ disease cases are
outbreak related. Many are thought to be associated with potable water systems in
hotels or whirlpool spas in hotels or on board cruise ships.
Legionella urine antigen testing and culture of respiratory secretions are useful
for diagnostic testing. The urine antigen test provides rapid diagnosis for L.
pneumophila serogroup 1 but will not provide an isolate to compare to clinical and
environmental isolates gathered during outbreak investigations. Testing for Legionella
species is not performed by the IDPH laboratory. Most test results among reported
cases are from hospital or commercial laboratories.
In 2006, 2,834 cases of legionellosis were reported to CDC from state health
departments. CDC has a travel-associated Legionella surveillance e-mail address used
by state health departments to report cases of Legionella that have traveled outside
their state. From 1990 through 2005, the number of cases reported to CDC by year
ranged from 1,094 to 2,291. The incidence increased over time especially in the
northeastern United States and the South. Cases were most commonly reported in
those 45 to 64 years of age. Rates in males exceeded females.
Case definition
A confirmed case in Illinois is one that meets the CDC case definition, i.e., a
108
clinically compatible illness with laboratory confirmation of disease by 1) isolation of
Legionella from lung tissue, respiratory secretions, pleural fluid, blood or other normally
sterile sites; or 2) demonstration of a fourfold or greater rise in the reciprocal indirect
fluorescence (IF) antibody titer to greater than or equal to 128 against L. pneumophila
serogroup 1 between paired acute and convalescent phase serum specimens; or 3)
demonstration of L. pneumophila serogroup 1 in lung tissue, respiratory secretions, or
pleural fluid by direct fluorescent antibody (FA); or 4) demonstration of L. pneumophila
serogroup 1 antigens in urine by radioimmunoassay (RIA) or enzyme-linked
immunoassay (ELISA).
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 127 (five-year median = 150) (Figure
65). All were confirmed. CDC reported 128 cases for Illinois for 2006, but there are
127 in the Department records. The information below is based on 127 cases.
• Age – Seventy-six percent of cases were greater than 50 years of age (see Figure
66).
• Gender – Eighty (63 percent) cases were male.
• Race/ethnicity – Four percent reported Hispanic ethnicity.
• Seasonal - An increase in cases occurred in September (Figure 67).
• Geographic distribution – Thirty counties reported cases. Fifty-eight cases (46
percent) resided in Cook County.
• Risk factors - Twenty percent of 95 cases stayed in a hotel overnight in the two
weeks prior to onset. At least one underlying health problem among diabetes (six),
cancer (four), transplant (one), corticosteroid therapy (seven), smoking (15) or
multiple underlying conditions (17) was reported by 50 of 64 (78 percent) cases with
that information; percent reported no underlying health problems. No cases were
reported to be nosocomial. Nine persons were reported as residing in a residential
facility.
• Diagnosis - Cases were diagnosed through urine antigen only (89), serology only
(13), culture of respiratory secretions or blood only (six), direct fluorescent antibody
of respiratory secretions only (three), multiple methods (five) or unknown (11).
• Outcomes - Hospitalization was required for 113 of 119 cases with information
available; Ninety-six cases reported X-ray confirmed pneumonia, two did not have
pneumonia and for 29 cases the information was not available at the time of this
report; Five fatalities were reported among cases.
• Reporting – The majority of cases with information available (76 percent) were
reported by infection control professionals.
• Outbreaks – One outbreak was reported in 2006. Two confirmed cases of
Legionella were linked to a hotel with a pool and spa in Logan County. After an
investigation which involved contacting hotel guests, a total of three cases of
Legionnaires’ disease and 40 cases of Pontiac fever were identified. Five cases
were laboratory confirmed. A hotel pool and spa were culture positive for Legionella
pneumophila and L. macearchernii. Persons spending time in the pool area were at
higher risk for disease.
109
Summary
In 2006, there was a decrease in cases of legionellosis, as compared to the fiveyear median. Seventy-eight percent of 64 cases had pre-existing medical conditions.
There was one outbreak of legionellosis in 2006.
Suggested readings
Ng, Victoria, et. al. Our evolving understanding of legionellosis epidemiology:
Learning to count. CID 2008:47:600-2.
Neil, K. and Berkelman, R. Increasing incidence of legionellosis in the United
States, 1990-2005: Changing epidemiologic trends. CID 2008;47:591-9.
Smith, P., et al. Surveillance for travel-associated Legionnaires disease – United
States, 2005-2006.
Number of cases
Figure 65. Legionellosis Cases in Illinois, 2001-2006
127
150
100
66
55
50
50
28
24
0
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 66. Age Distribution of Legionellosis Cases in Illinois, 2006
80
60
40
20
0
<30
30-39
40-49
Age groups
110
50-59
>59
Number of cases
Figure 67. Legionellosis Cases in Illinois by Month, 2006
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of onset
111
Aug
Sep
Oct
Nov
Dec
Lyme Disease
Background
Lyme disease is a tickborne zoonotic disease caused by the bacterium Borrelia
burgdorferi sensu lato. The reservoir is the black-legged tick (Ixodes scapularis),
commonly called the deer tick. Human disease is thought to be primarily caused by
nymphal tick bites, usually in late spring or summer. Babesiosis and ehrlichiosis also
are transmitted by the same tick. In the Midwest, wild rodents and other animals
maintain the transmission cycle. Deer are the preferred host of the adult tick.
Laboratory studies indicate ticks must be attached for at least 24 hours for
transmission to humans to occur. Experiments in animals have shown that most often
the tick must feed at least 48 hours before the risk of transmission becomes
substantial.
Lyme disease is characterized by a rash-like skin lesion called erythema migrans
(EM) that may be followed by cardiac, neurologic and/or rheumatologic involvement.
The incubation period for EM ranges from three to 32 days (mean: seven to 10 days)
after tick exposure; it is present in 80 percent to 90 percent of case patients. Erythema
migrans may be characterized by a homogenous rash rather than a target appearance
because of early presentation for treatment. EM is the most common clinical
manifestation of Lyme disease. Early manifestations include fever, headache, fatigue,
migratory arthralgias and possibly lymphadenopathy. It can take approximately two to
four weeks or longer for antibodies to be detected by blood tests, so these tests are not
required for patients diagnosed with EM in the public health surveillance case definition.
There were 19,931 cases of Lyme disease (6.75 per 100,000) reported in 2006
in the United States, mainly from the Northeast, mid-Atlantic and north-central regions
of the country. Ten states - Connecticut, Delaware, Maryland, Massachusetts,
Minnesota, New Jersey, New York, Pennsylvania, Rhode Island and Wisconsin accounted for 93 percent of all cases reported. The majority of cases had onset in
June, July or August. Manifestations of Lyme disease included erythema migrans (69
percent), arthritis (32 percent), neurologic (12 percent) and AV block (0.8 percent). A
study of electronic laboratory reporting from 2001 through 2004 in New Jersey showed
that only 29 percent of Lyme disease electronic lab reports were confirmed as Lyme
disease upon investigation.
Effective prevention measures include personal protective measures (tick
checks, repellents) and decreasing tick exposure. The Infectious Disease Society of
America has advanced the recommendation that antimicrobial prophylaxis can be
offered after a recognized tick bite if the following conditions are true: 1) the attached
tick is identified as Ixodes and was attached for greater than 36 hours, 2) prophylaxis
can be started within two hours of when the tick was removed, 3) the tick infection rate
in the area is 20 percent or greater and 4) doxycycline is not contraindicated. In a casecontrol study of Lyme disease in Connecticut from 2000 to 2003, cases were less likely
to report using protective clothing outdoors and to use tick repellents on their skin or
clothes.
B. burgdorferi infected Ixodes scapularis ticks were recovered from Cook,
112
Dupage and Lake Counties and one-third of ticks were infected.
Case definition
The surveillance case definition for Lyme disease in Illinois is the CDC definition:
1) erythema migrans, or 2) at least one late manifestation (musculoskeletal system,
nervous system or cardiovascular system) and supportive laboratory evidence of
infection or laboratory confirmation, i.e., isolation of B. burgdorferi from a clinical
specimen, or demonstration of diagnostic immunoglobulin M or immunoglobulin G
antibodies to B. burgdorferi in serum or cerebrospinal fluid (CSF). A two-test approach
using a sensitive enzyme immunoassay or immunofluorescence antibody followed by
Western blot is required by the Department for confirmation of non-EM cases.
Descriptive epidemiology
During 2006, increased numbers of cases occurred in the northeastern part of
Illinois where deer ticks became established. Wisconsin also reported an increase in
Lyme disease cases in 2006.
•
•
•
•
•
•
•
•
•
•
Number of cases reported in Illinois in 2006 – One hundred and ten (five-year
median = 71) (See Figure 68) cases were reported. All cases were confirmed. The
incidence was 0.9 per 100,000.
Age - Cases ranged in age from 1 to 18 years of age (mean= 38) (Figure 69).
Gender – Sixty-four percent were male.
Race/ethnicity – Of the cases for which race is known, 94 (99 percent) were white;
two cases identified themselves as Hispanic.
Seasonal distribution – Lyme disease case onsets were most common from May
through July (Figure 70).
Geographic distribution - Forty-one cases reported a single Illinois county as an
exposure locale are mapped in Figure 71. One case reported multiple Illinois
counties as exposure sites. Four cases reported Illinois plus another state as
exposure sites. Sixty cases reported non-Illinois exposure locations including
Wisconsin (48), Michigan (four), Pennsylvania (two), Massachusetts (one),
Minnesota (one), Maryland (one), multiple states (three) and Poland (one). For two
cases no exposure location could be identified. Twenty counties reported residents
with Lyme disease. The top four counties reporting residents with Lyme disease
included Cook County (35 cases), Jo Daviess (21 cases), Will (11) and DuPage
(10).
Tick Distribution – A map of Illinois with the distribution of known Ixodes scapularis
(the vector for Lyme disease) is provided (Figure 72).
Symptoms - Qualifying manifestations were EM (90, 82 percent), rheumatologic
signs () and neurologic signs such as Bell’s palsy (). Six percent of cases were
hospitalized; no deaths were reported in cases.
Reporting – The three top reporters of Lyme disease cases were laboratory staff (53
percent), clinics (21 percent) and infection control professionals (20 percent).
Tick exposure – Twenty-five of 63 (40 percent) of cases reported a tick bite before
113
•
illness onset. Ninety-three of 94 (99 percent) of cases reported being in a tick
habitat. The three most common sites of tick exposure habitat were own property
(28 cases), campgrounds (23 cases) and parks and nature preserves (18 cases).
Past incidence - In Illinois, reported Lyme cases for previous years are as follows:
1991 (51), 1992 (41), 1993 (19), 1994 (24), 1995 (18), 1996 (10), 1997 (13), 1998
(14), 1999 (17), 2000 (35), 2001(32) and 2002 (47), 2003 (71), 2004 (87) and 2005
(127).
Summary
For the cases reported in Illinois residents during 2006, EM was the most
common qualifying manifestation for Lyme disease. The number of cases peaked in the
summer months. The incidence in Illinois (1.0 per 100,000) is much lower than the
national average (6.7 per 100,000) for 2006. The number of reported cases of Lyme
disease decreased for the first time since 1996.
Suggested readings
Anon. Effect of electronic laboratory reporting on the burden of Lyme disease
surveillance – New Jersey, 2001-2006. MMWR 2008; 57(2): 42-45.
Auwaerter, P.G. Point: Antibiotic therapy is not the answer for patients with
persisting symptoms attributable to Lyme disease. CID 2007;45:143-8.
Bacon, R.M., et. al. Surveillance for Lyme disease – United States, 1992-2006.
MMWR 2008; 57(SS-10).1-9.
Jobe, D.A. et al. Lyme disease in urban areas, Chicago (letter). EID [serial on the
internet] 2007. Available from http://www.cdc.gov/EID/ content/ 13111/1799.htm.
Vazquez, M., et al. Effectiveness of personal protective measures to prevent
Lyme disease. Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from
http://www.cdc.gov/EID/content/14/2/210.htm.
Wormser, G.P. et al. The clinical assessment, treatment, and prevention of Lyme
disease, human granulocytic anaplasmosis, and babesiosis: Clinical practice guidelines
by the Infectious Disease society of America. CID 2006;43:1089-134.
Number of cases
Figure 68. Lyme Disease Cases in Illinois, 2001-2006
127
150
100
50
110
87
71
47
32
0
2001
2002
2003
2004
Year
114
2005
2006
Number of cases
Figure 69. Age Distribution of Lyme Cases in Illinois, 2006
30
20
10
0
<11 yr
11-20 yr
21-30 yr
31-40 yr
41-50 yr
51-60 yr
>60 yr
Age groups
Number of cases
Figure 70. Lyme Disease Cases in Illinois by Month, 2006
50
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of onset
115
Aug
Sep
Oct
Nov
Dec
Figure 71. Illinois Map of Reported Exposure Location of Lyme disease Cases by
County, 2006
Jo DaviessStephensonWinnebago McHenry Lake
21
0
0
0
0
Boone
Carroll
0
Ogle
1
7
Kane
DeKalb
0 DuPage
0
1
Whiteside
Lee
0
Cook
0
Kendall
1
0
Will
Rock Island
Bureau
2
Henry
La Salle
0
0
Grundy
0
0
Mercer
3
Kankakee
0
Stark
0
Marshall
0
0
Knox
Livingston
0
HendersonWarren
Iroquois
0
Peoria
Woodford
0
0
2
0
Ford
McDonough
Tazewell
0
0
McLean
Fulton
0
Hancock
0
0
0
Mason
ChampaignVermilion
De Witt
Schuyler
0
Logan
0
0
0
0
0
Piatt
Menard
Adams Brown
Cass
0
0
0
0
0
Macon
Douglas
0
Sangamon
Morgan
Edgar
0
0
Moultrie
Pike Scott 0
0
0
Christian
0
0
Coles
0
0
Shelby
Greene
Clark
0
Cumberland 0
0
Macoupin
Montgomery
0
Calhoun
0
0
Jersey
1
Effingham
Jasper Crawford
Fayette
0
0
0
0
0
Bond
Madison
0
Clay
0
RichlandLawrence
0
1
0
Clinton Marion
1
0
St. Clair
Wabash
Wayne
0
0
Washington
0
Jefferson
Monroe
Edwards
0
0
0
0
White
Randolph Perry
0
Franklin
0
0
0
Jackson
SalineGallatin
0
0
Williamson 0
0
Hardin
UnionJohnson
0
Pope
0
0
0
AlexanderPulaski Massac
0
0
0
116
Figure 72. Tick Distribution Map
117
Malaria
Background
Malaria is a very important global parasitic disease. It is endemic in more than
100 countries. The incubation period may range from seven days to 10 months.
Symptoms of malaria include fever, headache, muscle aches, fatigue, diarrhea, and
vomiting. Four species of Plasmodium (P. vivax, P. falciparum, P. malariae and P.
ovale) cause disease in people. P. vivax malaria is the most common form. P.
falciparum is the most common species in tropical areas and causes the most malaria
deaths. The majority of malaria-endemic countries are in sub-Saharan Africa,
Southeast Asia and Latin America. More than 90 percent of the incidence of malaria in
the world occurs in sub-Saharan Africa and two-thirds of the remaining cases occur in
India, Myanmar, Afghanistan, Vietnam and Colombia. The highest risk of malaria is for
travelers to sub-Saharan Africa, Papua New Guinea and the Solomon Islands. About
90 percent of P. falciparum infections are acquired in Africa. More than 70 percent of P.
vivax infections are due to exposures in Asia or Latin America. In a study of travelers
visiting GeoSentinel clinics in the world from 1997 through 2006, the most common
diagnosis for persons returning to their homes with fever was malaria. P. falciparum was
diagnosed in 66 percent of persons with malaria. The most common destinations were
Oceania, the Pacific Islands or sub-Saharan Africa.
Immunity lasts less than two years once a person leaves an endemic area.
Many persons who travel back to their home country assume they are immune.
Identification of the malaria species is important because treatment can differ. For
example, disease caused by P. falciparum has a more serious prognosis and must be
treated differently. Untreated P. falciparum can progress to coma, renal failure,
pulmonary edema and death. The majority of fatal cases in the United States are due to
not using correct chemoprophylaxis, incorrect initial chemotherapy and delays in
malarial diagnosis. One of the most important diagnoses to consider in recent travelers
with fever is malaria. Imported malaria cases occur in Illinois when someone with the
disease immigrates to the United States or when someone who travels overseas uses
inadequate chemoprophylaxis. Persons traveling to malarious areas should take
recommended chemoprophylaxis regimens and use appropriate personal protective
measures against mosquito bites (using mosquito nets at night when accommodations
do not protect against mosquitos and repellents). The risk of malaria depends on
geographic location of travel, urban versus rural stay, type of accommodations, duration
of stay, time of the year, activities, elevation and compliance with preventive measures.
In the United States, malaria is transmitted predominantly by the bite of an infective
female anopheline mosquito to travelers while overseas. Other less common methods
include infected blood products, congenital transmission or local mosquito borne
transmission. Malarial infection or relapse during pregnancy results in risk to the
mother and fetus, including maternal anemia, spontaneous abortion, perinatal mortality,
118
low birth weight, and prematurity. Symptoms in newborns include fever, poor appetite,
irritability, and lethargy and can mimic sepsis.
Malaria should be considered in the differential diagnosis of illness in persons
with 1) fever and a history of travel to areas where malaria is endemic, including
immigrants, 2) fever of unknown origin, regardless of travel history, or in 3) ill neonates
and young infants with fever and mothers who have immigrated or traveled to areas
where malaria is endemic.
The majority of malaria infections in Illinois are caused by travel to areas with
ongoing transmission. In 2006, 1,564 malaria cases were reported in the United States
including six fatal cases. The species of malaria identified in these cases was
falciparum (39 percent), vivax (18 percent), malariae (3 percent) and ovale (3 percent).
In 37 percent of cases the species was unknown. Malaria is transmitted in parts of
Africa, Asia, the Middle East, Central and South America, the island of Hispaniola and
Oceania. The majority of infections in the United States were acquired in Africa (70
percent), followed by Asia (18 percent) and the Americas (10 percent). Sixty-seven
percent of cases had taken no chemoprophylaxis. Among foreign residents for whom
the purpose of travel was known, 58 percent were recent immigrants or refugees and
17 percent were visiting friends or relatives in the United States.
Case definition
Illinois uses the CDC case definition. A confirmed case is a person
(symptomatic or asymptomatic) with an episode of microscopically confirmed malaria
parasitemia diagnosed in the United States, regardless of whether the person
experienced previous episodes of malaria while outside the country.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 83 (five-year median = 61) (see
Figure 73). All were confirmed cases.
• Age – Sixty-nine percent of cases occurred in persons from 10 to 39 years of
age. The mean age of cases was 35 (Figure 74).
• Sex – Sixty percent of cases were male.
• Race/ethnicity - Fifty-two percent were African American, 20 percent were white,
18 percent were Asian and 10 percent were other races; no cases were reported
to be of Hispanic ethnicity. There were significantly higher proportions of African
Americans with malaria compared to their presence in the Illinois population and
significantly lower proportions of whites and Hispanics with malaria compared to
the Illinois population.
• Geographic location – Malaria cases were reported from residents of 17
counties. The majority were reported from Cook County (58 percent).
• Seasonal variation - Cases of malaria were reported in greater numbers in the
summer (Figure 75).
• Speciation - The malaria species identified in the reported cases were P.
falciparum (39 cases, 51 percent of cases with known species), P. vivax (30
119
cases, 39 percent), P. malariae (five cases, 6 percent), P. ovale (one case, 1
percent) and unknown (seven cases) (Figure 76).
•
•
•
•
•
Treatment/outcomes - Fifty-one of 79 cases (64 percent) were hospitalized. No
cases are known to have been fatal.
Risk factors - The major risk factor for infection is travel outside the United
States. Specific information was available for 78 of the 2006 cases. The Asian
countries reported by cases as travel destinations were India (19 cases), Papua
New Guinea (one case) and Nepal (one case). In Africa, the following travel
destinations were reported for 50 cases: Nigeria (26 cases), Ghana (six cases),
Cameroon (four cases), Uganda (three cases), Tanzania (one case), Liberia
(one case), Madagascar (one case), Ethiopia (one case), Guinea (one case) and
multiple African countries (six cases). One case reported a travel destination of
South America (Brazil). Two cases reported travel to the Middle East (one case
to Iraq and one to Afghanistan). Two cases reported travel destinations in
multiple continents. For four persons the location of travel was unknown. For one
person, travel history was unknown.
Of the 26 cases reporting travel to Nigeria, 20 were infected with P. falciparum,
two with P. malariae, and none with P.vivax. Three cases were not speciated. Of
the six cases who visited Ghana, five had P. falciparum and one case had
P.vivax. Of the 19 cases reporting travel to India, 17 were infected with P. vivax,
one with P. falciparum and one with multiple species.
Cases provided the following reasons for travel overseas: visiting friends or
relatives overseas (26), refugee or adoption (nine), visiting United States (six),
missionary work (five), business (four), tourism (three), military (two), other
(eight), and unknown (19).
Reporting – Sixty-three of 83 cases (73 percent) were reported by hospitals and
18 (22 percent) were reported by laboratories.
Summary
There were 83 reported cases of imported malaria identified in Illinois in 2006,
the sixth highest number of cases among the states. This was higher than the annual
median (61 cases) for the previous five years.
African Americans and Asians made up a higher proportion of persons with
malaria than in the Illinois population. Laboratories should forward blood smears to the
Department’s laboratory for verification of species. Laboratories should be thorough in
identifying the species of this parasite because treatment differs by species (e.g., P.
vivax and P. ovale require additional treatment with primaquine to prevent relapses)
and simultaneous infection with more than one species does occur.
Suggested readings
Wilson, M.E. et al. Fever in returned travelers: Results from the GeoSentinel
surveillance network. CID 2007;44:1560-8.
120
Number of cases
Figure 73. Malaria Cases in Illinois, 2001-2006
100
80
60
40
20
0
83
74
71
61
47
46
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 74. Age Distribution of Malaria Cases in Illinois, 2006
25
20
15
10
5
0
<1 yr
1-4 yr
5- 9 yr
1 0-19 yr
20-29 yr
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Age Group
Number of cases
Figure 75. Malaria Cases in Illinois by Month, 2006
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
121
Aug
Sep
Oct
Nov
Dec
Figure 76. Species of Malaria
Identified, Illinois, 2006
P. ovale
1%
P. malariae
6%
F. vivax
40%
P.
falciparum
53%
122
Measles
Background
Measles is a highly communicable viral disease with humans as the only natural
host for the infection. Transmission most commonly occurs through airborne spread or
through direct contact with nasal or throat secretions of infected people. The incubation
period is about 10 days, but varies from seven to 18 days. Infected individuals show
fever, conjunctivitis, coryza, cough and Koplik’s spots on the buccal mucosa, along with
a rash that appears on the third to seventh day. The disease can be prevented by
proper immunizations. A two-dose vaccination schedule is recommended in the United
States, one at 12 to 15 months and one at school entry (4 to 6 years) or by 11 to 12
years. Sustaining high levels of vaccination is important to limit indigenous spread of
measles from cases imported into the United States.
Nationally, there were 55 cases reported to CDC; 95 percent were imported and
additional cases occurred from these imported cases. For three cases, the source was
classified as unknown because no link to importation could be identified. Four
outbreaks occurred, all from imported sources. More than half (31 of 55) of cases were
in adults aged 20 to 39 years of age.
Case definition
A confirmed case in Illinois is one that meets the CDC definition, i.e., a case that
is laboratory confirmed, or that meets the clinical case definition and is
epidemiologically linked to a confirmed case. Laboratory confirmation consists of 1)
isolation of measles virus from a clinical specimen, or 2) significant rise in measles
antibody level by any standard serologic assay, or 3) positive serologic test for measles
IgM antibody. The clinical case definition is an illness characterized by a generalized
rash lasting at least three days, and a temperature of at least 101° F, and a cough or
coryza or conjunctivitis.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – None.
Summary
No cases of measles were reported.
123
Number of cases
Figure 74. Measles Cases in Illinois, 2001-2006
4
3
3
2
2
1
1
1
1
0
0
2001
2002
2003
2004
Year
124
2005
2006
Mumps
Background
Mumps is transmitted by droplet spread and by direct contact with the saliva of
an infected person. The incubation period is 12 to 25 days. This viral disease is
characterized by fever and swelling and tenderness of salivary glands lasting two or
more days and without other apparent cause. Orchitis may occur in males and
oophoritis in females. Winter and spring are the times of increased occurrence.
Vaccination can prevent mumps. To prevent mumps a two-dose MMR vaccination
series for all children (first dose at 12-15 months, second dose at 4-6 years of age).
Two doses are recommended for school and college entry unless there is other
evidence of immunity. In 2006, 6,584 mumps cases were reported to CDC. In 2006, the
largest mumps outbreak in more than 20 years occurred in the United States. The
majority of cases were reported from March to May. Eight-four percent of cases were
from six Midwestern states (Illinois, Iowa, Kansas, Nebraska, South Dakota and
Wisconsin). Eighteen to 24 year olds were most affected.
Case definition
A confirmed case in Illinois is one that meets the CDC case definition: a clinically
compatible illness that is laboratory confirmed, or that meets the clinical case definition
and is epidemiologically linked to a confirmed or probable case. A laboratory-confirmed
case does not need to meet the clinical case definition. The laboratory confirmation
may consist of 1) isolation of mumps virus from a clinical specimen, or 2) a significant
rise in mumps antibody level by a standard serologic assay, or 3) a positive serologic
test for mumps IgM antibody. The clinical case definition is an illness with acute onset
of unilateral or bilateral tender, self-limiting swelling of the parotid or other salivary
gland, lasting more than two days, and without other apparent cause.
Descriptive epidemiology
•
•
•
•
•
•
•
•
•
Number of cases reported in Illinois in 2006 - 798 (five-year median = 10) (Figure
75). Of the 798 cases, 336 were confirmed and 462 were probable.
Age - Mean age was 26 years (range was 1 years to 89 years).
Gender - Sixty-six percent were female.
Race/ethnicity – Eighty-six percent were white, 9 percent were African American, 3
percent were Asian and 2 percent were other races. Ten percent reported Hispanic
ethnicity.
Geographic distribution - Cases resided in 67 counties.
Seasonal variation - Cases occurred from January through December.
Clinical syndrome – The mean duration of parotitis was seven days.
Outcome – Complications included orchitis (19), meningitis (two) and deafness
(one). Twenty-six cases were admitted to the hospital. No fatalities were reported.
Immunization status – Of the cases reported in Illinois, 42 percent could
125
•
demonstrate history of two doses of mumps-containing vaccine, 14 percent had
one dose and an additional 11 percent had an unsubstantiated number of mumpscontaining doses. Of the 34 percent with no or unknown vaccination status, 17
percent were old enough to be unsure if they had actually ever been vaccinated, 11
percent had no history of vaccination and 6 percent failed to answer the question.
Outbreaks – An outbreak began in Iowa and involved many other states, including
Illinois. Mumps viral isolates from six states were genotype G. The greatest number
of onsets occurred in April, with more than 50 cases each week during April. Case
rates were highest among students attending the following colleges: Southern
Illinois University-Carbondale (22 percent), Augustana (11 percent), Northern
Illinois University (10 percent), University of Illinois-Chicago and Loras (each 8
percent). The primary control strategy in the Illinois student population (95 percent
coverage) was early diagnosis and exclusion for nine days following onset of
parotitis or other significant symptoms associated with mumps.
Summary
The mean age of the 798 reported mumps cases in 2006 was 26 years. There
was a very large increase in mumps cases in the state over previous years due to a
multi-state outbreak. A large outbreak started in Iowa college students, which spilled
over into Illinois. Almost half reported being appropriately immunized.
Suggested readings
Gershman, K. et. Al. Update: Multistate outbreak of mumps – United States,
January 1-May 2, 2006. MMWR 2006;55(20):559-63.
Number of cases
Figure 77 . Mumps Cases in Illinois, 2001-2006
1000
800
600
400
200
0
798
21
18
2001
10
8
2002
2003
2004
Year
126
10
2005
2006
Number of cases
Figure 72. Age Distribution of Mumps Cases in Illinois, 2006
250
200
150
100
50
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Age Group
Number of cases
Figure 73. Mumps Cases in Illinois by Month, 2006
300
200
100
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
127
Aug
Sep
Oct
Nov
Dec
Orf
Background
Orf is a viral cutaneous disease transmitted to human through contact with sheep
or goats that are infected. The incubation period is usually three to six days. Skin
lesions, usually on the face, arms or hands may last three to six weeks. Diagnosis is
through typical lesions and history of contact with infected sheep or goats. Laboratory
confirmation by polymerase chain reaction can be performed at the Centers for Disease
Control and Prevention.
Case Definition
A confirmed case is a clinically compatible history with a history of sheep or goat
contact and positive test for the orf virus at the Centers for Disease Control and
Prevention.
Case description
In July 2006, a 17-year-old female presented to her health care provider in
northwest Illinois with a lesion of three weeks duration on the tip of her right middle
finger. The provider lanced the lesion and recovered a small amount of blood, sutured
it, placed the patient on azithromycin and referred her to a dermatologist. The patient
presented to the dermatologist the next day. The lesion was 1.3 cm in diameter and
had a red center with a white ring and red halo. Due to the appearance of the lesion the
dermatologist suspected orf virus infection. A biopsy of the lesion was sent to the CDC
for laboratory confirmation. An immunohistochemical (IHC) test using an
immunoalkaline phosphatase technique was negative. Real-time PCR was performed
and was positive for pox virus. The patient had been bottle feeding lambs three weeks
prior to the appearance of the lesion. She admitted to letting the lambs nurse on her
fingers. The lambs had not been vaccinated against orf. The lesion resolved within one
month of the initial presentation.
128
Pertussis
Background
Pertussis is a highly infectious respiratory disease and is caused by Bordetella
pertussis and is characterized by a paroxysmal cough that can last several weeks.
Pertussis should be considered in adolescents and adults especially if the cough is
associated with vomiting or gagging or persists more than two weeks. Pertussis in
adults may be missed because symptoms may be atypical, and nasopharyngeal
cultures are rarely positive if taken during the first seven days of illness. Pertussis is
transmitted from person to person via aerosolized droplets from cough or sneeze or by
direct contact with secretions from the respiratory tract of infectious persons. Pertussis
can be highly infectious during the three weeks after onset of illness. The incubation
period is usually seven to 10 days although it can range from six to 20 days.
A resurgence of cases has been reported in the last decade in the United States.
A total of 15,632 pertussis cases (5 per 100,000) were reported to CDC from states in
2005. The likely explanation for the increase are increased circulation of B. pertussis,
waning vaccine-induced immunity among adolescents and adults, increased reporting
and increased use of PCR testing. Of these cases, the incidence was highest (84 per
100,000 population) in infants younger than 6 months of age (too young to have
received three doses of vaccine). Adolescents and adults account for the majority of
cases. Vaccine-induced immunity wanes about five to 10 years after pertussis
vaccination.
For the first week, mild fever, coryza and cough are common. From week one
through six, a paroxysmal cough, inspiratory whoop, and post-tussive vomiting may
occur. From six to 12 weeks, the intensity of cough decreases. Outbreaks are managed
through prompt treatment of patients and antimicrobial prophylaxis of close contacts.
Acellular pertussis vaccines are used in children from 6 weeks to 6 years of age.
Pertussis has increased in adults. Active immunization with five doses of vaccine
at 2, 4, and 6 months of age, at 12 to 15 months and at school entry can prevent this
disease. However, immunity from childhood vaccination decreases beginning five to 15
years after the last pertussis vaccine dose. Vaccination with Tdap vaccine of persons
aged 11 to 64 is recommended. In the national immunization survey, vaccine coverage
rates for greater than or equal to 4 doses of DTaP among children 19 to 35 months of
age in Illinois was 84 percent as compared to 85 percent nationally in 2006.
To confirm the diagnosis of pertussis in symptomatic adults, physicians should
obtain a nasopharyngeal aspirate or swab for B. pertussis culture within two weeks of
cough onset. The lack of fast, sensitive and specific tests makes laboratory diagnosis
difficult. PCR was introduced in 1997. In outbreak settings, positive PCR should be
interpreted in conjunction with epidemiologic investigation, clinical course and
confirmed by culture. A subset of cases should be cultured. Culture is the gold standard
and 100 percent specific. Its sensitivity can be up to 56 percent early in the course of
illness but decreases with delays in specimen collection, in vaccinated patients or
patients treated with antimicrobials. Isolation of the organism can take seven to 14
days.
129
Case definition
The case definition for pertussis in Illinois is a clinically compatible illness that is
laboratory confirmed or epidemiologically linked to a laboratory-confirmed case.
Laboratory confirmation is through culture of B. pertussis from a clinical specimen. A
clinically compatible illness is a cough lasting at least two weeks with one of the
following: paroxysms of coughing, inspiratory whoop or post-tussive vomiting (without
other apparent causes) or greater than two weeks of cough in a person in an outbreak
setting. A confirmed case is defined as a cough illness of any duration in any person
with isolation of B. pertussis or a case that meets the clinical case definition and is
confirmed by polymerase chain reaction or by epidemiologic linkage to a laboratoryconfirmed case. A probable case meets the clinical case definition but is not laboratory
confirmed or epidemiologically linked to a laboratory-confirmed case.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - 588 (five-year median = 321) (Figure
74). There were 358 confirmed and 230 probable cases reported. The one-year
incidence rate for pertussis was 4.7 per 100,000.
• Age - Eighteen percent occurred in those younger than 5 years of age (Figure 75).
In 2006, 32 percent of cases occurred in those older than 19 years of age.
• Gender - Females comprised 56 percent of cases.
• Race/ethnicity - Ninety percent were white, 6 percent were African American, 3
percent were in other races. Seventy-four cases were of unknown race; Twelve
percent reported Hispanic ethnicity.
• Seasonal variation - Cases increased from August to January (Figure 76).
• Outbreaks – There were four specific outbreaks reported in INEDSS including one
in Jo Daviess County, one in McLean County, one in a Chicago school and one in a
Cook County school. An overall increase occurred in the state.
Summary
The number of yearly reported pertussis cases decreased since 2005 in Illinois
but was higher than the five-year median. The highest incidence occurred in those
younger than 1 year of age.
There were 588 pertussis cases reported in Illinois in 2006 including four
outbreaks in three counties involving 75 persons (13 percent of the total reported
cases).
Suggested readings
Counard, C. et. al. Use of mass Tdap vaccination to control an outbreak of
pertussis in a high school-Cook County, Illinois. September 2006-January 2007.
MMWR 2008;S7(29):796-99.
Kirkland, K.B. et al. Outbreaks of respiratory illness mistakenly attributed to
pertussis- New Hampshire, Massachusetts, and Tennessee, 2004-2006. MMWR
2007;56(33):837-842.
130
Wooten, K.G. et al. National, state and local area vaccination coverage among
children aged 19-35 months-United States, 2006. MMWR 2007;56(34):880-85.
Number of cases
Figure 74. Pertussis Cases in Illinois, 2001-2006
2000
1554
1500
922
1000
500
588
321
231
194
0
2001
2002
2003
2004
2005
2006
Year
Incidence of c ases
Figure 75. Age Distribution of Pertussis Cases in Illinois, 2006
40
30
20
10
0
<1 yr
1-4 yr
5-9 yr
1 0-19 yr
>19 years
Yea r
Number of cases
Figure 76. Pertussis Cases in Illinois by Month, 2006
100
80
60
40
20
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
131
Aug
Sep
Oct
Nov
Dec
Q Fever
Background
Q fever is an acute rickettsial disease. Coxiella burnetti is the causative agent. Q
fever is a worldwide zoonosis. Phase I is found in nature and phase II after multiple
laboratory passages in the laboratory. The infective dose can be very low, as low as
one organism. The diagnosis of Q fever relies on serologic testing. In 60 percent of
cases, acute Q fever can be asymptomatic. In patients with symptoms, it is usually mild
and sometimes complicated by febrile illness, pneumonia or hepatitis infection.
Chronic Q fever may appear as endocarditis. Persons at higher risk of infection include
animal workers. The animal reservoirs include sheep, cattle, goats, cats, dogs, and
some wild animals. The organism can be shed in high quantities in placental fluids at
parturition. Ticks can be a rare source of infection in the United States. Q fever is most
commonly transmitted through airborne dissemination of the organism in dust from
premises contaminated with placental tissues and excreta of infected animals, in
necropsy rooms or in animal processing establishments. Rarely, it can be transmitted
from consumption of unpasteurized milk or cheese. The incubation period is from two to
three weeks. Q fever is also a Category B bioterrorism agent. Outbreaks have been
linked to aerosol transmission in heavy winds.
In 2006, 169 cases of Q fever were reported to CDC.
Case definition
A confirmed case of Q fever is a clinically compatible illness with either isolation of C.
burnetti from a clinical specimen, demonstration of C. burnetti in a clinical specimen by
detection of antigen or nucleic acid, or a fourfold or greater change in serum antibody
titer to C. burnetti antigen. A probable case is defined as a clinically compatible or
epidemiologically linked case with an elevated serum antibody titer to C. burnetti.
Descriptive epidemiology
•
Number of cases reported in Illinois in 2006 – 17 cases were reported. One was
confirmed.
•
•
•
Age - Cases ranged in age from 14 to 74 (mean = 45 years-of-age)
Gender - Females comprised 41 percent of cases.
Race/ethnicity – Sixty-nine percent were white, 8 percent were African American,
and 23 percent were other races. Four cases had unknown race; 15 percent
reported Hispanic ethnicity.
Seasonal variation - Cases reported onsets from January through December.
(Figure 78).
Hospitalization – Seven of 12 cases (58 percent) were hospitalized. No fatalities
were reported.
Reporting - Forty-one percent of cases were reported by laboratories.
Geographic location – Twelve counties reported cases. Counties reporting
multiple cases included Stephenson (three), Rock Island (two), Pike (two) and
•
•
•
•
132
•
Kane (two).
Risk factors – Five cases reported exposure to cattle, sheep or goats. No cases
reported consuming unpasteurized dairy products.
Summary
Seventeen cases of Q fever were reported in 12 Illinois Counties. Only five
reported a history consistent with exposure to cattle, sheep or goats.
133
Rabies
Background
In the United States, rabies is a disease that affects primarily wildlife populations.
It is a neurologic illness that follows infection with a rhabdovirus. It produces
encephalitis and typically progresses to death. Transmission of rabies to humans results
from the bite of a rabid animal or from contact between the saliva of a rabid animal and
a mucous membrane or wound. The rabies virus is inactivated by sunlight, heat and
desiccation.
The incubation period is usually three to eight weeks. Symptoms may include
fever, anxiety, malaise, and tingling and pruritus at the bite site. Neurologic signs,
beginning two to 10 days later, may include hyperactivity, paralysis, agitation, confusion,
hypersalivation and convulsions. The paralytic form of rabies must be differentiated from
Guillain Barré syndrome. After two to 12 days, the patient may go into a coma and
experience respiratory failure. Rabies should be considered in the differential diagnosis
of any acute rapidly progressive encephalitis, regardless of documentation of an animal
bite.
In 2006, the United States and Puerto Rico reported three cases of human rabies
and 6,940 cases of animal rabies. Wild animals accounted for 92 percent of the animal
cases reported in the United States; the top three species with rabies were the raccoon,
bat and skunk. The top six rabies-positive bats after speciation (not done in all states)
were the big brown bat (64 percent), Mexican free-tailed bat (9 percent), little brown bat
(8 percent), Western pipistrelle (4 percent), red bat (4 percent) and hoary bat (3
percent). The most commonly identified rabid bat in the United States was the big
brown bat. The peak of bat rabies in the United States occurs in August. Rabies virus
transmission among bats is mainly intraspecific. In a study of bats submitted for rabies
testing in Minnesota in 2003, rabid bats were more likely than non-rabid bats to be
found in September, found outside, found in a wooded area, unable to fly, acting ill, or
acting aggressively. Rabid bats were not more likely to be found during the day or to
have bitten someone.
Three human cases of rabies occurred in the United States in 2006. The cases
were residents of Texas, Indiana and California. The Texas and Indiana cases were
linked to bat exposures. The California case was in a patient who had been bitten by a
dog while living in the Philippines.
From 1990 to 2006, 51 human rabies cases were reported in the United States
and Puerto Rico. Thirty-seven of 40 (92 percent) were infected with rabies variants
associated with bats.
Over the past 40 years in Illinois, the skunk and bat have been the main wildlife
reservoirs of rabies virus. The last human case of rabies in Illinois was reported in 1954.
Case definition
The case definition for human rabies is a clinically compatible illness that is
laboratory confirmed. Laboratory confirmation is through detection by direct fluorescent
antibody of viral antigens in a clinical specimen (preferably brain tissue or punch biopsy
of the nape of neck, including at least 10 hair follicles where associated nerves are likely
133
to show evidence of infection), or isolation of rabies virus from saliva or cerebrospinal
fluid (CSF), or identification of a rabies-neutralizing titer of greater than 1:5 in the serum
or CSF of an unvaccinated person. A case of animal rabies is confirmed by DFA of
brain tissue. If samples are sent to CDC, as is normally done only for confirmation of a
positive result in a domestic species, the CDC results are used as the final results for
the purposes of this report.
Descriptive epidemiology
Number of animals submitted for rabies testing in Illinois in 2006 – 4,515; 59 additional
heads did not meet criteria established by the testing laboratories (Illinois Departments
of Agriculture and Public Health). Examples of unsatisfactory specimens are those
determined to be too decomposed or too damaged to test. Forty-six specimens were
DFA positive; all were bats (Table 5). Trends in animal rabies testing in Illinois are
shown in Figure 77.
•
•
•
Rabies positivity rate - Table 6 shows the rabies positivity rate in different species
of animals in Illinois from 1971 to 2006. This information can be useful in
explaining why rabies PEP is not recommended for the large majority of mouse,
rat and squirrel bites. No rats, mice or squirrels have been identified with rabies
in Illinois in more than 30 years. Because bats with rabies are identified almost
every year in Illinois, rabies PEP is recommended for exposures to these animals
and many other wild mammals unless they can be tested and are negative for
rabies. When comparing the positivity rates for cumulative 1971-2006 data vs.
1991-2006 data, the percentage of skunks positive for rabies declined
dramatically, and the percentage of positive bats stayed very constant.
Exposures to rabid bats - There were 46 rabid bat situations.
o In 35 of the 46 rabid bat situations, no human exposures sufficient to
require rabies PEP (per ACIP guidelines) occurred (for three situations,
the human exposure information was unknown at the time of this report).
In 16 situations, bats were found inside homes. In 19 situations the bat
was found alive outside in yards, pools or near barns, and in 11 situations
the location of where the bat was found was unknown.
o Domestic animals (all dogs or cats) were either exposed or possibly
exposed in 17 situations (Table 7).
Testing of bats - Bats accounted for all of the confirmed rabid animals in 2006.
The total number of bats tested for rabies was 1,311 (positivity rate = 3.5
percent).
o Geographic distribution - Rabid bats were dispersed in 20 counties across
the state (Figure 78). The following counties had rabid bats: Bureau (one),
Champaign (four), Cook (five), DeKalb (one), DuPage (two), Edwards
(one), Fulton (one), Jackson (one), Kane (one), Lake (three), McHenry
(two), McLean (two), Massac (one), Ogle (one), Piatt (one), Sangamon
(five), Vermilion (three), Will (four), Williamson (two) and Winnebago (five).
 Speciation - The Illinois Natural History Survey speciates bats
tested for rabies in Illinois. In 2006, 1,246 bats tested for rabies
134
were speciated. Forty-six positive bats were speciated including the
big brown bat (32), eastern red bat (six), hoary bat (three), eastern
pipistrelle (three), silver-haired bat (one) and little brown bat (one).
Of the 1,200 negative bats speciated, the following results were
found: big brown bat (891), silver-haired bat (144), little brown bat
(28), northern long-eared bat (19), hoary bat (eight), eastern
pipistrelle (seven), evening bat (five), Indiana bat (one), Mexican
free-tailed bat (one) and Myotis sp, not further identified (five).
o Seasonal variation - Figure 79 shows bats submitted for testing by month
in 2006. Bats submitted for rabies testing increase in August and
September.
•
Testing of skunks - Rabies testing was performed on 125 skunks in 2006 as
compared to 216 in 2005. At least one skunk from each of 27 Illinois counties
was tested; no skunks were tested in 75 counties. The following counties
submitted more than five skunks for rabies testing: DuPage (28 skunks tested),
Cook (16), Lake (14), McHenry (12), McLean (12) and Will (12).
For rabies surveillance to be optimal in Illinois an adequate number of skunks,
the main terrestrial animal reservoir, must be tested. Test results from wild
terrestrial mammals is one factor used to determine whether rabies PEP is
recommended in cases of stray dog and cat bites. If enough skunks from
throughout the state are not tested, recommendations against rabies PEP
following such a bite cannot be made with confidence.
Figure 80 shows the number of rabid skunks found in Illinois and the road kill
index from 1975 through 2006. The road kill index is calculated by the Illinois
Department of Natural Resources as a measure of changes in the skunk
population size. When the road kill index increases, the skunk population is
increasing, and conditions are likely to be suitable for a rabies epizootic in
skunks. This last occurred in the late 1970s and early 1980s, when the road kill
index and the rate of skunks testing positive for rabies both increased.
Summary
Bats were the main species identified with rabies in Illinois in 2006. Illinois was
one of six states reporting rabies in bats but not in terrestrial animals. Testing of skunks
for rabies has declined in Illinois, thereby decreasing the reliability of surveillance of the
terrestrial animal reservoir in the state. Local animal control jurisdictions are encouraged
to increase submission of skunks for rabies testing to maintain surveillance in this
species.
Suggested readings
Liesener, A.L., et al. Circumstances of bat encounters and knowledge of rabies
among Minnesota residents submitting bats for rabies testing. Vector-borne and
Zoonotic Disease 2006; 6(2): 208-215.
135
Table 5. Animal rabies testing in Illinois in 2006
Species
Total number suitable
for testing
Total
positive
Bat
1,311
46
3.5
Cat
952
0
0
Cattle/buffalo
111
0
0
1,573
0
0
Coyote/fox/wolf
21
0
0
Ferret
6
0
0
Horse/donkey
Opossum
29
0
0
31
0
0
Raccoon
156
0
0
Rodents/lagomorphs
167
0
0
Sheep/goats
11
0
0
Skunk
125
0
0
Other*
22
0
0
Dog
% positive
TOTAL
4,574
46
N/A
*”Other” species tested in 2006 included alpaca, deer, kangaroo, lion and llama.
Source: Illinois Department of Public Health
136
1500
1000
# skunks tested
# bats tested
500
20
06
20
04
20
02
20
00
19
98
19
96
19
94
19
92
0
19
90
Number of
animals tested
Figure 77. Trends in Animal Rabies Testing in Illinois,
1990-2006
Year
Table 6. Rabies Positivity Rate by Animal Species in Illinois, Selected Time Spans
1971-2006
Species
1991-2006
# tested
# positive
% positive
# tested
# positive
% positive
Bat
14,895
692
4.6
9,722
390
4.9
Cat
45,584
141
0.3
18,586
4
0.02
Cattle
3,919
215
5.5
1,487
4
0.27
Dog
47,964
110
0.2
24,419
5
0.02
Fox
1,452
73
5.0
267
1
0.37
Horse
762
23
3.0
305
1
0.3
Mouse
4,749
0
0
704
0
0
Raccoon
9,903
17
0.2
3,621
0
0
Rat
1,885
0
0
375
0
0
Skunk
7,829
2,532
32
1,661
50
3.0
Squirrel
7,128
0
0
1,966
0
0
Source: Illinois Department of Public Health
137
Table 7. Type of Exposure to Rabid Bats by Month, Illinois, 2006
County
Date
Human exposure?
Animal
exposure?
January
DeKalb
None; picked up with pliers
11 dogs and cats
April
Ogle
None
May
DuPage
May
May
May
McHenry
Winnebago
Winnebago
May
June
June
June
July
July
July
Sangamon
Will
Williamson
Will
Edwards
Fulton
Vermilion
July
Piatt
July
July
August
Cook (Chicago)
Vermilion
Williamson
None, one bat in home; 2 family
members decided to get treatment
anyway
None, five family members
decided to get PEP anyway
None
None
One person woke up to bat in
room; three household members
received rabies PEP
None, but child received treatment
Unknown
None
One person bitten
None
None
None, but four persons received
rabies PEP
One person bitten and received
rabies PEP
None
None
None
August
Sangamon
August
Champaign
August
Lake
August
August
Cook
Massac
None; One received PEP after
picking up bat with towel
None; Bat in home; three
household members received
rabies PEP
Three persons received PEP;bat
swooping at head
None
None
August
August
McHenry
Lake
None, two persons received PEP
One person
138
One vaccinated
dog
None
Cat
None
None
Unknown
Cat
Unknown
None
Unknown
Unvaccinated
dog
Unknown
None
None
Unvaccinated
puppy had to be
euthanized
Unvaccinated
puppy
None
None
None
Two vaccinated
dogs
None
Unknown
August
Cook (Chicago)
Six persons received PEP
August
August
August
August
Winnebago
Will
Lake
Champaign
August
August
August
August
Winnebago
Will
Sangamon
Sangamon
August
McLean
August
August
August
September
DuPage
Jackson
Cook
Kane
Unknown
None
None
One person exposed, two others
also received PEP
Unknown
None
One person received PEP
None, but three persons received
PEP
One child left alone with bat; three
persons received PEP
None
None
None
One animal control officer had
bare handed contact; three
household members received PEP
with bat in home
September Winnebago
September Bureau
Two received PEP
None
September
September
September
October
October
October
None
None
None
None
None
None
Vermilion
Champaign
Champaign
Sangamon
Cook (Chicago)
McLean
Source: Illinois Department of Public Health
139
Two
unvaccinated
cats
Vaccinated cat
Vaccinated dog
None
Two vaccinated
dogs
Unknown
None
Cat
Dog
None
None
None
None
Two
unvaccinated
cats euthanized
and one
vaccinated dog
None
Two
unvaccinated
cats confined
None
None
None
None
None
Vaccinated dog
Figure 78. Geographic Distribution of Rabid Animals in Illinois, 2006
Jo Daviess
0
Stephenson Winnebago Boone McHenry
0
5
2
0
Carroll
0
Ogle
1
DeKalb
1
Whiteside
0
Kane
1
Lake
3
DuPage Cook
2
5
Lee
0
Kendall
0
Rock Island
0
Mercer
0
McDonough
0
Tazewell
0
Mason
0
Brown
0
Pike
0
Scott
0
Morgan
0
Livingston
0
Iroquois
0
De Witt
0
Calhoun
0
Jersey
0
Macon
0
Sangamon
5
Douglas
0
Moultrie
0
Shelby
0
Macoupin
0
Montgomery
0
Madison
0
Bond
0
Marion
0
Randolph
0
Franklin
0
Williamson
2
Union
0
Hamilton
0
Pulaski
0
140
Massac
1
Lawrence
0
Wabash
0
Edwards
1
White
0
Saline Gallatin
0
0
Johnson
Pope
0
0
Crawford
0
Richland
0
Wayne
0
Jackson
1
Alexander
0
Jasper
0
Clay
0
Jefferson
0
Perry
0
Clark
0
Cumberland
0
St. Clair
0
Washington
0
Edgar
0
Coles
0
Effingham
0
Fayette
0
Clinton
0
Monroe
0
Vermilion
3
Champaign
4
Piatt
1
Christian
0
Greene
0
Ford
0
McLean
2
Logan
0
Menard
0
Cass
0
Grundy
0
Kankakee
0
Woodford
0
Peoria
0
Fulton
1
Will
4
Marshall
0
Knox
0
Schuyler
0
Adams
0
La Salle
0
Putnam
0
Stark
0
Henderson Warren
0
0
Hancock
0
Bureau
1
Henry
0
Hardin
0
Table 8. Bat speciation results from bats submitted for rabies testing in 2006
Species
Common Name # testing neg.
Eptesicus
Big brown bat
913
fuscus
Lasiurus
Red bat
93
borealis
Lasiurus
Hoary bat
8
cinereus
Lasionycteris
Silver-haired bat 152
noctivagans
Pipistrellus
Eastern
7
subflavus
pipistrelle
Myotis
Little brown bat
28
lucifugus
Myotis
Northern long20
septentrionalis eared bat
Nycticeius
Evening bat
5
humeralis
Myotis sodalist Indiana bat
1
Myotis spp
5
Tadarida
Mexican free1
brasiliensis
tailed bat
Unknown
2
TOTAL
1,235
Source: Illinois Natural History Survey
# testing pos.
32
# unsatisfactory
21
6
6
3
0
1
0
3
0
1
0
0
1
0
0
0
0
0
0
0
0
0
46
3
31
Number of bats
tested
Figure 79. Bat Testing for Rabies by Month, 2006
500
400
300
200
100
0
Jan
Feb
Mar
Apr
May
June
Jul
Month of testing
141
Aug
Sep
Oct
Nov
Dec
Year
Rabid skunk
Road kill index
142
2005
2003
2001
1999
1997
1995
1993
1991
1989
1987
Road kill index
0
1985
0
1983
2
1981
200
1979
6
4
1977
600
400
1975
Number of
rabid skunks
Figure 80. Skunk Rabies and Skunk Road Kill Index
in Illinois, 1975-2006
Rabies, Potential Human Exposure
Background
Exposures to animals, especially those involving bites or bat exposures, often result
in the need for public health consultation on whether rabies post-exposure prophylaxis
(PEP) is needed for the exposed individual. All animal bites in Illinois are reportable to
local animal control for the purposes of following up with the owner of the biting animal.
Animal control authorities are responsible for ensuring that dangerous animals are
maintained so that they cannot injure the public. Potential human rabies exposures are
reportable to human health including all instances when rabies post-exposure prophylaxis
is initiated and all exposures to bats.
In France a study of rabies PEP was conducted using data from 1999 to 2001.
The incidence of rabies PEP was 16 per 100,000. Dogs accounted for 81 percent of
situations resulting in PEP. The time between the injury and consultation was 2.6 days.
Animals were available for observations for one-third of cases.
Case definition
The definition of exposed person to be reported is:
1)
Any contact (bite or non-bite) with a bat, or
2)
Any contact (bite or non-bite) with an animal that subsequently tests
positive for rabies virus infection, or
3)
Anyone who was started on rabies post-exposure prophylaxis, or
4)
Exposure to saliva from a bite, or contact of any abrasion or mucus
membrane with brain tissue or cerebrospinal fluid of any suspect rabid
animal. Exposure to healthy rabbits, small rodents, indoor-only pets or
rabies-vaccinated dogs, cats or ferrets is excluded, unless the exposure
complies with subsections (a)(1) through (a)(3) above, or the animal
displays signs consistent with rabies.
Descriptive epidemiology
The following information was obtained from Illinois National Electronic Disease
Surveillance System and investigation forms obtained during the surveillance of rabies,
potential human exposures (RPHE) in Illinois during 2006. The investigation forms had
questions on demographics, exposure characteristics and rabies post-exposure
treatment information. Not all local health jurisdictions have submitted investigation
143
forms so this is a minimum estimate of the number of potential human rabies exposures
in Illinois.
•
•
•
•
•
Number of cases reported in Illinois in 2006 - There were 314 potential human
rabies exposures reported. Note: Seven persons receiving rabies PEP after
exposure to rabid bats were inadvertently excluded from the 314 exposed
persons. The following information is based on the 314 potential human rabies
exposures.
Age – Ages ranged from younger than 1 year of age to 94 years of age. The
mean age of those exposed was 34 years.
Gender – Fifty-one percent of RPHE reports were in males.
Seasonal peak – Higher numbers of exposures occurred in the summer months
of May through August.
Geographic location – Forty-one counties reported at least one RPHE. Fiftyseven percent of exposures took place in urban settings.
Type of exposure
Three types of exposures can be summarized from the reports: bite, non-bite
(scratch or abrasion or contamination of open cuts with saliva or nervous tissue, bat
present in room with sleeping person or physical contact with a bat where a bite cannot
be ruled out) or non-exposure (petting, handling, blood contact, bat in room but no
physical contact and no one asleep). Of the 314 total exposures reported, 115 (37
percent) were due to animal bites, 136 (44 percent) from non-bite exposures and 61 (20
percent) no human exposure meeting ACIP guidelines for rabies PEP.
Of the 98 bite exposures with the site of bite reported, most bites were to the arm
or hand, 73 (74 percent), followed by leg or foot, 19 (19 percent), head or neck, three (3
percent) and torso, three (3 percent). The bite site was not indicated for 17 bite
exposures.
Of the 131 non-bite exposures due to bats, bats were found in the room with a
sleeping person in 92 (71 percent) of exposures, physical contact with a bat took place
in 27 (21 percent) of exposures, a child or adult with dementia was unobserved with a
bat in four (3 percent) and bat was in a house in seven (6 percent). Bats were tested in
32 of the non-bite bat situations. Nineteen bats tested negative, seven tested positive
and six specimens were unsuitable for testing. The other non-bite exposures included
exposure to saliva from a possibly rabid wild animal (three), rabid horse saliva (one) and
sharps injury while cutting into brain tissue (one).
Animals causing exposure
The following information is by each individual person’s exposure history.
Multiple individuals may have been exposed to a single animal. Of 314 animals causing
exposures, 258 (83 percent) were wild, not domesticated animals. The types of animals
causing exposures included bat, 223 (71 percent); cat, 27 (9 percent); dog, 25 (8
percent); raccoon, 23 (7 percent) and other, 13 (4 percent). The type of animal was
unknown for three exposure situations. Of the 52 domestic animals exposing persons,
33 (73 percent) were described as stray and 12 (27 percent) were owned. Of the dogs
144
that exposed an individual, 13 (62 percent) of these animals had an unknown
vaccination history, five (24 percent) were not rabies vaccinated and three (14 percent)
were previously vaccinated but not up-to-date on rabies vaccinations. None of eight
owned dogs causing exposures were known to be up-to-date on their rabies
vaccinations. Rabies vaccination of dogs is required in Illinois. Of the 27 cats that
exposed an individual, 16 (76 percent) of these animals had an unknown vaccination
history and four (19 percent) were not rabies vaccinated. One cat was up-to-date on
rabies vaccination. Thirty-one (79 percent) of bites from dogs and cats were provoked.
For domestic animal exposures, 40 (82 percent) were unavailable for either
confinement or testing, four (8 percent) were tested for rabies and five (10 percent)
were confined for observation. Four (9 percent) of the owned domestic animals were
owned by the family of the person bitten and eight (18 percent) were owned by another
individual.
There were 186 (73 percent) of wild animals that were not available for
confinement or testing. Sixty-nine (27 percent) of animals potentially exposing someone
to rabies were submitted for rabies testing. Of the 69 wild animals submitted for rabies
testing, 31 (45 percent) were negative, 28 (41 percent) were rabies positive and 10 (14
percent) were unsuitable for testing. Twenty-eight people were exposed to rabid bats.
Note: An additional 21 person received rabies PEP after rabid bat exposures but were
not entered into this database. The specimens that were unsuitable for testing were
from nine bats and one skunk.
In 10 exposures, the exposing animal was reported to exhibit signs of rabies.
Signs of rabies included aggression, five (50 percent); no fear of humans, one (10
percent); other, two (20 percent) and multiple, two (20 percent).
Rabies post-exposure prophylaxis (PEP)
During 2006, 262 persons were reported to have started rabies PEP. The first
recommendation about whether rabies PEP was needed for a person starting rabies
PEP came from the following sources: public health personnel, 92 (37 percent), health
care provider, 149 (61 percent) and other, five (2 percent).
The final recommendation on rabies PEP for those starting rabies PEP came
from public health personnel, 98 (40 percent) and health care provider, 142 (58
percent). For 16 exposed persons receiving PEP, the source of the final
recommendation was not known.
For 137 (69 percent) of persons with information available, rabies PEP was
completed in an emergency department followed by completion in a physician’s office,
52 (26 percent). Most rabies PEP was paid for by private insurance, 115 (77 percent),
followed by Medicare or Medicaid, 16 (11 percent), no payment source, eight (5
percent), worker’s compensation, two (1 percent) and out-of-pocket expense, eight (5
percent). Payment source was unknown for 113 persons. Seventeen (6 percent) of
persons recommended for rabies PEP refused to be treated. None developed rabies.
Rabies PEP was completed in 217 (83 percent) of 261 persons for whom
information was available. In 25 persons, rabies PEP was not completed. In 10 persons
rabies PEP was not completed because the animal was tested negative. Of these 10
situations, six were bat exposures, three were raccoon exposures, and one was a dog
145
exposure. The rabies PEP recommendation for these 10 persons was made mainly by
health care providers (seven situations). In five (21 percent) of situations, the animal
was a low-risk species, in seven (29 percent) of situations the patient refused to
complete treatment, in one situation the person was lost to follow-up, one person had
other reasons and the reason was unknown for one person.
Decisions on rabies PEP should be based on the Advisory Committee on
Immunization Practices (ACIP) guidelines. For 298 exposed persons, it was possible to
determine if the PEP recommendation followed ACIP guidelines. For 181 (61 percent)
of these persons, rabies PEP was recommended and the recommendation followed
ACIP guidelines. For 95 (32 percent) of persons, rabies PEP was recommended but this
was not correct according to ACIP guidelines. For 22 persons (7 percent), rabies PEP
was not recommended and that was correct according to ACIP. There were no persons
for whom PEP was not recommended and that was an incorrect recommendation. In 95
situations, PEP was recommended incorrectly. In 46 situations, PEP was recommended
when a bat was found in a house, even though no one was sleeping in the room. The
ACIP recommends rabies PEP if the bat is found in a room with a sleeping person or
person who is unable to say whether they were bitten. In 12 situations an animal that
exposed someone tested negative for rabies but PEP was started. Because the
turnaround time is rapid for rabies testing, PEP can be delayed until the testing of the
animal takes place. Because of the lack of terrestrial animal rabies in the last few years
in Illinois, no rabies PEP would be recommended if the dog or cat bite was provoked
and the animal showed no signs of rabies. In 26 situations, persons were recommended
for PEP even though a domestic animal exposed the person with a provoked bite and
was not acting abnormally. In four situations a low risk animal, rodent or opossum, bit
someone and PEP was recommended. In seven situations persons who were not
exposed to saliva or neurologic tissue were incorrectly recommended for rabies PEP.
Of the persons exposed, 217 completed rabies PEP. For 45 of 161 (28 percent)
persons completing rabies PEP and with information available, the ACIP rabies protocol
was followed exactly. One hundred nineteen people had incorrect administration of
rabies PEP. Types of incorrect administration were incorrect timing of injections (77, 66
percent), multiple problems (16, 14 percent), no RIG given (eight, 7 percent), incorrect
site of administration of injections (16, 14 percent) and two unknown.
Twelve persons started on rabies PEP had been pre-exposure immunized for
rabies.
Summary
There is vast underreporting of potential human rabies exposures in Illinois with
some jurisdictions not reporting any exposures. Therefore, the summary information is
not a complete picture of human rabies exposures in Illinois. Thirty-seven percent of
reported exposures were due to bites. Most bites were to the hand or arm which is
typical as persons reach to pick up or handle an unfamiliar animal. Of the non-bite
exposures, 71 percent of reported exposures were from bats found in a room with a
sleeping person. Education of the public and animal control personnel could result in
increased submission of bats that have exposed person in homes being tested for
rabies. If the bat tests negative, the person would not need rabies PEP.
146
The main animal causing potential human rabies exposures was the bat,
followed by the cat, dog and raccoon. This is primarily due to the definition of possible
rabies exposure to a bat. The bat is the only wild mammal where rabies PEP is
recommended if a person is in a room sleeping where a bat is found and it cannot be
tested, or tests positive.
Fifty-eight percent of final rabies PEP recommendations were made by
emergency department health care providers or other health care providers. This
indicates the importance of providing health care providers with up-to-date information
on rabies incidence in their area and on rabies PEP recommendations.
Thirty-two percent of rabies PEP given in 2006 would not have been
indicated according to public health guidelines. In some situations persons were started
on rabies PEP even though the animal was available for testing. Health care providers,
especially in emergency departments, should be advised that rabies testing of animals
can be completed rapidly at the state laboratories, and, if necessary, emergency testing
can be requested for high priority specimens on holidays or weekends. For emergency
testing, health care providers can contact local health department personnel or use the
state emergency phone number. Rabies PEP can be delayed until testing is completed
if testing is prompt.
The rabies PEP protocol is provided in, “Human Rabies Prevention-United
States, 1999. Recommendations of the Advisory Committee on Immunization Practices
(ACIP): MMWR 1999;48(RR-1)”. In 28 percent of cases where rabies PEP was
completed, PEP was administered correctly. Common errors in administration included
incorrect timing of injections and forgetting to administer RIG. The ACIP
recommendation for rabies PEP should be adhered to when administering rabies PEP.
It can be difficult to get exposed individuals to adhere to a complicated vaccination
schedule but the person should be informed about the universally fatal nature of rabies
and the importance of adhering to the ACIP schedule.
Suggested readings
Gautret, P. et. al. Rabies post exposure prophylaxis, Marseille, France, 19942005. EID (serial on the Internet) 2008. Sep. Avail from
http://www.cdc.gov/EID/content/14/9/1452.htm.
147
Rocky Mountain Spotted Fever
Background
Rocky Mountain spotted fever (RMSF) is the most frequently reported fatal tickborne disease in the United States. RMSF has been reported throughout the continental
United States. The causative agent is Rickettsia rickettsii. Both dogs and humans may
experience clinical illness due to RMSF.
In 2006, 2,288 human cases were reported nationally to the CDC. Most cases
are reported from April through September when the greatest number of Dermacentor
ticks are present in the environment.
The ticks that are most likely to transmit RMSF include the American dog tick
(Dermacentor variabilis) in the central United States. Only about 1 percent to 5 percent
of ticks usually are infected with R. rickettsii in an area where transmission to humans
occurs. In order for one of these ticks to transmit the bacteria, it must be attached for at
least four to six hours. A history of a tick bite can be elicited in approximately 60 percent
of RMSF cases.
The incubation period for RMSF is three to 14 days after a tick bite. Common
presenting symptoms include high fever, severe headache, deep myalgias, fatigue,
chills and rashes. A rash typically appears within two to four days after onset of fever.
The rash typically begins on the ankles, wrists or forearms. A rash can be atypical or
absent in up to 20 percent of RMSF cases. Starting most often on the ankles and
wrists, the rash then appears on the trunk, palms and soles. Patients also may have
gastrointestinal signs such as abdominal pain and nausea which may be serious
enough to lead to an erroneous diagnosis such as appendicitis. RMSF can have a case
fatality rate of 20 percent in untreated persons, while the case fatality rate is 5 percent in
treated persons.
Case definition
The case definition for a confirmed case of RMSF in Illinois is a clinically
compatible illness that is laboratory-confirmed. The laboratory confirmation is a four-fold
or greater rise in antibody titer by immunofluorescent antibody (IFA), complement
fixation (CF), latex agglutination (LA), microagglutination (MA) or indirect
hemagglutination antibody (IHA) test in acute and convalescent specimens ideally taken
more than three weeks apart; or demonstration of positive immunofluorescence of a
skin lesion or organ tissue, positive polymerase chain reaction or isolation of R. rickettsii
from a clinical specimen. A clinically compatible illness is one characterized by acute
onset and fever, usually followed by myalgia, headache and petechial rash. A probable
case is defined as a clinically compatible case with a single IFA serologic titer of at least
64 or a single CF titer of at least 16 or other supportive serology (four-fold rise in titer or
a single titer at least 320 by Proteus OX-19 or OX-2, or a single titer at least 128 by an
LA, IHA or MA test).
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – Twenty-six cases were reported and
all were probable cases (five-year median = 12).
148
•
•
•
•
•
•
•
•
•
Age - Cases ranged in age from six to 72 years of age (mean = 39 years).
Gender – Fifteen cases were male (58 percent).
Race/ethnicity - Seventeen cases were white, one reported other race; and nine
cases had unknown race; one case was Hispanic.
Geographic distribution – The majority of the cases resided in the southern Illinois
region (Figure 81).
Seasonal variation - Onsets of the cases ranged from January to November. An
increase in cases occurred from May to August (19 cases).
Symptoms/outcomes – Symptoms reported by cases included fever in 23 cases (92
percent), rash in 11 cases (50 percent), headache in 19 cases (83 percent),
thrombocytopenia in two cases (22 percent) and neurologic in three cases (17
percent). Eleven of 24 cases (46 percent) were hospitalized. No cases were fatal.
Reporting – The majority of cases were reported by laboratories (81 percent).
Tick exposure – Fourteen of 18 (78 percent) of cases with a tick habitat history
reported being in a tick habitat. Of the 12 persons who reported the type of tick
habitat, the following location types were reported: own property (four), farm (three),
park or nature preserve (three) and camp (two). Nine of 18 cases (50 percent)
reported a history of a tick bite. Tick exposures took place primarily in the southern
region of Illinois (13 of 19 cases, or 68 percent). One case reported a Winnebago
County exposure. Five cases reported out of state exposures, one each in
Alabama, Missouri, Hawaii, North Carolina and Wisconsin. Seven had unknown
exposure histories.
Past incidence - Rocky Mountain spotted fever cases reported per year in the state
were: 1991 (five), 1992 (two), 1993 (four), 1994 (11), 1995 (10), 1996 (four), 1997
(three), 1998 (one), 1999 (seven), 2000 (five), 2001 (12), 2002 (12), 2003 (five),
2004 (14) and 2005 (11).
Summary
Most cases of RMSF occurred in summer months and 68 percent reported
exposures in southern Illinois. The number of cases was more than 20 over the fiveyear median but all cases were probable cases with single titers.
149
Figure 81. Exposure Locations for RMSF Cases With In-state Exposures, 2006
Jo Daviess
0
Stephenson Winnebago Boone McHenry
0
1
0
0
Carroll
0
Ogle
0
DeKalb
0
Whiteside
0
Kane
0
Lake
0
DuPage Cook
0
0
Lee
0
Kendall
0
Rock Island
0
Henry
0
Mercer
0
McDonough
0
Tazewell
0
Mason
0
Brown
0
Pike
0
Scott
0
Morgan
0
Livingston
0
Iroquois
0
De Witt
0
Calhoun
0
Jersey
0
Piatt
0
Sangamon
0
Douglas
0
Moultrie
0
Shelby
0
Macoupin
0
Montgomery
0
Madison
0
Marion
2
Randolph
0
Perry
0
Jackson
2
Union
1
Alexander
0
Jasper
0
Clay
0
Williamson
1
Hamilton
0
Pulaski
0
Massac
0
150
Lawrence
0
Wabash
0
Edwards
0
White
0
Saline Gallatin
1
0
Johnson
Pope
1
0
Crawford
0
Richland
1
Wayne
0
Jefferson
0
Franklin
2
Clark
0
Cumberland
0
St. Clair
0
Washington
0
Edgar
0
Coles
0
Effingham
0
Fayette
0
Bond
0
Clinton
0
Monroe
0
Vermilion
0
Champaign
0
Macon
0
Christian
0
Greene
0
Ford
0
McLean
0
Logan
0
Menard
0
Cass
0
Kankakee
0
Woodford
0
Peoria
0
Fulton
0
Will
0
Grundy
0
Marshall
0
Knox
0
Schuyler
0
Adams
0
La Salle
0
Putnam
0
Stark
0
Henderson Warren
0
0
Hancock
0
Bureau
0
Hardin
1
Salmonellosis (Non-typhoidal)
Background
There are more than 2,400 serovars of Salmonella. However, approximately 50
percent of human cases are caused by three serovars: Salmonella enterica ser
Enteritidis, S. ser Typhimurium and S. ser Newport. Transmission to humans is usually
after consumption of contaminated food products. Raw or undercooked meat, eggs, raw
milk and poultry have been identified as vehicles for Salmonella infection. Fresh
produce, such as lettuce, unpasteurized apple or orange juice or sprouts also have
caused outbreaks. A Salmonella ser. Oranienberg outbreak associated with fruit salad
was identified in the northeastern United States in persons associated with long-term
care or hospital settings in 2006. During 2006, three outbreaks of Salmonella were
linked to contact with baby poultry (chicks, ducklings, goslings and baby turkeys)
purchased at agricultural feed stores. The three outbreaks were each traced to a single
hatchery. In a study in Oregon, 18 percent of baby chicks from 10 of 16 agricultural feed
stores tested positive for Salmonella.
Hospital and commercial laboratories are required to submit isolates of
Salmonella to the Department’s laboratory for serotyping. This is necessary to detect
increases in specific serotypes. Identification of serotypes is useful in determining which
patients are likely linked to a common source of infection. Another way to link
Salmonella isolates to a common source is pulse field gel electrophoresis (PFGE). A
new laboratory technique for subtyping isolates is multiple-locus variable-number
tandem repeats analysis (MLVA) and this may prove to be useful in surveillance and
outbreak investigation. This technique is currently available at CDC.
Of the 10 diseases/syndromes (those caused by Campylobacter,
Cryptosporidium, Cyclospora, shiga toxin producing E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica) under active
surveillance in the federal FoodNet sites, Salmonella comprised 6,655 of 17,252 (39
percent) of the reported infections in preliminary data from 2006. The incidence rate
was 14.8 per 100,000 and ranged from 11 to 20 at the 10 FoodNet sites in 2006. In
preliminary data from 2006, 90 percent of isolates were serotyped. The top six
serotypes were: Typhimurium (19 percent), Enteritidis (19 percent), Newport (9
percent), Heidelberg (4 percent), Javiana (5 percent), Montevideo (4 percent) and
monophasic serotype I 4,[5],12:i:- (4 percent).
In the United States national surveillance data, 45,808 cases of Salmonella were
reported to CDC in 2006. Serotypes Typhimurium and Enteritidis were the most
common. Of the nationally reported cases in six states in 2002, the median time from
onset of illness to interview of patients was 14 days. The median time from onset to
PFGE typing was 18 days.
Case definition
The case definition for a confirmed case is isolation of Salmonella from a clinical
specimen. The case definition for a probable case is a person who has a clinically
compatible illness that is epidemiologically linked to a confirmed case, but is not
laboratory-confirmed.
151
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 1,603 (five-year median = 1,770) (see
Figure 82 for number of cases since 1997). The annual incidence rate for
salmonellosis in Illinois in 2006 was 13 per 100,000 population.
• Age – Salmonellosis occurred in all age groups (mean age=48) (see Figure 83).
However, the incidence rate was highest in those younger than 1 year of age (67
cases per 100,000 population), followed by those in the 1 to 4 year age group (30
per 100,000).
• Gender – Fifty-two percent were female.
• Race/ethnicity – Seventy-six percent of cases were white, 13 percent African
American and 11 percent other races; 21 percent were Hispanic.
• Seasonal variation - A peak in salmonellosis cases occurred in the summer months,
especially July and August (Figure 84).
• Geographic distribution – For 2006, the counties with the highest incidence per
100,000 population were Massac (40), Clark (35), Gallatin (31), Cass (29), Kane
(27) and Henry (27). The mean annual incidence rates for salmonellosis were
highest in some scattered counties in the state (Figure 85).
• Serotypes - Ninety-four percent of Illinois’ Salmonella isolates were serotyped. The
most common serotypes in 2006 are found in Table 9. The four most common
serotypes were S. ser. Enteritidis (309, 21 percent), S. ser.Typhimurium (303, 20
percent), S. ser. Newport (131, 9 percent) and S. ser. Heidelberg (80, 5 percent).
Serotypes of Salmonella found in Illinois from 1998-2006 are shown in Table 10. The
percent of infections acquired from exposures outside the United States varied by
serotype (See Table 11). For 12 serotypes (Agona, Braenderup, Enteritidis,
Heidelberg, Infantis, Montevideo, Muenchen, Newport, Oranienberg, Paratyphi A,
Paratyphi B and Typhimurium), S. ser. Paratyphi A cases reported the highest
percent of acquisition outside of the United States (91 percent).
• Clinical syndrome – Cases reported diarrhea (92 percent), fever (68 percent) and
vomiting (40 percent). Urinary tract infections were reported in 111 cases (60 also
reported diarrhea, 44 did not report diarrhea and seven had no history of whether
diarrhea was present). Of the following 12 serotypes (Agona, Braenderup,
Enteritidis, Heidelberg, Infantis, Mbandaka, Montevideo, Muenchen, Newport,
Oranienberg, Tennessee and Typhimurium), S. ser. Tennessee had the highest
percent of isolates with urinary tract infections (100 percent), followed by
Braenderup (24 percent). Thirty-five percent of Salmonella cases were admitted to
the hospital. Two deaths were attributed to Salmonella.
• Risk factors
Animal contact
• Contact with animals was reported from 542 of 1,228 (44 percent) of cases. A
history of reptile or amphibian contact was reported by 80 Salmonella cases in
2006, but a link between the reptiles and transmission of the infection was not
confirmed by culture of reptiles or amphibians.
 Cases reported contact with the following types of reptiles: turtles (24),
152
lizards (15), snakes (13), not specified (11) and multiple types (nine).
 For those with reported reptile or amphibian contact, the mean age was 25
years; 22 cases were younger than 5 years of age.
 Males accounted for 46 percent of the cases.
 The two most common species in these cases were Enteritidis (19) and
Typhimurium (18). Salmonella isolates from the subspecies I, II, III and IV
have been associated with reptile contact and, for the 2006 reptile contact
cases, the following serotypes from these groups were identified:
Monschaui (one) and Telelkebir (one).
Travel exposure
 Of the 1,117 cases, 126 (11 percent) cases reported being in another
country during their incubation period. The most common exposure
destination was Mexico (50 cases), followed by India (13) and the
Dominican Republic (six). There were 44 of 1,117 (4 percent) of the cases
reporting travel within the United States but outside Illinois during their
incubation period. The most common exposure states were Florida (six
cases), Wisconsin (five cases) and Nevada (four).
Swimming exposure
 Eighty-eight of 1270 cases (7 percent) reported swimming in nonchlorinated water and 127 of 1234 cases (10 percent) reported swimming
in chlorinated water.
Residential or day care exposure
 One hundred eleven of 1,294 cases (8 percent) reported contact with a
residential facility, and 87 of 1,292 cases (7 percent) reported contact with
a day care.
 Twenty-nine cases attended a day care and six lived in a residential
facility.
Sensitive occupations
 Sensitive occupations reported in cases included food service facility
worker (32), health care worker (29), day care center (four), residential
facility (three) and other sensitive occupations (17).
•
Reporters – Cases were reported primarily by infection control professionals
(46 percent), followed by laboratory staff (44 percent) and health clinic staff (four
percent).
•
Outbreaks - There were four confirmed foodborne outbreaks of Salmonella
reported in 2006 (See the section of this report on foodborne outbreaks for more
details). No person-to-person outbreaks were reported due to Salmonella.
Summary
In 2006, 1,603 cases of Salmonella were reported in Illinois. The one-year
incidence rate of Salmonella for 2006 was 13 per 100,000 population, which is lower
than the average incidence reported at CDC’s FoodNet sites (15 per 100,000). The
mean age for Salmonella cases was 48 years, although the incidence was highest in
those younger than one year of age. Salmonella cases increased in Illinois during the
summer which is similar to national data. The percentage of isolates that were
153
serotyped in Illinois was 94 percent, which is higher than the 90 percent of isolates
serotyped in FoodNet sites. The percentages of the four most common serotypes were
Typhimurium (20 percent), Enteritidis (21 percent), Newport (9 percent) and Heidelberg
(5 percent). The proportions of these four serotypes was similar to the 2006 FoodNet
preliminary data for those serotypes. Reptile or amphibian contact was reported in 22
cases younger than 5 years of age. CDC recommends that households with children
younger than 5 years of age not have reptiles as pets.
Suggested readings
Bidol, S., et al. Three outbreaks of Salmonellosis associated with baby poultry
from three hatcheries. United States, 2006. MMWR 2007; 56(12):273-6.
Chatfield, D., et al. Turtle-associated Salmonellosis in humans-United States,
2006-2007. MMWR 2007; 56(26):649-652.
Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states.
Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from
http://www.cdc.gov/EID/content/14/2/311
Landry, L., et al. Salmonella Oranienberg infections associated with fruit salad
served in health-care facilities – Northeastern United States and Canada, 2006. MMWR
2007; 56(39): 1025-8.
Torpdahl, M. et al. Tandem repeat analysis for surveillance of human Salmonella
Typhimurium infections. Emerg Inf Dis, 2007:13(3): [Serial on the Internet]. Available
from http://www.cdc.gov/EID/content/13/3/388.htm.
Number of cases
Figure 82. Salmonella Cases in Illinois, 2001-2006
2500
2000
1500
1000
500
0
1770
1955
1612
1383
2001
2002
2003
2004
1837
1603
2005
2006
Year
Incidence per 100,000
Figure 83. Salmonella Cases in Illinois by Age Group, 2006
80
60
40
20
0
<1 yr
1-4 yr
5-9 yr
10- 19 y r
2 0-29 yr
Age Group
154
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Number of cases
Figure 84. Salmonella Cases in Illinois by Month, 2006
250
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
155
Aug
Sep
Oct
Nov
Dec
Figure 85. Map of One-year Salmonellosis Incidence Rates for Illinois, 2006
Jo Daviess
Stephenson Winnebago McHenry Lake
Boone
Carroll
Ogle
DeKalb
Whiteside
Kane
DuPage Cook
Lee
Kendall
Will
Rock Island
Henry
Bureau
Mercer
La Salle
Stark
Kankakee
Marshall
Knox
Livingston
Henderson Warren
Peoria
Woodford
McLean
Mason
Schuyler
Menard
Cass
Morgan
Vermilion
Champaign
De Witt
Logan
Adams Brown
Iroquois
Ford
Tazewell
McDonough
Fulton
Hancock
Pike
Grundy
Putnam
Piatt
Macon
Douglas
Sangamon
Scott
Christian
Coles
Shelby
Greene
Calhoun
Jersey
Edgar
Moultrie
Cumberland
Macoupin
Montgomery
Fayette
Madison
Effingham
Jasper Crawford
Bond
Clay
Marion
Clinton
St. Clair
Richland Lawrence
Wayne
Washington
Monroe
Randolph
Clark
Perry
Jefferson
Wabash
Edwards
Hamilton White
Franklin
Jackson
Saline Gallatin
Williamson
Union
Pope
Johnson
AlexanderPulaski Massac
156
Hardin
Source: Illinois Department of Public Health
157
Table 9. Top 10 Salmonella Serotypes in Illinois, 2006.
Serotype
Frequency
Serotype
Frequency
Enteritidis
309
Muenchen
30
Typhimurium
303
Infantis
30
Newport
131
Agona
29
Heidelberg
80
Montevideo
27
Oranienberg
35
Braenderup
25
Source: Illinois Department of Public Health
Table 10. Frequency of Salmonella Serotypes in Illinois, 1998-2006
Serotype
Aberdeen
Abony
Adelaide
Agbeny
Agona
Agoueve
Alachua
Albany
Amsterdam
Anatum
Antsalova
Apapa
Arizonae
Austin
Baildon
Bareilly
Barranquilla
Beaudesert
Berta
Bledgam
Blockley
Bonariensi
Bonn
Bovis-morb
Braenderup
Brandenburg
1998
0
0
2
0
129
0
1
0
10
0
0
0
0
3
4
0
0
7
0
3
1
1
11
32
10
1999
0
0
3
0
48
0
1
2
0
7
0
0
1
0
0
6
0
0
9
0
4
1
0
5
28
5
2000
1
0
1
0
27
0
2
0
0
9
0
0
4
1
0
5
0
0
25
0
5
0
0
7
18
5
2001
2002
0
0
4
0
14
0
0
1
0
10
0
0
2
0
0
7
0
0
41
0
1
1
0
3
16
9
0
0
0
0
20
0
1
0
0
9
0
0
3
0
1
5
0
1
19
0
3
1
0
2
21
2
158
2003
0
0
6
0
16
0
1
0
0
15
0
0
1
0
2
1
0
0
23
0
2
0
0
7
32
12
2004
0
0
5
0
22
0
0
1
0
18
1
1
2
0
0
1
0
0
19
0
0
0
0
3
79
2
2005
1
0
9
0
33
0
0
2
2
13
0
0
2
0
1
6
0
0
17
0
2
0
0
2
36
14
2006
0
1
5
1
29
1
1
1
1
15
0
0
4
0
0
5
2
0
17
1
2
0
0
5
25
8
Bredeney
Carmel
Carrau
Cerro
Chailey
Chameleon
Chester
Cholerae-suis
Coeln
Serotype
Colindale
Concord
Corvallis
Cotham
Cubana
Derby
Dublin
Durban
Durham
Ealing
Eastbourne
Edinburg
Emek
Enteritidis
Finkenwerd
Flint
Fluntern
Freetown
Gaminara
Give
Grumpensis
Guinea
Haardt
Hadar
Haifa
Hartford
Havana
Heidelberg
Herston
Hull
Hvittingfoss
Ibadan
Indiana
Infantis
Inverness
Irumu
Jangwani
Java
Javiana
Johannesburg
Kentucky
Kiambu
3
0
0
0
2
0
1
3
0
1998
1
0
0
0
2
13
0
0
1
0
1
0
0
405
0
1
0
0
0
5
0
0
0
40
0
12
1
115
0
0
2
0
0
65
0
0
0
37
11
4
0
0
0
0
0
0
0
1
3
7
0
1999
0
0
0
0
0
14
0
0
0
1
1
0
1
264
1
2
0
0
1
4
0
0
0
15
0
16
2
101
0
0
1
0
2
51
1
0
0
41
27
6
4
1
0
0
0
1
2
1
3
4
0
2000
0
0
0
0
1
14
0
0
0
0
1
0
0
262
0
0
0
0
0
1
0
0
0
26
1
18
2
101
0
1
3
0
0
38
0
0
0
35
24
3
1
2
2
0
0
0
0
0
6
2
0
2001
1
0
0
0
0
1
1
1
0
2002
2
0
0
0
2
9
0
0
1
0
0
0
0
246
0
1
0
0
2
1
0
0
1
8
0
15
1
66
0
0
1
0
0
35
0
0
0
24
17
3
3
2
0
0
0
0
1
14
1
0
1
0
0
0
0
376
0
0
0
0
1
7
0
0
0
16
0
22
2
171
1
0
4
0
2
30
2
0
1
7
19
1
1
5
159
4
0
0
0
0
0
2
2
0
2003
0
0
0
1
0
5
0
0
0
0
0
3
2
207
0
0
0
1
2
2
0
1
0
18
0
9
1
113
0
0
0
0
0
130
0
1
0
1
263
0
2
1
2
2
0
2
1
0
0
2
0
2004
1
0
0
0
1
10
2
3
0
0
0
2
0
236
0
0
1
3
0
3
0
0
1
16
0
9
4
79
0
0
2
0
0
96
1
0
0
0
24
0
1
1
2
0
1
2
0
0
0
1
0
2005
0
0
0
1
0
16
4
0
0
0
2
4
0
325
0
0
0
1
0
5
5
0
1
8
0
9
2
93
0
0
0
0
1
35
0
0
0
9
16
2
2
2
1
0
1
0
0
0
1
1
1
2006
0
1
1
1
0
16
2
0
0
2
1
0
2
309
0
0
1
0
2
2
0
0
0
19
2
20
1
80
0
1
1
2
0
30
1
0
0
8
11
3
0
3
Kingabwa
Kintambo
Kottbus
Kua
Limete
Lindern
Litchfield
Livingstone
Lomalinda
Serotype
Lomita
London
Manhattan
Marina
Matadi
Mbandaka
Meleagridis
Miami
Mikawasim
Minnesota
Mississippi
Molade
Monschaui
Montevideo
Muenchen
Muenster
Nagoya
Napoli
New-brunswick
Newington
Newport
Nima
Norwich
Oakland
Ohio
Onderstepoort
Oranienberg
Oranienberg var
14+
Orientalis
Orion
Oslo
Panama
Paratyphi a
Paratyphi b
Paratyphi c
Parera
Pensacola
Poano
Pomona
Poona
Putten
0
0
0
0
0
0
7
0
0
0
4
15
3
0
2
3
3
0
0
2
0
0
62
31
10
0
0
0
2
71
1
0
0
7
1
26
0
0
0
0
0
0
0
10
0
0
1999
0
3
4
2
0
10
0
4
0
0
3
0
0
56
36
1
0
0
1
3
59
0
4
0
3
0
21
0
0
0
1
3
11
1
0
0
0
0
11
18
1
0
0
5
3
1
1
0
0
0
1
0
19
1
1998
0
0
0
0
0
0
9
0
2
0
4
8
3
0
7
0
2
0
3
3
0
1
35
32
3
0
0
1
0
85
1
6
0
0
0
24
0
0
0
4
3
0
7
0
4
1
3
0
0
0
16
42
2
0
1
0
0
121
2
2
0
6
0
28
0
0
1
3
2
0
5
0
2
0
0
0
0
2
21
32
1
0
0
0
0
121
1
2
0
2
0
37
0
0
0
0
0
0
0
13
1
0
2003
0
3
1
3
2
6
2
4
0
0
1
1
1
27
45
1
1
0
0
1
151
0
3
1
1
1
30
0
0
0
1
2
11
1
0
0
0
0
0
16
0
0
0
1
9
2
0
1
0
0
0
0
12
0
0
1
2
11
9
1
0
0
0
0
0
6
0
0
0
2
3
18
5
0
0
0
1
3
7
0
2000
1
1
2
1
0
0
9
1
0
2001
0
0
0
1
0
0
7
1
9
2002
160
0
0
1
0
0
0
8
0
0
2004
0
0
1
0
0
1
5
0
1
2005
0
1
0
0
1
0
5
0
0
2006
1
4
4
2
0
6
0
1
1
2
5
0
0
48
34
1
0
1
0
0
94
0
5
0
23
0
26
0
0
1
2
0
0
9
1
2
0
7
3
0
1
41
32
5
1
0
0
0
68
0
0
0
0
0
27
0
0
4
2
0
0
24
3
1
0
3
4
0
2
27
30
3
0
0
0
0
131
0
2
0
5
0
33
2
1
0
0
5
4
18
0
1
1
0
3
12
0
0
0
1
8
7
8
2
0
1
0
6
7
1
0
0
1
11
14
11
0
0
0
0
1
9
0
Reading
Richmond
Rissen
Roodepoor
Roterberg
Rubislaw
San-diego
Saint-paul
Saphra
Serotype
Schwarzengrund
Senftenberg
Shubra
Simi
Singapore
Soahamina
Stanley
Stanleyville
Sundsvall
Takoradi
Tallahassee
Telelkebir
Tennessee
Thompson
Tilene
Typhimurium
Typhimurium
var.Copenhagen
Uganda
Urbana
Utah
Virchow
Wandsworth
Wangata
Wassenaar
Waycross
Weltevreden
Worthington
I rough:d:l,w
I rough:e,h:
e,n,z,15
I rough:r:1,5
I rough:
nonmotile
I 4,5,12:b:II rough:b:e,n,
x,z15
IIIa
13,22:z4z23:Monophasic, I
4,12,i
I 4,12,:H to
rough to type
6
0
0
1
1
2
1
30
0
1998
4
8
0
0
0
0
7
0
1
0
0
0
3
34
0
405
0
2
0
0
0
0
0
0
21
0
1999
7
13
0
0
0
0
12
1
0
0
0
1
2
30
0
354
0
6
0
1
0
0
1
3
28
0
2000
3
9
0
0
2
0
5
0
0
0
0
2
0
36
0
350
0
4
0
2
0
0
1
1
22
0
2001
1
12
0
1
0
0
4
0
0
1
0
0
2
24
0
285
0
5
1
1
0
0
1
5
37
1
2002
5
8
0
0
0
0
9
0
1
0
0
0
4
24
0
314
0
5
0
2
0
0
1
4
27
0
2003
9
2
0
0
0
0
12
0
0
1
0
2
8
30
0
373
0
7
0
0
0
0
3
11
50
0
2004
6
1
0
0
1
0
10
0
0
0
0
2
5
35
1
274
0
4
1
1
0
0
1
4
28
1
2005
11
10
1
0
0
2
15
2
0
0
0
1
6
33
0
376
2
0
1
1
0
0
0
9
15
0
2006
10
4
0
0
1
0
11
0
0
0
1
1
18
24
0
303
0
6
5
0
1
0
0
0
0
5
2
0
0
5
7
0
8
0
0
0
0
3
1
0
0
8
2
0
2
0
2
1
0
0
1
0
0
15
2
0
4
1
1
0
0
2
0
0
0
5
2
0
3
0
0
2
0
1
0
0
0
3
0
1
11
0
0
0
2
3
15
0
0
2
4
0
8
0
0
0
0
4
1
0
0
2
2
0
4
0
0
0
0
3
0
0
0
4
1
0
4
0
0
0
0
3
4
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
1
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
161
I 4,5: nonmotile
Monophasic,
4,5,12:b
Monophasic,
other
Non-motile
Other
Too rough
Untyped
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
42
1
13
0
0
0
0
0
0
0
0
60
0
0
0
158
0
0
0
152
0
0
0
123
0
0
0
156
0
3
0
271
0
24
0
228
0
8
0
117
0
7
6
272
3
16
1
101
Table 11. Twelve Serotypes and Exposure Location, 2006
Serotype
Exposed in Illinois
#
%
Exposed in another state
#
%
Exposed outside of the U.S.
#
%
Agona
15
71
2
9
4
Braenderup
17
94
0
0
1
6
162
72
8
4
54
24
97
1
1
1
1
0
0
0
0
Enteritidis
19
Heidelberg
65
Infantis
21
Montevideo
19
86
1
4
2
9
Muenchen
21
87
1
4
2
8
Newport
96
96
3
3
1
1
Oranienberg
20
87
0
0
3
4
Paratyphi A
1
9
0
0
Paratyphi B
4
0
0
8
4
Typhimurium
182
100
100
89
162
10
0
13
91
0
6
Sexually Transmitted Diseases
Included in this section are three diseases - chlamydia, gonorrhea and syphilis transmitted primarily or exclusively through sexual contact and reportable under Illinois
statutes and administrative rules. Other diseases not included in this section (such as
herpes and human papilloma virus) may be transmitted sexually. HIV/AIDS is discussed
in a separate section.
The control of sexually transmitted diseases (STDs) is an important strategy for
the prevention of HIV. The inflammation and lesions associated with STDs increase an
individual’s risk for acquisition of HIV, as well as the ability to transmit HIV to others.
Chlamydia
Background
Chlamydia trachomatis infection is a significant cause of genitourinary
complications, especially in women. Early symptoms of cervicitis or urethritis are mild;
asymptomatic infection is common in both women and men. If left untreated, chlamydia
infection can lead to pelvic inflammatory disease in women. It may cause severe
fallopian tube inflammation and damage, even though symptoms may be mild. Due to
the insidious nature of the infection, C. trachomatis is a major cause of long-term
sequelae such as tubal infertility and ectopic pregnancy and can cause premature
rupture of membranes in pregnant women. Chlamydia also can cause ophthalmia and
pneumonia in newborns exposed to it during birth.
Chlamydia is reportable in all but one state. During 2006, more than one million
chlamydia infections were reported to the CDC, making chlamydia the most commonly
reported notifiable disease in the United States. However, national data are incomplete
because the majority of testing currently is conducted in females.
Federal and state funding for chlamydia is targeted at providing screening
programs in STD clinics, women’s health programs (such as family planning and
prenatal clinics), and in adult and juvenile correctional centers.
Case definition
The case definition is isolation of C. trachomatis by culture, or demonstration of
C. trachomatis in a clinical specimen by detection of antigen or nucleic acid.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 53,586; the overall incidence rate was
431 per 100,000 population. The number of cases increased by 84 percent from
1997 (9,184) to 2006 (53,586) (Figure 86).
• Age - Adolescents and young adults (ages 15 to 24) accounted for 34 percent of
reported chlamydia cases in 2006 (Figure 87). The average age of persons reported
with chlamydia was 23.
• Gender - The female-to-male ratio of reported cases was 2.9 : 1.0.
• Race/ethnicity - The racial/ethnic distribution of cases was non-hispanic African
American (53 percent), non-hispanic white (19 percent), non-hispanic Asian/Pacific
Islander (1 percent), hispanic (10 percent) and other or unknown (17 percent).
163
•
Geographic distribution - Chlamydia is geographically distributed throughout the
state. Cases were reported from all 102 counties. The five counties with the highest
incidence rates per 100,000 were Pope (1,360), Peoria (860), St. Clair (743),
Alexander (699) and Jackson (690).
Summary
Chlamydia is the most commonly reported sexually transmitted disease in Illinois.
Cases were reported from all counties in Illinois during 2006. Adolescents and young
adults had the highest incidence rates. Reasons for the increase in cases from 1993 to
2006 include increased testing, improved surveillance, and the use of more sensitive
diagnostic tests.
Number of cases
Figure 86. Chlamydia Cases in Illinois, 2001-2006
60000
48101
43716
48294
53586
50559
47185
40000
20000
0
2001
2002
2003
2004
2005
2006
Year
Incidence pepr
100,000
Figure 87. Age Distribution of Chlamydia Cases in Illinois, 2006
2500
2000
1500
1000
500
0
0-4
5-9 yr
10-14
yr
15-1 9
yr
20-24
yr
25-29
yr
30-34
yr
Year
164
35-39
yr
40-44
yr
45-54
yr
55-64
yr
65 + yr
Gonorrhea
Background
Gonorrhea is a bacterial infection caused by Neisseria gonorrhoeae.
Uncomplicated urogenital infection may progress, without treatment, to complications
such as infertility, pelvic inflammatory disease (PID) and disseminated infection.
Resultant scarring of fallopian tubes may result in ectopic pregnancy. Women are more
likely than men to suffer complications from gonorrhea infection because early
symptoms are often not present or not recognized in females. Infants born to infected
mothers may develop gonococcal ophthalmia, which is potentially blinding, or sepsis,
arthritis or meningitis.The United States recorded 358,366 cases of gonorrhea in 2006.
Currently recommended therapies for gonorrhea are highly effective, although
antimicrobial drug resistance has been a problem. Gonococcal susceptibility to some
currently recommended drugs is gradually declining, and active surveillance is required
to monitor resistance and to ensure the effectiveness of therapy. An increase in
resistance to quinolones occurred in 2006.
This was the second consecutive year with an increase in cases.
Case definition
Isolation of typical gram-negative, oxidase positive diplococci (presumptive
Neisseria gonorrhoeae) from a clinical specimen; demonstration of N. gonorrhoeae in a
clinical specimen by detection of antigen or nucleic acid; or observation of gramnegative intracellular diplococci in a urethral smear obtained from a male urethral or
female endocervical smear.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 20,186; case rate was 162 per
100,000 population. Reported cases in 2006 were higher by 1 percent than the
number reported in 2005 (Figure 88). Gonorrhea is the second most commonly
reported STD in Illinois.
• Age - Adolescents and young adults are at greatest risk for gonorrhea infection.
Persons aged 15 to 24 accounted for 60 percent of reported cases in 2006 (Figure
89). The average age of cases was 25.
• Gender – The ratio of reported female to male cases was 1.2: 1.0.
• Race/ethnicity - Illinois minorities are disproportionately affected by gonorrhea. The
reported cases were 71 percent non-Hispanic African American, 21 percent nonHispanic white, 3 percent Hispanic and 14 percent other or unknown race.
• Geographic distribution - At least one case of gonorrhea was reported in 89 Illinois
counties. The five counties with the highest incidence rate in 2006 were Macon
(465), Peoria (436), Sangamon (380), St. Clair (329) and Pulaski (286).
Summary
Gonorrhea is the second most commonly reported sexually transmitted disease
after chlamydia in Illinois. In 2006, 60 percent of gonorrhea cases in Illinois were in
those 15 to 24 years of age.
165
Number of cases
Figure 88. Gonorrhea Cases in Illinois, 2001-2006
30000
24025
24026
21817
20597
20019
20186
20000
10000
0
2001
2002
2003
2004
2005
2006
Year
Incidence
Figure 89. Age Distribution of Gonorrhea Cases in Illinois, 2006
8 00
6 00
4 00
2 00
0
0 -4
5 -9 y r
10-14
yrs
15-19
y rs
20 -24
yrs
25-2 9
yrs
30-34
yrs
Year
166
3 5-39
yrs
40- 44
yrs
45-5 4
yrs
55-64 65+ y rs
yrs
Syphilis
Background
Syphilis is a systemic disease caused by the spirochete Treponema pallidum.
The infection is definitively diagnosed through microscopic examination of lesion
exudates and presumptively through serologic testing. Without treatment, syphilis
infection progresses through four stages: primary, characterized by a painless ulcer at
the point at which the organism entered the body (genitals, mouth, anus); secondary,
characterized by lesions, rashes, hair loss, lymphadenopathy and/or flu-like symptoms;
latent with no signs or symptoms; and late symptomatic, in the form of neurosyphilis
(with neurologic damage) and tertiary (cardiovascular or gummatous disease).
The open lesions of syphilis are infectious to sex partners. Syphilis during
pregnancy can lead to a congenital form of the disease that may result in stillbirth or
severe illness and lifelong debilitating consequences for the infant. Increases in syphilis
often are associated with poverty, limited availability of health services and the
exchange of sex for drugs or money. Syphilis outbreaks are often a precursor of HIV
increases in affected populations because the lesions caused by syphilis increase the
likelihood of both acquisition and transmission of HIV. Without treatment, approximately
10 percent of persons with syphilis will develop neurosyphilis, but in persons co-infected
with HIV, 25 percent may develop neurosyphilis.
“Early syphilis” refers to syphilis infection of less than one year duration and
progresses through: primary, secondary and early latent. Public health disease
intervention efforts emphasize control of early syphilis because persons with this stage
of the disease are most likely to have been infectious within the past year. Many
individuals do not notice or recognize the symptoms of syphilis, so screening for latent
disease and partner notification and referral are important components of control efforts.
Congenital syphilis occurs when the syphilis organism is transmitted from a
pregnant woman to her fetus. Untreated syphilis during pregnancy can result in stillbirth,
neonatal death or infant disorders such as deafness, bone deformities, and neurologic
impairment.
Significant public health resources must be devoted to control of syphilis.
Untreated syphilis can result in neurological or cardiovascular complications. It also can
be transmitted to a fetus from an infected woman during pregnancy, which results in
congenital syphilis.
The CDC recorded 431 primary and secondary syphilis cases in the United
States in 2006. The rate of infection was 3.3 per 100,000 population. In 2006, a total of
349 cases of congenital syphilis were reported. The number of primary and secondary
cases increased for the sixth consecutive year. Sixty-four percent of cases were
reported from men who have sex with men.
Case definition
Syphilis is a complex disease with a highly variable clinical course. The following
case definitions are used for surveillance purposes for syphilis that has not progressed
to late symptomatic stages.
•
Primary. A clinically compatible case with one or more ulcers (chancres) consistent
167
with primary syphilis and a reactive serologic test; or demonstration of T. pallidum in
clinical specimens by dark field microscopy, fluorescent antibody or equivalent
methods.
•
•
Secondary. A clinically compatible case with a reactive nontreponemal test titer of >
1:4 (probable case), or demonstration of T. pallidum in clinical specimens by dark
field microscopy, fluorescent antibody or equivalent methods (confirmed case).
Latent. No clinical signs or symptoms of syphilis and the presence of one of the
following:
o No past diagnosis of syphilis, a reactive nontreponemal test and a reactive
treponemal test.
o A past history of syphilis therapy and a current nontreponemal test titer
demonstrating fourfold or greater increase from the last nontreponemal test
titer.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 - Sixteen congenital cases and 431
primary or secondary cases were reported (Figure 90). Primary and secondary
cases decreased 18 percent between 2005 and 2006. Congenital syphilis decreased
61 percent from 2002 to 2006. The incidence rate was 5.6 per 100,000 population
for primary and secondary syphilis and 8.9 per 100,000 live births for congenital
syphilis. Note: CDC summaries show 15 congenital syphilis cases reported from
Illinois in 2006. We will use 16 cases in this report.
• Age - The average age of persons diagnosed with primary and secondary syphilis is
34 years. Adults aged 30 and older accounted for 60 percent of primary and
secondary cases (Figure 91).
• Gender - Ninety-one percent of primary and secondary cases were male.
• Race/ethnicity - The proportion of primary and secondary syphilis cases by race
were non-hispanic white (38 percent), non-hispanic African American (44 percent),
hispanic (13 percent), and other or unknown races (5 percent).
• Geographic distribution - Syphilis is more prevalent in urban populations.The
disease has become progressively concentrated geographically. Cases of primary
and secondary syphilis were reported from 24 counties. The five highest incidence
rates per 100,000 population in counties with at least three cases were Vermilion
(3.6), Cook (6.5), Champaign (4.5), St. Clair (3.3) and Dupage (2.0). Four counties
reported congenital syphilis cases.
• Clinical presentation – During 2006, there were 34 cases of reported neurosyphilis;
(94 percent) of the 2006 cases were in men. Of the 32 males, 31 percent were
MSM. Thirty-seven percent of the primary and secondary cases were known to be
co-infected with HIV.
Summary
Primary and secondary syphilis cases decreased by 18 percent in 2006
compared to 2005. During 2006, white males and African American females were
disproportionately affected by syphilis.
168
Number of cases
Figure 90. Syphilis Cases in Illinois, 2001-2006
600
525
479
409
200
431
386
374
400
Primary and Secondary
Congenital
45
41
21
25
25
16
2001
2002
2003
2004
2005
2006
0
Year
Figure 91 . Age Distribution of Syphilis Cases in Illinois, 2006
Incidence
15
10
5
0
0-4 yrs 5-9 yr
10-14
y rs
15-19
yrs
20-2 4
yrs
25- 29
yrs
3 0-34
yrs
Yea r
169
35-39
y rs
40-44
yrs
45-5 4
yrs
55-6 4
yrs
65 +
yrs
Shigellosis
Background
Shigellosis is an acute bacterial disease of humans and non-human primates
caused by four species or serogroups of Shigella: S. dysenteriae (group A), S. flexneri
(group B), S. boydii (group C) and S. sonnei (group D). The infectious dose is low; as
few as 10 to 100 bacteria can cause infection. Transmission is via direct or indirect
fecal-oral routes. Outbreaks in day care centers are not uncommon and Shigella can be
transmitted through unchlorinated wading pools, interactive water fountains, food items
such as parsley and bean dip and between men who have sex with men. The
incubation period is usually one to three days. Symptoms of the disease are watery or
bloody diarrhea with fever and sometimes vomiting or tenesmus. Mild and
asymptomatic infections can occur. Duration of illness is usually from four to seven
days. Shigella can be shed in stool for four weeks. Disease caused by Shigella
dysenteriae type 1 is the most severe and can cause hemolytic uremic syndrome (HUS)
due to a toxin similar to that produced by E. coli O157:H7. Antimotility drugs are
contraindicated. Antimicrobial therapy can limit the clinical course and duration of fecal
excretion of Shigella. Shigella can develop antimicrobial resistance quickly.
The subgroups, serotypes and subtypes of Shigella are:
Group A: Shigella dysenteriae
15 serotypes (type 1 produces Shiga toxin)
Group B: Shigella flexneri
8 serotypes and 9 subtypes
Group C: Shigella boydii
19 serotypes
Group D: Shigella sonnei
1 serotype
Of the ten diseases/syndromes (caused by Campylobacter, Cryptosporidium,
Cyclospora, HUS, E. coli O157:H7, Listeria monocytogenes, Salmonella, Shigella,
Vibrio and Yersinia enterocolitica) under active surveillance in the federal FoodNet sites,
Shigella comprised 2,736 of 17,252 (16 percent) of the reported infections in 2006 in
preliminary data. The incidence rate overall was six per 100,000 for shigellosis and
ranged from 0.9 to 15 at the 10 FoodNet sites for preliminary 2006 data. The number of
Shigella infections decreased from baseline by 35 percent in 2006 at these sites.
In 2006, 15,503 Shigella cases were reported to CDC. S. sonnei accounts for
more than 75 percent of shigellosis cases in the United States. In 2002, from six states
reporting nationally to CDC, the median time from onset of symptoms to PFGE typing
was 21 days. The median interval from onset of illness to interview of patient was 14
days.
Multi-community outbreaks of shigellosis require extensive time and effort on the
part of public health. Because of the low infectious dose, shigellosis spreads quickly
between people when breaches in handwashing or sanitation occur. Propagation of
shigellosis is increased because of the difficulty in maintaining handwashing and
sanitation in day care centers, high proportion of mild or asymptomatic Shigella
infections and frequent contact between children who attend multiple day care centers.
Interventions include alerting the media to the outbreak, direct communication with day
care centers and the medical community, and promoting control strategies such as
supervised handwashing and exclusion of symptomatic children from day care.
However, strict exclusion policies of infected but asymptomatic children can lead to
spread of an outbreak if excluded day care attendees are then placed in alternative
170
child care settings.
Case definition
The case definition for a confirmed case of shigellosis in Illinois is a case from
which Shigella is isolated from a clinical specimen. The case definition for a probable
case is a person who has a clinically compatible illness that is epidemiologically linked
to a confirmed case, but is not laboratory confirmed.
Descriptive epidemiology
• Number of reported cases in Illinois in 2006 - There were 720 cases reported
(five-year median = 630; see Figure 92). Overall annual incidence rate was six
per 100,000. Of the cases, 628 were confirmed and 92 were probable.
• Age – The mean age of cases was 40 years (Figure 93). By age group, annual
incidence rates per 100,000 were: less than 1 year old (eight); 1 to 4 years of age
(28); 5 to 9 years of age (16); 10 to 19 years of age, (four); 20 to 29 years of
age, (five); 30 to 59 years of age (two); and 60 and older (one).
• Gender – Fifty-two percent were female.
• Race/ethnicity – Fifty-four percent were white, 33 percent were African American,
and 13 percent were other races; 37 percent were Hispanic. There were
significantly higher proportions of Hispanics with shigellosis (37 percent)
compared to their representations in the Illinois population (12 percent).
• Geographic distribution – For 2006, counties with the highest incidence per
100,000 were Morgan (309), Kankakee (79), St. Clair (20), Scott (18) and Adams
(18). Figure 94 shows county incidence for the state.
• Clinical syndrome – Symptoms reported included diarrhea (98 percent), fever (70
percent) and vomiting (48 percent).
• Outcome – Thirty-two percent of cases were hospitalized. No fatalities were
reported.
• Seasonal variation - Shigellosis cases occurred in all months of the year with a
peak in the month of August (Figure 95).
• Serotypes - Ninety-five percent of isolates were serotyped in 2006. The most
common species was S. sonnei (86 percent of typed isolates), followed by S.
flexneri (13 percent). S. boydii and S. dysenteriae each made up less than one
percent of typed isolates. The boydii serotypes found in Illinois were 1, 2 and 12,
and the dysenteriae serotypes were 2 and 3 (Table 12 and 13). The three most
common S. flexneri serotypes were 2 (23 cases), 3 (14 cases), and 1 (13 cases)
(Table 14). S. sonnei does not have subtypes, but there were 584 S. sonnei
cases reported.
• Reporter – Fifty-four percent were reported by infection control professionals and
41 percent by laboratories.
• Risk factors
o Fifty-one cases acquired infection in another country. Mexico was the
most frequent country where acquisition occurred (23, 45 percent).
o Ten cases acquired infection in another state. The most frequent state
mentioned was Florida (three cases).
171
•
•
•
o Twenty-four of 521 (5 percent) reported swimming in non-chlorinated
water, and 47 of 510 (9 percent) swam in chlorinated water.
o Forty-four cases attended day care and four attended a residential facility.
o Of 573 cases, 163 (28 percent) reported contact with someone attending a
day care center. Seventy-three of 531 cases (14 percent) reported contact
with someone in a residential facility.
o One person of 394 reported drinking water from a well.
Sensitive occupations – Cases were employed in the following sensitive
occupations: day care (nine), food service (eight), health care (six), residential
facility (two), and other sensitive occupations (10).
Foodborne outbreaks – There were no foodborne outbreaks of shigellosis in
2006.
Person-to-person outbreaks – Five person-to-person outbreaks were reported.
See non-foodborne, non-waterborne section for details.
Summary
There was an increase in Shigella cases from 2005 to 2006. The incidence rate
for 2006 of six per 100,000 is within the range reported at CDC’s FoodNet sites. The
proportion who were Hispanic was higher than the representation of hispanics in the
Illinois population. The mean age of cases was 40 years. Ninety-five percent of isolates
were serotyped. S. sonnei was the most common serotype found in Illinois, which is the
same as the most common serotype identified in CDC’s FoodNet sites. Isolates of
Shigella are required to be submitted to the Department’s laboratories for speciation
and/or serotyping (if this cannot be done by the clinical laboratory).
Suggested readings
Hedberg, C.W. et al. Timeliness of enteric disease surveillance in 6 US states.
Emerg Infect Dis [serial on the Internet]. 2008 Feb. Available from
http://www.cdc.gov/EID/content/14/2/311
Number of cases
Figure 92. Shigella Cases in Illinois, 2001-2006
1500
1000
1105
1006
720
630
402
500
409
0
2001
2002
2003
2004
Year
172
2005
2006
Figure 93. Age Distribution of Shigella Cases in Illinois, 2006
Incidence
40
30
Male
20
Fem ale
10
0
<1 y r
1- 4 yr
5-9 yr
10-1 9 yr 2 0-29 yr 30-3 9 yr 40 -49 yr 50-59 yr
>59 y r
Age category
Number of cases
Figure 94. Shigella Cases in Illinois by Month, 2006
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
173
Aug
Sep
Oct
Nov
Dec
Figure 95. Shigellosis Incidence Rates by County for Illinois, 2006
Jo Daviess
StephensonWinnebago McHenry Lake
Boone
Carroll
Ogle
DeKalb
Whiteside
Kane
DuPage Cook
Lee
Kendall
Will
Rock Island
Bureau
Henry
Mercer
La Salle
Stark
Kankakee
Marshall
Knox
Livingston
HendersonWarren
Woodford
Peoria
McLean
Mason
Schuyler
Brown
Menard
Cass
Vermilion
Champaign
De Witt
Logan
Piatt
Macon
Morgan
Pike
Iroquois
Ford
Tazewell
McDonough
Fulton
Hancock
Adams
Grundy
Putnam
Douglas
Sangamon
Scott
Christian
Coles
Shelby
Greene
Calhoun
Jersey
Edgar
Moultrie
Cumberland
Macoupin
Montgomery
Fayette
Effingham
Clark
Jasper Crawford
Bond
Madison
Clay
Marion
Clinton
St. Clair
RichlandLawrence
Wayne
Washington
Monroe
Randolph
Perry
Jefferson
Wabash
Edwards
HamiltonWhite
Franklin
Jackson
SalineGallatin
Williamson
Union
Hardin
Johnson
Pope
AlexanderPulaski Massac
Source: Illinois Department of Public Health
174
175
Table 12. Frequency of Shigella boydii in Illinois, 1999-2006
Type
1999 2000 2001 2002 2003 2004 2005 2006
boydii, unknown
0
0
0
0
0
0
0
0
boydii 1
0
0
2
0
0
0
0
1
boydii 2
4
4
3
1
5
1
1
1
boydii 3
0
0
0
1
0
0
0
0
boydii 4
7
2
0
2
2
1
1
0
boydii 5
0
1
0
0
0
0
0
0
boydii 8
0
0
0
0
0
2
0
0
boydii 10
1
0
0
0
0
0
0
0
boydii 11
0
1
0
0
0
0
0
0
boydii 12
1
0
0
0
0
0
0
1
boydii 13
0
1
0
0
0
0
0
0
boydii 14
2
2
1
2
1
0
0
0
boydii 18
4
1
0
0
0
1
0
0
boydii 19
0
0
0
0
0
0
0
0
boydii 20
0
0
0
0
0
1
0
0
19
12
6
3
8
6
2
3
TOTAL boydii
Source: Illinois Department of Public Health
Table 13. Frequency of Shigella dysenteriae in Illinois, 1999-2006
Type
1999 2000 2001 2002 2003 2004 2005 2006
dysenteriae,
unknown
0
2
0
0
1
1
0
1
dysenteriae 1
1
0
0
0
0
1
0
0
dysenteriae 2
4
0
0
0
2
0
0
1
dysenteriae 3
0
0
0
1
0
1
0
1
dysenteriae 4
0
0
0
1
0
0
3
0
dysenteriae 9
0
0
0
0
0
0
0
0
dysenteriae 12
0
0
0
0
0
0
0
0
TOTAL
dysenteriae
5
2
0
2
3
3
3
3
176
Source: Illinois Department of Public Health
Table 14. Frequency of Shigella flexneri subtypes in Illinois, 1999-2006
Type
1999 2000 2001 2002 2003 2004 2005 2006
flexneri, unknown
39
31
24
14
15
14
11
21
flexneri 1
11
3
5
8
9
8
11
13
flexneri 1A
0
0
0
0
0
0
0
0
flexneri 1B
1
0
0
0
0
0
0
1
64
49
23
36
33
36
29
23
flexneri 2A
1
0
0
0
1
0
0
0
flexneri 2B
0
0
0
1
0
1
0
0
24
27
14
7
29
7
14
14
flexneri 3A
0
0
0
0
0
0
0
3
flexneri 3B
0
0
0
0
0
0
0
1
15
10
11
23
11
23
7
11
flexneri 4A
0
1
0
0
1
0
0
0
flexneri 4B
0
0
0
0
0
0
0
0
flexneri 5
0
0
0
0
0
0
0
0
flexneri 5A
0
0
0
0
0
0
0
0
11
8
9
8
7
8
0
3
flexneri X variant
0
0
0
1
1
1
2
0
flexneri Y variant
0
1
3
1
0
1
5
2
166
130
89
99
107
99
79
92
flexneri 2
flexneri 3
flexneri 4
flexneri 6
TOTAL flexneri
Source: Illinois Department of Public Health
177
Staphylococcus aureus, Intermediate or High Level Vancomycin
Resistance
Background
Staphylococcus aureus causes both community and health care associated
infections in persons. The National Committee for Clinical Laboratory Standards
(NCCLS) defines staphylococci requiring concentrations of vancomycin of < 4 ug/mL for
growth inhibition as susceptible to vancomycin. Those requiring concentrations of eight
to 16 ug/mL as intermediate and those requiring concentrations of at least 32 ug/mL as
resistant. S. aureus with reduced vancomycin susceptibility (SA-RVS) includes all S.
aureus isolates with MICS of vancomycin of at least four ug/mL.
Three cases of SA-RVS have been identified in Illinois, two in 1999 and one in
2000.
Case definition
A case of S. aureus, intermediate or high level vancomycin resistance is defined
as S. aureus isolated from infected humans with an MIC of vancomycin of at least four
ug/mL.
Descriptive epidemiology
No cases were reported in 2006.
Summary
No cases were reported in 2006 in Illinois.
178
Streptococcus pyogenes, Group A (Invasive Disease)
Background
The spectrum of disease caused by group A streptococci (GAS) is diverse and
includes pharyngitis and pyoderma, severe invasive infections, post-streptococcal acute
rheumatic fever and acute glomerulonephritis. Invasive GAS may present as any of
several clinical syndromes including pneumonia, bacteremia in association with
cutaneous infection (cellulitis, erysipelas or infection of a surgical or nonsurgical
wound), deep soft tissue infection (myositis or necrotizing fasciitis), meningitis,
peritonitis, osteomyelitis, septic arthritis, postpartum sepsis (puerperal fever), neonatal
sepsis and non-focal bacteremia. Two types of invasive GAS are streptococcal toxic
shock syndrome (STSS) and necrotizing fasciitis. The symptoms of STSS include fever,
myalgia, vomiting, diarrhea, confusion, soft tissue swelling, renal dysfunction,
respiratory distress and shock. Necrotizing fasciitis is a deep infection of subcutaneous
tissue that results in destruction of fat and fascia and often leads to systemic illness.
Risk factors for necrotizing fasciitis include injection drug use, obesity and diabetes
mellitus.
Transmission of GAS occurs by direct contact with patients or carriers, or by
inhalation of large respiratory droplets. Approximately 5 percent of the population may
be asymptomatic carriers, but these individuals are less likely to transmit the organism
than symptomatic persons. Predisposing risk factors for invasive GAS include older
age, injection drug use, human immunodeficiency infection, diabetes, cancer, alcohol
abuse, varicella, penetrating injuries, surgical procedures, childbirth, blunt trauma, and
muscle strain. Treatment guidelines have been established by the Infectious Diseases
Society for GAS pharyngitis. Chemoprophylaxis is not recommended for all household
contacts to cases of invasive GAS. Household members should monitor themselves for
signs and symptoms for 30 days after exposure.
During 2006, 1,146 cases of invasive GAS were reported from the Active
Bacterial Core Surveillance site projects in 10 states. Incidence was highest in adults
greater than 64 years (10 cases per 100,000), children younger than 1 year of age (5.1
cases per 100,000) and 50 to 64 year olds (5.0 per 100,000). STSS accounted for 5
percent, and necrotizing fasciitis accounted for 7 percent of cases. The overall case
fatality rate was 14 percent.
In routine surveillance, 5,407 cases of invasive GAS were reported to CDC and
125 cases of streptococcal TSS.
Case definition
The case definition of invasive GAS disease in Illinois is the isolation of group A
Streptococcus pyogenes by culture from a normally sterile site.
Descriptive epidemiology
• Number of reported cases in Illinois in 2006 – There were 326 invasive GAS cases
including nine necrotizing fasciitis and 19 streptococcal toxic-shock syndrome
cases (five-year median = 326) (see Figure 96). All cases were confirmed. The
incidence rate for 2006 was three per 100,000 population.
• Age - Mean age was 51 (Figure 97). By age group, the highest incidence per
179
•
•
•
•
•
•
•
•
100,000 occurred in those older than 79 years of age (14 per 100,000 in that age
group), followed by those 70 to 79 years of age (7.5 per 100,000) and 60 to 69
years of age (5.6 per 100,000). At least 39 cases were residents of residential
institutions.
Gender – Fifty-one percent were male.
Race/ethnicity - Cases were 71 percent white, 17 percent African American and 7
percent other races; 14 percent occurred among Hispanics.
Geographic distribution – Forty-five percent of cases were residents of Cook
County. Cases were reported from 46 counties.
Seasonal variation - An increase in cases occurred from January to March (Figure
98).
Positive cultures - The number of positive cultures by type of specimen were blood 270 (83 percent of all cultures), unspecified tissue - 10 (3 percent), synovial fluid nine (3 percent), blood plus other source – 21 (6 percent), other – 12 (4 percent)
and unknown – four (1 percent).
Outcome – Ninety-five percent were hospitalized. Twenty-nine of 198 cases were
fatal (overall case fatality rate - 15 percent). Seventy–six percent of the fatalities
were in those older than 49 years of age (mean = 60 years). The highest fatality
rate occurred in those with toxic shock syndrome (71 percent), followed by
necrotizing fasciitis (25 percent) and invasive GAS only (10 percent).
Reporting – Seventy-seven percent were reported by infection control
professionals, and 21 percent were reported by laboratories.
Clusters – Two clusters were reported. See non-foodborne, non-waterborne
outbreak section for details.
Summary
The number of reported invasive GAS cases continues to rise in Illinois. The
highest incidence was in those older than 79 years of age. Seventy-six percent of the
fatalities were persons older than 49 years of age. Illinois had the second highest
number of streptococcal toxic shock cases reported in the United States.
Number of cases
Figure 96. Invasive GAS Cases in Illinois, 2001-2006
500
400
300
200
100
0
417
272
2001
326
2002
284
2003
2004
Ye ar
180
342
2005
326
2006
Incidence
Figure 97. Invasive GAS and Streptococcal TSS Cases by Age in
Illinois, 2006
13.6
15
10
5
3
0.7
1
2.3
3.2
0.2
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
2
7.5
5.6
0
0-4 yr
5-9 yr
60-69 yr
70-79 yr
80+
Age Group
Number of cases
Figure 98. Invasive GAS and Streptococcal TSS Cases in Illinois by
Month, 2006
60
40
20
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
181
Aug
Sep
Oct
Nov
Dec
S. pneumoniae
Background
S. pneumoniae is the most common cause of meningitis, community-acquired
pneumonia and bacteremia, and acute otitis media. Pneumococci colonize the
nasopharynx of 15 percent to 60 percent of individuals; most remain asymptomatic.
Carriage is higher in children attending child care centers outside the home. The onset
of S. pneumoniae meningitis is usually sudden with high fever, lethargy and signs of
meningeal irritation. It is a sporadic disease in the elderly and in young infants.
In the nine states which are part of the Active Bacterial Core Surveillance,
isolates were collected in 2006, 15 percent exhibited intermediate resistance to
penicillin, and 10 percent were fully resistant.
The pneumococcal conjugate 7-valent vaccine (6B, 14, 18C, 19F, 23F, 9V, 4)
was licensed in the United States in February 2000 and can be used in children younger
than 2 years of age. The vaccine protects against the seven strains of pneumococcus
that cause 80 percent of the invasive disease among children in the United States.
Individuals at the extremes of age and in certain ethnic groups (African
American, American Indians and Alaskan natives) are disproportionately affected.
Males are at higher risk for S. pneumoniae. Other risk factors for invasive disease
include renal dysfunction, sickle cell disease, alcoholism, smoking, HIV, organ
transplantation and diabetes mellitus.
In data for 2006 from the national Behavioral Risk Factor Surveillance system,
the percent of persons older than the age of 64 who had received at least one
pneumococcal vaccination was 60 percent.
The Healthy People 2010 objectives are to reduce invasive pneumococcal
disease to 46 per 100,000 in children younger than five years and to 42 per 100,000 in
adults aged 65 years or older. Since vaccine has been available incidence has declined.
Case definition
A case is defined as a person with clinically compatible symptoms and from
whom isolation of the organism from a normally sterile site has occurred. In INEDSS,
cases with MMWR year of 2006 were chosen for the information reported below. This
includes all invasive S. pneumoniae. CDC only required reporting of some S.
pneumoniae cases so their numbers will not match the numbers below.
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – 1,150 (five-year median = 936) (See
Figure 99). The incidence rate for 2006 was 9.2 per 100,000. CDC recorded 33
drug resistant cases from Illinois and 106 non drug resistant cases in children less
than five years. Information provided below is for 1,150 cases.
• Age - Mean age of cases was 55 years (see Figure 100 for age distribution).
• Gender – Fifty-two percent were female.
• Race/ethnicity - Twenty-two percent were African American, 74 percent were white
and 3 percent were other races; Eight percent were Hispanic.
• Seasonal peak – An increase in cases occurred in the winter and spring months
182
•
(Figure 101).
Clinical - Ninety-one percent of cases were hospitalized. Nine percent of cases
were fatal.
Summary
More than one thousand cases of invasive S. pneumoniae were reported in
Illinois in 2006.
Suggested readings
CDC. 2007: Active bacterial core surveillance report, Emerging Infections
Program Network, Streptococcus pneumonia, 2006. Available at:
www.cdc.gov/ncidod/dbmd/abcs/survreports/spneum06.pdf
Grijalva, C.G., et.al. Pneumonia hospitalizations among young children before
and after introduction of pneumococcal conjugate vaccine-United States, 1997-2006.
MMWR 58(1):1-4.
Kilmer, G., et. al. Surveillance of certain health behaviors and conditions among
states and selected local areas – Behavioral risk factor surveillance system (BRFSS),
United States, 2006. MMWR 2008; 57(SS-7):p.59.
Wooten, K.G. et al. National, state and local area vaccination coverage among
children aged 19-35 months-United States, 2006. MMWR 2007;56(34): 880-5.
Number of cases
Figure 99. S. pneumoniae Cases in Illinois, 2001-2006
1500
1226
1012
823
1000
1150
936
491
500
0
2001
2002
2003
2004
2005
Year
Incidence per 100,000
Figure 100 . S. pneumoniae Cases by Age in Illinois, 2006
40
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
Age group
183
30-59 yr
>59 yr
2006
Number of cases
Figure 101 . S. pneumoniae Cases in Illinois by Month, 2006
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
184
Aug
Sep
Oct
Nov
Dec
Tetanus
Background
Tetanus is non-communicable. Clostridium tetani spores can be present in the
environment and enter the body through nonintact skin. Generalized tetanus presents
with trismus (lockjaw) followed by generalized rigidity caued by contractions of the
skeletal muscles. Forty-one cases were reported in the United States in 2006. Mortality
was associated with underlying diabetes, IV drug use and advanced age.
Case definition
A confirmed case of tetanus is a clinically compatible case, as reported by a
health care professional.
Descriptive epidemiology
One case was reported in Illinois in October in an 81-year-old male from
Whiteside county. The patient was hospitalized for 24 days and on mechanical
ventilation. The patient had a wound from working in the yard on October 12 and
did not seek medical attention until symptoms of tetanus began on October 20.
His last dose of tetanus toxoid was nine years prior to onset.
185
Tickborne Diseases Found in Illinois
Number of
cases
Ticks are the most common vector of vectorborne diseases in the United States.
Ticks are responsible for the following diseases in the United States: babesiosis,
Colorado tick fever, human granulocytic ehrlichiosis, human monocytic ehrlichiosis,
Lyme disease, Powassan encephalitis, relapsing fever, Rocky Mountain spotted fever
(RMSF), tick paralysis and tularemia.
Ticks usually attach around the head, neck and groin of the human host. The
rates of human infection with tickborne diseases are influenced by the prevalence of
vector tick species, the tick infection rate, the readiness of ticks to feed on humans, and
the prevalence of their usual animal hosts.
Seven tickborne diseases have been reported in Illinois residents. Six of these
tickborne diseases are listed in Table 15 and in individual sections of this document. Six
cases of babesiosis have been reported in Illinois residents from 1991 through 2006
and all cases were acquired out of state. According to CDC guidelines, any Illinois
resident diagnosed with a tickborne disease is counted in the state’s case count, even
though he/she may have reported tick exposures in another state. Case counts by year
for 2001 through 2006 for four of these infections that occur regularly in Illinois are
shown in Figure 102.
Number of ehrlichiosis and Rocky mountain spotted fever cases increased in
2006 as compared to previous years.
150
100
50
0
Figure 102. Tickborne Disease Cases in Illinois, 2001-2006
127
87
71
47
32 14
14 5 12
12
12 5 6
11 1 7
7
5 1 9
2001
2002
2003
2004
2005
Year
Lyme
RMSF
186
Tularem ia
Ehrlichiosis
110
26
1
2006
32
Table 15. Tickborne Diseases Reported in Illinois Residents
Disease
Organism
Tick vectors
Symptoms
Where found
Rocky Mountain
spotted fever
Rickettsia
rickettsii
Dermacentor
variabilis
(American dog
tick),
D. andersoni
(Rocky Mountain
wood tick)
fever, headache,
rash
throughout the
United States but
most common in
Southeast; entire
state of Illinois
Tularemia
Francisella
tularensis
Amblyomma
americanum
(lone star tick),
D. variabilis,
D. andersoni
ulcer at entry site,
enlarged lymph
node
throughout North
America; primarily
central and
southern Illinois
Lyme disease
Borrelia
burgdorferi
Ixodes scapularis
(deer tick)
fatigue, chills,
fever, erythema
migrans, enlarged
lymph nodes
primarily on the
West Coast, in
northeastern and
north central
United States;
primarily northern
Illinois
Human monocytic
ehrlichiosis
Ehrlichia
chaffeensis
A. americanum
fever, headache,
myalgia, vomiting
most common in
the southern
states; more
common in
southern Illinois
Human
granulocytic
ehrlichiosis
Anaplasma
phagocytophilum
I. scapularis
fever, headache,
myalgia, vomiting
most common in
upper Midwest
and Northeast; in
Illinois, unknown
distribution
* Although suspected to be present in Illinois, no diagnostic test is available yet.
187
Toxic Shock Syndrome (TSS) Due to Staphylococcus aureus
Background
Toxic shock syndrome is classified by clinical and laboratory evidence of fever,
rash, desquamation, hypotension and multiple organ failure caused by toxins produced
by Staphylococcus aureus. MRSA strains have caused TSS in other countries. Most
cases have been associated with strains of Staphylococcus aureus that produce a
special toxin.
In 2006, 101 cases were reported to CDC nationally.
Case definition
The five clinical findings used to establish whether a case meets the case
definition for staphylococcal TSS are 1)
Fever - temperature greater than 102 F
2)
Rash
3)
Desquamation
4)
Hypotension
5)
Multisystem involvement (three or more of the following)
a.
Gastrointestinal - vomiting or diarrhea
b.
Muscular - myalgia or creatine phosphokinase (at least twice upper limit of
normal)
c.
Mucous membrane - vaginal, oropharyngeal or conjunctival hyperemia
d.
Renal - blood urea nitrogen or creatinine at least twice the upper limit of
normal or urinary sediment with pyuria in the absence of urinary tract
infection
e.
Hepatic - total bilirubin, alanine aminotransferase (ALT) or aspartate
aminotransferase (AST) at least twice the upper limit of normal for the lab
f.
Hematologic - platelets less than 100,000/mm3
g.
CNS - disorientation or alterations in consciousness without focal
neurologic signs when fever and hypotension are absent.
In addition, there should be negative results on the following tests (if done)
a.
Blood, throat or CSF cultures (blood cultures can be positive for S.
aureus)
b.
Rise in titer to Rocky Mountain spotted fever, leptospirosis or measles
The CDC case definition for a probable case is one with any four of the five
clinical findings above. A confirmed case is one with all five of the clinical findings,
including desquamation, unless the patient dies before desquamation can occur.
Descriptive epidemiology
•
•
•
•
Number of cases reported in Illinois in 2006 - Two cases were reported (five-year
median = five cases). One was confirmed, and one was probable.
Age - Ages were 33 and 36.
Gender - Both cases were female.
Seasonality – Cases had onsets in March.
188
•
•
•
•
•
•
Race/ethnicity – One case was white; the other did not report race. One case with
information available was not Hispanic.
Geographic distribution - Cases resided in Cook and Kane counties.
Treatment - Both patients were hospitalized.
Outcome – One case was fatal.
Reporting – One case was reported by a hospital; the other by a laboratory.
Past cases – Toxic shock syndrome cases due to S. aureus reported per year in
the state previously were 1998 (seven), 1999 (five), 2000 (three), 2001 (four), 2002
(five), 2003 (six), 2004 (six) and 2005 (five).
Summary
Two cases of staphylococcal toxic shock were reported in 2006 and were
considered to be associated with menstruation.
189
Tuberculosis
Background
The Mycobacterium tuberculosis complex includes M. tuberculosis, M. africanum,
M. bovis and M. microti. Tubercle bacilli are transmitted by inhalation of airborne droplet
nuclei produced by persons with tuberculosis (TB) disease. Prolonged close contact
with cases may lead to latent TB infection (LTBI). Tuberculin skin sensitivity often
indicates LTBI (as noted by a positive skin test), which usually appears four to 12 weeks
after infection. LTBI is different from TB disease and is defined as a condition in which
TB bacteria are alive but inactive in the body. People with latent TB infection have no
symptoms and cannot spread TB to others. They usually have a positive skin test
reaction and may develop TB disease later in life if they do not receive treatment for
latent TB infection.
Approximately 90 to 95 percent of newly infected individuals have LTBI where
early lung lesions heal and leave no residual changes except small calcifications in the
pulmonary or tracheobronchial lymph nodes. In those patients whose infection
progresses to disease, early symptoms may include fatigue, fever, night sweats and
weight loss. In advanced disease, symptoms such as cough, chest pain, coughing up of
blood, and hoarseness may occur.
Several issues, such as patients’ immune status and immigration from areas
where TB is common, impact the incidence of TB in Illinois. In 2006, CDC
recommended routine HIV screening for all TB patients, unless the patient declines to
accept testing. The AIDS epidemic had a profound effect on the number of TB cases in
Illinois in the past. TB is a major opportunistic infection in HIV-infected persons. HIV
contributes to TB because immune suppression increases the likelihood of rapid
progression from TB infection to TB disease. In Illinois, the percentage of TB cases
diagnosed in foreign-born individuals is increasing. CDC recommends that all
immigrants, refugees, foreign-born students and their families, and others
accompanying them into the country be tuberculin-test screened and medically treated
when appropriate.
Both suspected and confirmed cases of TB are reportable in Illinois. The sooner
cases are reported to the local TB control authority, the sooner their personnel can
begin investigations which may interrupt transmission of TB in the community.
Extensively drug resistant (XDR) TB is TB which is resistant to isoniazid and rifampin
and resistance to any fluoroquinolone, and resistance to at least one second-line
injectable drug (amikacin, capromycin or kanamycin). From 1993 to 2006, 49 TB cases
in the United States were classified as XDR-TB including one case from Illinois.
The recommended length of drug therapy for most types of TB is six to nine
months. Treatment of multi-drug resistant TB requires administration of four to six drugs
for 18 to 24 months. Patients with both TB and HIV are more likely to die during anti-TB
treatment than patients not infected with HIV.
During 2006, a total of 13,779 cases (4.6 per 100,000) were reported to CDC.
Forty-three percent were among United States-born persons (2.3 per 100,000
population). In 2006, the overall TB case rate was 9.5 times higher in foreign-born
persons than among United States-born persons.The rate was higher than the 2010
national objective of less than one case per 1,000,000 population. The highest rates
190
were in African Americans and Asians.
Case definition
A confirmed case of tuberculosis in Illinois is a case that is either laboratory
confirmed or is a case that meets the clinical case definition criteria:
1)
A positive tuberculin skin test
2)
Other signs and symptoms compatible with tuberculosis, such as an
abnormal, unstable chest radiograph, or clinical evidence of current
disease
3)
Treatment with two or more anti-tuberculosis medications
4)
Completed diagnostic evaluation
Laboratory criteria for diagnosis are isolation of M. tuberculosis from a clinical
specimen, demonstration of M. tuberculosis from a clinical specimen by DNA probe or
mycolic acid pattern on high-pressure liquid chromatography, or demonstration of acidfast bacilli in a clinical specimen when a culture has not been or cannot be obtained.
Descriptive epidemiology
•
•
•
•
•
•
•
•
Number of cases reported in Illinois in 2006 – 569 (4.4 per 100,000 population).
(Figure 103).
Age - The highest incidence of TB occurred in the 45 to 64 and 65 and older age
groups (Table 16).
Gender – Fifty-nine percent were male.
Race/ethnicity – Thirty-five percent were African American (non-Hispanic), 16
percent white (non-Hispanic), 34 percent Hispanic and 24 percent were Asian or
Pacific Islander.
► The number and percent of foreign-born TB cases increased in 2006 (N =
305, or 54 percent) as compared to 2005 (N = 268 or 45 percent) (Figure
104). Cases were born in 52 foreign countries. The largest number of cases
were born in Mexico (29 percent), followed by India (18 percent) and the
Philippines (13 percent). Persons born in China, Viet Nam and South Korea
(11 percent combined) also were represented among foreign-born cases.
Risk factors – Risk factors included homeless in past 12 months (5 percent), being
an inmate in a correctional facility (4 percent), injection drug use (2 percent) and
residing in a long-term care facility (2 percent).
Diagnosis – Seventy-seven percent of cases were culture confirmed, 12 percent
were provider diagnosed, 10 percent were clinically diagnosed and 0.9 percent were
smear positive.
Drug resistance – One MDR and no XDR-TB cases were reported.
Clinical syndrome – Sixty-five percent of cases were pulmonary, 27 percent were
extrapulmonary and 7 percent were both. Between 2002 and 2006, there were 78
percent of 1,036 TB cases aged 25 to 44 that had a valid HIV status. Twelve percent
were HIV positive.
191
Summary
In 2006, 569 cases of TB were reported in Illinois with an incidence rate of 4.4
per 100,000, which is very similar to the national incidence rate. Fifty-four percent of
these cases were among persons born outside of the United States. An increasing
percentage of foreign-born cases are being seen in Illinois, with India, Mexico and the
Philippines being the most common countries of origin. This is the first year in Illinois
that foreign-born cases outnumbered U.S. born cases. Public health attention must
continue to focus on high-risk groups, especially those born outside of this country.
Illinois is one of seven states reporting more than 500 cases and is fifth in the nation in
the number of cases reported.
Suggested readings
Pratt, R., et al. Trends in tuberculosis in tuberculosis incidence-United States,
2006.MMWR 2007;56(11):245-250.
Shah, N.S., et al. Extensively drug-resistant tuberculosis-United States,19932006. MMWR 2007; 56(11):250-53.
Table 16. Age Distribution of Tuberculosis Cases in Illinois, 2006
Age
Incidence *
< 5 years
3.2
5 – 14
0.8
15 – 24
2.9
25-44
4.7
45-64
6.0
65+
7.6
All
4.4
U.S.
4.6
* Incidence per 100,000 based on 2000 population.
Source: Illinois Department of Public Health
192
Number of cases
Figure 103. Tuberculosis Cases in Illinois, 2001-2006
500
400
300
200
100
0
448
259
415
265
407
339
230
273
328
268
305
264
Foreign born
US born
2001
2002
2003
2004
2005
2006
Year
Figure 104 . Country of Origin for Foreign-born TB Cases, Illinois, 2006
India
Other
29%
India
18%
Mexico
China, Vietnam,
South Korea
Philippines
Other
Philippines
13%
China, Vietnam,
193
Mexico
29%
Tularemia
Background
Tularemia is caused by Francisella tularensis and is a zoonotic disease that
infects vertebrates especially rabbits and rodents. Tularemia can be classified into six
primary syndromes: ulceroglandular (the most common form), glandular, typhoidal,
oculoglandular, oropharyngeal, and pneumonic. The case fatality rate can be 30 percent
to 60 percent if untreated and typhoidal. Tularemia can be divided into four subspecies.
Human disease is mainly associated with F. tularensis subsp tularensis, found only in
North America, and the moderately virulent F. tularensis subsp. Holartica, which is
endemic throughout the northern hemisphere. F. tularensis subspecies tularensis can be
separated into two subpopulations in the United States, A.I. and A.II. A.1. occurs
primarily in the central United States and A.II. occurs primarily in the western United
States. Tularemia can affect many wildlife species, including prairie dogs, squirrels, and
cats in addition to humans. Both ticks and biting flies can serve as vectors in the United
States.
The most common modes of transmission are tick bites and handling infected
animals. The disease also can spread through ingestion of contaminated water or food,
inhalation, and insect bites.
Tularemia has two peaks in occurrence; a peak in the summer reflects
transmission from ticks and a peak in winter reflects transmission from animal contact,
especially rabbits, often during hunting or trapping seasons. The most important
epizootic hosts for tularemia in the United States include rodents and lagomorphs.
Tularemia has been associated with die-offs in exotic pet animals, such as prairie dogs.
From 1990 to 2000, tularemia was primarily reported from Arkansas, Missouri, Oklahoma
and South Dakota.
The most common tick vectors in the United States are the American dog tick
(Dermacentor variabilis), the Lone Star tick (Amblyomma americanum) and the Rocky
Mountain wood tick (D. andersoni).
The incubation period is three to five days. Clinical signs in people include fever,
chills, malaise, cough, myalgias, vomiting and fatigue followed by the development of
one of six clinical syndromes. Isolation of F. tularensis requires biosafety level 3 facilities.
Tularemia is considered a possible bioterrorism agent. Vaccination is recommended only
for limited numbers of persons in high-risk occupations.
In 2006, 95 cases were reported to CDC from 26 states.
Prevention methods include wearing gloves when handling dead animals,
especially rabbits and rodents; avoiding bites of ticks, flies and mosquitoes by using
insect repellents, cooking game meat thoroughly, and avoiding drinking of untreated
water.
Case definition
The CDC case definition for a confirmed case of tularemia is a clinically
compatible case with either isolation of F. tularensis from a clinical specimen or a fourfold or greater rise in serum antibody titer to F. tularensis antigen. A probable case is a
clinically compatible case with either detection of F. tularensis in a clinical specimen by
fluorescent antibody or an elevated serum antibody titer to F. tularensis antigen in a
patient with no history of vaccination.
194
Descriptive epidemiology
• Number of cases reported in Illinois in 2006 – One probable case was reported.
• Age - The case’s age was 6.
• Gender – This case was female.
• Seasonal variation – The onset of illness was in August.
• Geographic distribution – The exposure site for the case was Washington County.
• Symptoms/diagnosis/treatment – The case was not hospitalized. A single serologic
test was positive.
• Exposures – The patient reported a tick bite while on his own property.
• Past incidence - The numbers of cases in Illinois by year are as follows: 1991 (five),
1992 (two), 1993 (three), 1994 (three), 1995 (four), 1996 (four), 1997 (five), 1998
(five), 1999 (two), 2000 (four), 2001 (14), 2002 (five), 2003 (one), 2004 (five) and
2005 (one).
Summary
The number of cases of tularemia was the same as in 2005. Only one case was
reported.
195
Typhoid Fever
Background
Typhoid fever is a systemic infection caused by infection with Salmonella enterica
serotype Typhi. The incubation period is from three days to three months with a usual
range of one to three weeks. Transmission of typhoid fever is usually by ingestion of food
or water contaminated by fecal or urinary carriers of S. enterica serotype Typhi. Types of
products implicated in some countries include shellfish, raw fruits, vegetables and
contaminated milk or milk products. Unlike other types of Salmonella, S. enterica ser.
Typhi is not found in animal reservoirs; humans are the only reservoirs. In developed
countries like the United States, most cases are sporadic after travel to endemic areas.
The infectious dose ranges from 1,000 to 1 million organisms. Constipation is more
common than diarrhea in adults. The onset of bacteremia with typhoid fever results in
fever, headache, abdominal discomfort, dry cough and myalgia. Other findings may
include bradycardia, rash and splenomegaly. Complications may include gastrointestinal
bleeding, intestinal perforation, and typhoid encephalopathy. Relapse may occur in 5
percent to 10 percent of patients, usually two to three weeks after resolution of fever. As
many as 10 percent of untreated patients will shed organisms in the feces for up to three
months. One percent to four percent may develop long-term carriage of the organism for
as long as one year. Most carriers are asymptomatic. Chronic carriage is more common
in women, the elderly and in patients with cholelithiasis.
Typhoid fever is typically diagnosed with blood cultures. Bone marrow cultures
also can be used. For travelers to developing countries, water should be boiled or bottled
and food should be thoroughly cooked to avoid acquiring typhoid fever. Vaccination is
recommended for persons traveling to areas where typhoid is endemic.
In 2006, 353 typhoid fever cases were reported in the United States.
Approximately three-quarters of all cases occur among persons who report international
travel during the prior month. Persons visiting South Asia are at particular risk.
Case definition
A confirmed case is a clinically compatible illness with isolation of S. enterica ser.
Typhi from blood, stool or other clinical specimen. A probable case is defined as a
clinically compatible illness that is epidemiologically linked to a confirmed case in an
outbreak.
Descriptive epidemiology
•
•
•
•
•
Number of cases reported in Illinois in 2006 – 18 (five-year median = 17) (see
Figure 105). All were confirmed cases.
Sex – Eleven (61 percent) were male.
Age - Cases ranged in age from 11 months to 73 years of age (median = 17
years).
Race/ethnicity – Eleven of 18 (61 percent) were Asian; four (22 percent) were
white, none were African American, and three (17 percent) were other races.
Three of 16 cases (19 percent) were Hispanic.
Seasonal variation – Cases were reported from January through November.
196
•
•
•
•
•
•
Geographic distribution – Sixty-one percent of the cases were Cook County
residents.
Reporting – Thirty-nine percent were reported by infection control professionals,
and 61 percent were reported by laboratories.
Diagnosis – The specimen testing positive was blood (12), stool and blood (one),
stool (three) and unknown (two).
Employment - No cases were reported to be in sensitive occupations.
Treatment/outcomes
o Twelve of 18 cases (67 percent) were hospitalized. No deaths were
reported.
Risk factors - Travel destinations for imported cases included India (eight),
Pakistan (five), Mexico (two), El Salvador (one) and Philippines (one). One person
reported no travel, and no source of infection could be identified.
Summary
There were 18 typhoid fever cases reported in Illinois in 2006. Most cases were
acquired outside the United States. India and Pakistan were the most common travel
destinations for those cases who reported travel outside the United States.
Number of cases
Figure 105. Typhoid Fever Cases in Illinois, 2001-2006
25
20
15
10
5
0
23
18
2001
17
2002
18
18
16
2003
2004
Year
197
2005
2006
Varicella (chickenpox)
Background
Chickenpox (varicella) is a highly infectious disease caused by varicella-zoster
virus (VZV) and is characterized by sudden onset of slight fever and a rash. Lesions
present with successive crops and several stages of maturity present at the same time.
Serious complications of varicella may occur and can include pneumonia, secondary
bacterial infections, hemorrhagic complications, and encephalitis. Herpes zoster
(shingles) is a local manifestation of reactivation of latent varicella in dorsal root ganglia.
Severe pain and paresthesia may accompany this manifestation. Fifteen percent to 30
percent of the population experience Herpes zoster (HZ) during their lifetime.
Postherpetic neuralgia can occur with debilitating pain weeks to months after resolution
of HZ. Risk factors for HZ include initial infection with varicella in utero or when less
than 18 months of age. Intrauterine VZV infection can result in congenital varicella
syndrome, neonatal varicella or HZ during infancy or early childhood.
The incubation period is 14 to 16 days after exposure to rash (range 10-21 days).
A person is communicable for one to two days before rash onset and remains infectious
until the rash is crusted over (usually four to seven days after rash onset). The disease
is transmitted through direct contact between persons, droplet or airborne spread of
vesicle fluid or respiratory tract secretions or indirectly through fomites. Secondary
attack rates in households can be 90 percent.
Varicella or chickenpox is a highly infectious vaccine preventable disease.
Cases of varicella were reported from 33 states to CDC in 2006. In 2006, the
Advisory Committee on Immunization Practices (ACIP) updated its recommendations to
include a second dose of varicella vaccine for children and catch-up vaccination for
persons with no evidence of immunity. Approximately one in five vaccinated children
may develop break through varicella disease if exposed to the virus. Illness is generally
less severe than in unvaccinated persons. One dose of varicella vaccine is 80 percent
to 85 percent effective against varicella disease.
Two live attenuated vaccines are available for varicella zoster virus in the United
States. One was licensed in 1995 and the other in 2005. Recommendations for varicella
prevention are to:
1)
Implement a two-dose varicella vaccination program for children (the first
dose at 12-15 months and the second at 4-6 years)
2)
Provide a second catch-up varicella vaccination for children, adolescents
and adults who had previously received one dose
3)
Encourage routine vaccination of all healthy persons aged greater than 13
years without evidence of immunity
4)
Conduct prenatal assessment and postpartum vaccination
5)
Expanding use of varicella vaccination for HIV-infected children with agespecific CD4 and T lymphocyte percentages of 15 percent to 24
percent and adolescents and adults with CD4 and T lymphocyte
counts greater than 200 cells/ul
6)
Establish middle school, high school and college entry,vaccination
requirements
197
Illinois implemented school entry requirements for varicella vaccination in July
2002. It is required for those entering kindergarten in 2002 and for those entering first
grade in 2003. Vaccination also is required in all preschools that are run by the school
district and which have children aged 2 or older. In 2003, the Department also required
reporting of adult chickenpox (in those older than 20 years of age) within 24 hours from
the medical practice act. Permanent rules were enacted for reporting as of March 2008.
This reporting was implemented because a case of smallpox in an adult might be
misidentified as a case of chickenpox.
The national immunization survey of Illinois children aged 19-35 months of age
shows that 85 percent of children had received one or more doses of varicella vaccine
at or after the child’s first birthday as compared to 89 percent nationally.
Case definition
Physician diagnosed cases are reported to the Department with a weekly
summary from local health jurisdictions. Only individual cases of adult varicella are
reported.
Descriptive epidemiology
•
•
•
•
•
•
Number of cases – For aggregate reporting, 1,915 cases were reported (five-year
median = 6316). In adults, 134 cases were reported. Of the adult cases, 84 were
classified as confirmed and 50 were probable.
Sex – Of the adult cases, 70 were female and 64 male.
Age – Adult cases ranged in age from 21 to 93 (mean = 37).
Clinical – Twenty-five adult cases were hospitalized and none were fatal.
Seasonal – Adult cases occurred in all months of the year with a slight increase in
April and May.
Geographic location – Cases were residents of 31 counties. Counties reporting the
most cases were Cook (46), Kane (14) and Will (12).
Summary
Varicella (chickenpox) is reportable in aggregate in Illinois, and almost 2,000
cases were reported in 2006. The goal for vaccination levels is 90 percent by 2010.
Suggested readings
Chaves, S.S., et. al. Varicella disease among vaccinated persons: Clinical and
epidemiological characteristics, 1997-2005. JID 2008;197:S127-31.
Lopez, A.S., et. al. Status of school entry requirements for varicella vaccination
and vaccination coverage 11 years after implementation of the varicella vaccination
program. JID 2008; 197:576-581.
Marin, M. et. al. Prevention of varicella. Recommendations of the Advisory
Committee on Immunization Practices (ACIP): MMWR 2007;56(RR-4):1-40.
Wooten, K.G. et al. National, state and local area vaccination coverage among
children aged 19-35 months-United States, 2006. MMWR 2007;56(34): 880-5.
198
Vibrio Non-cholera
Background
Vibrio parahaemolyticus infection causes acute diarrhea, vomiting and fever for
one to three days. The incubation period usually occurs within 24 hours after eating
contaminated food. Foods most often associated with this illness include raw or
undercooked shellfish or other cooked foods that have been cross contaminated with
raw shellfish. Vibrio spp multiply rapidly and can increase quickly if seafood is not
rapidly refrigerated after harvest and kept at proper temperatures. Diagnosis is by
culturing stool specimens in persons with shellfish consumption history and symptoms.
The selective media, thiosulfate-citrate-bile salts-sucrose (TCBS), can be used to
isolate the organism. It is estimated that 20 cases actually occur for every laboratory
confirmed case reported to CDC. From 1997 through 2006, there were 4,754 Vibrio
infections reported to CDC. One-quarter of cases were not foodborne. Most of these
non-foodborne Vibrio infections were due to V. vulnificus, mainly in residents of the Gulf
Coast states. In preliminary CDC FoodNet data the incidence was 0.34 cases per
100,000. Among 147 Vibrio isolates identified to species, 94 (64 percent) were V.
parahaemolyticus and 18 (12 percent) were V. vulnificus. In 2007, all Vibrio became
nationally notifiable.
A cluster of V. parahaemolyticus occurred in three states in 2006 due to
consumption of raw shellfish. The implicated oysters were from Washington.
Prevention of Vibrio infections can include cooking shellfish thoroughly cooked to
kill pathogens like V. parahaemolyticus.
Case definition
A confirmed case is a clinically compatible case from which Vibrio spp. has been
isolated from a clinical specimen. A probable case is a clinically compatible case that is
epidemiologically linked to a confirmed case; or a clinically compatible case who
consumed epidemiologically incriminated food (usually seafood) from which 1 million or
more organisms per gram have been identified.
Descriptive Epidemiology - V. parahaemolyticus
• Cases – Seven cases were reported in 2006. All were confirmed.
• Seasonal – Cases were reported from June to September.
• Race – Four of four cases with race identified were white; none were reported as
Hispanic.
• Sex – Eighty-six percent of cases were male.
• Age – Cases ranged from 30 to 55 years of age (mean = 40).
• Risk factors – Three cases reported eating raw oysters, and one reported eating
raw fish. Three had an unknown source.
• Outcome – One of five cases for which hospitalization data was available
hospitalized. No cases were reported to be fatal.
• Reporter – Four were reported by laboratories and three were reported by
hospitals.
199
Descriptive epidemiology - other Vibrio species
• Cases - Eight cases were reported in 2006. All were confirmed.
• Seasonal – Cases were reported from March to December.
• Race – Six cases were white; none were Hispanic.
• Sex – Fifty percent of the cases were male.
• Outcome – Hospitalization status was known for six cases and three was
hospitalized. No deaths were reported.
• Reporter – Five cases were reported by laboratories and three by hospitals.
• Age – Cases ranged in age from 1 year to 88 years of age (mean = 43).
• Geographic – Six counties reported cases including Cook (two cases), and
DuPage (two cases). There was one case each in Kane, Grundy, Kankakee
and Tazewell counties.
• Species – Vibrio species identified in cases included Vibrio fluvialis (two),
Vibrio alginolyticus (one), Vibrio cholerae non 01 (three), Vibrio mimicus (one)
and Vibrio, unknown species (one).
• Individual descriptions of cases
o A 29-year-old male from Grundy County who had previously received
an organ transplant was diagnosed in August with V. cholerae non-O1.
He had not traveled outside of Illinois. His seafood consumption history
was unknown.
o A 60-year-old female undergoing chemotherapy from Kankakee
County was diagnosed with V. cholerae non-O1 in March. She may
have consumed cooked frozen shrimp.
o A 78-year-old female from Cook county was diagnosed with Vibrio,
unknown type in July. No history was available.
o A 1-year-old from Dupage county was diagnosed with V. fluvialis in
December. Risk factors were not available.
o In March, a 37-year-old female from Cook county was diagnosed with
V. mimicus. Risk factors were unknown.
o A Tazewell county resident was diagnosed with V. fluvialis. She was
an 88-year-old female and risk factors were unknown.
o A 4-year-old from Dupage county was diagnosed with V. alginolyticus
in August. Risk factors were not known.
o A 44-year-old from Kane County was diagnosed with V. cholera non
O1 in March. The patient had traveled to the Dominican Republic and
had contact with sea water and may have eaten seafood.
Suggested readings
Dechet, A.M., et. al. Nonfoodborne Vibrio infections: An important cause of
morbidity and mortality in the United States, 1997-2006. Clin Inf Dis 2008; 46:970-6.
200
201
Yersiniosis
Background
Yersiniosis, an infrequently reported cause of diarrhea in the United States, is
caused by Yersinia enterocolitica or Y. pseudotuberculosis. Transmission is by the
fecal-oral route, through consumption of contaminated food or water or by contact with
infected people or animals. The incubation period is three to seven days. Fecal
shedding occurs for as long as symptoms are present, usually two to three weeks.
Manifestations of the disease include an acute febrile diarrhea and abdominal pain.
Symptoms can mimic appendicitis. Bloody diarrhea is seen in 10 percent to 30 percent
of children with Y. enterocolitica. Animals are the principal reservoir for Yersinia, with
the pig the primary reservoir of Y. enterocolitica; rodents are the main reservoirs for Y.
pseudotuberculosis. Most pathogenic strains of Y. enterocolitica have been isolated
from raw pork or pork products. Chitterling consumption or contact with someone
preparing chitterlings is a common exposure history for those with yersiniosis. Yersinia
is cold-tolerant and can replicate under refrigeration.
Of the 10 diseases (those caused by Campylobacter, Cryptosporidium,
Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella,
Vibrio and Yersinia enterocolitica) under active surveillance in the federal FoodNet sites,
Yersinia comprised 158 of 17,252 (0.9 percent) of the reported infections in data from
2006. The incidence rate per 100,000 for yersiniosis in 2006 data was 0.35 (range from
0.2 to 0.5) at the nine FoodNet sites with preliminary data.
Case definition
The case definition for a confirmed case in Illinois is a positive culture for
Yersinia. A probable case is a case linked by epidemiology to a confirmed case but not
culture positive.
Descriptive epidemiology
• Number of reported cases in Illinois in 2006 - 31 (five-year median = 25) (see Figure
106). The incidence rate per 100,000 was 0.25. All were confirmed cases.
• Age – Nine cases (29 percent) occurred in those younger than 1 year of age. (Figure
107).
• Gender – Fifty-three percent of cases were female.
• Race/ethnicity - Thirty-five percent were African American and 54 percent were
white. Twenty-two percent were Hispanic.
• Seasonality – Figure 108 shows the case onsets by month. Higher numbers of
cases were reported in November and December.
• Geographic location – Forty-four percent of cases were residents of Cook County,
followed by 16 percent in St. Clair County.
• Clinical history – Five of 28 (18 percent) had diarrhea; 14 of 28 (50 percent) had
vomiting, and 17 of 28 (61 percent) had fever.
• Outcome – For 29 cases with complete case information, 17 cases were
hospitalized and no cases were reported to be fatal.
• Risk factors – History of chitterling consumption was obtained for 25 cases and five
cases had exposure to chitterlings. Three of the cases with chitterling exposure were
202
•
younger than 2 years of age.
Reporting – The most important source of reporting was infection control
professionals (20 cases), followed by laboratories (eight cases).
Summary
The yersiniosis incidence rate of 0.25 per 100,000 for 2006 in Illinois was similar
to that found in the CDC’s FoodNet sites. Twenty-nine percent of cases in 2006 with
age information occurred in children younger than a year old.
Number of cases
Figure 106. Yersiniosis Cases in Illinois, 2001-2006
40
38
25
30
31
28
25
22
20
10
0
2001
2002
2003
2004
2005
2006
Year
Number of cases
Figure 107. Age Distribution of Yersiniosis Cases in Illinois, 2006
10
8
6
4
2
0
<1 yr
1-4 yr
5- 9 yr
1 0-19 yr
20-29 yr
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Age Group
Number of cases
Figure 108. Yersinia Cases in Illinois by Month, 2006
10
8
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
203
Aug
Sep
Oct
Nov
Dec
Non-foodborne, Non-waterborne Outbreaks, 2006
Case definition
A non-foodborne, non-waterborne (NFNW) outbreak is an incident in which two
or more persons (usually residing in separate households) experience the onset of a
similar, acute illness following a common exposure (other than ingestion of common
food or drink or exposure to recreational water).
For NFNW outbreaks, the number ill reflects those who meet a clinical case
definition. For outbreaks where the etiologic agent was suspected and not confirmed,
and the clinical syndrome matched the suspect etiologic agent but no laboratory
confirmation was obtained, the suspect cause is ascribed to this etiologic agent.
The Department receives reports of potential NFNW outbreaks from many
sources. Outbreak investigations, which are conducted by local health departments,
may not result in an Illinois NFNW outbreak designation and will not be counted in the
state totals.
Descriptive epidemiology
The number of NFNW outbreaks reported and counted during 2006 was 121. Of
the 121 NFNW outbreaks, the etiology was confirmed in 78 outbreaks, suspected in 41
outbreaks and unknown in two outbreaks. The mode of transmission was person to
person (115), other (one), respiratory (one) and unknown (four).
In the year 2006, a total of 4,995 people were reported to have become ill as the
result of these outbreaks. The mean number of cases ill was 41 per NFNW outbreak.
There were 139 persons hospitalized and three fatalities as a result of the NFNW
outbreaks. A map of the NFNW outbreaks reported by county during 2006 is available in
Figure 109.
The 121 reported NFNW outbreaks occurred in the following months: January,
three (2.5 percent); February, eight (6.7 percent); March, 14 (11.5 percent); April, 11
(9.0 percent); May, eight (6.7 percent); June, four (3.3 percent); July, three (2.5
percent); August, seven (5.8 percent); September, four (3.3 percent); October, seven
(5.8 percent); November, 20 (16.5 percent); and December, 32 (26.4 percent) (Figure
110). In the 121 NFNW outbreaks reported, the etiologic agent was determined to be
due to bacterial agents (infection or intoxication), either suspect or confirmed, in 11 (9
percent) (Tables 17 and 18). The bacterial pathogens were as follows: Shigella sonnei
(five), Streptococcus, Group A (two), methicillin resistant S. aureus (one outbreak), S.
marcescens (one), A. xylosoxidans (one) and C. difficile (one). One outbreak each was
caused by histoplasmosis and cryptosporidiosis. Viral agents included norovirus (106
outbreaks). Sixty-six (62 percent) of these viral outbreaks were laboratory confirmed
and 40 (38 percent) were suspect norovirus, not laboratory confirmed. Suspect
norovirus outbreaks were classified largely based on symptoms, incubation and
duration in the people who were affected.
Although thorough investigations were conducted, there was inconclusive
evidence to classify either suspect or confirm etiologic agents in two (1.6 percent) of the
NFNW outbreaks and they were thus classified as etiology unknown.
The site of the outbreak in NFNW outbreaks were: LTC (66 outbreaks), hospital
(24), day care (nine), other elder facilities (eight), schools (six), residential facility (two)
204
and one each for college, choir camp, work site, neighborhood, convention center at
hotel and house construction site. Table 19 provides an individual line listing of all 2006
NFNW outbreaks.
Figure 110. Number of Non-foodborne Non-waterborne
Outbreaks by Month of First Onset, Illinois, 2006
40
Number of 30
outbreaks 20
reported 10
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Summary
In 2006, Illinois recorded 121 NFNW outbreaks. The most common site of an
outbreak was long-term care facilities. Almost 5,000 persons became ill, 139 were
hospitalized and three fatalities were a consequence of these outbreaks. Outbreaks
were reported from 38 counties. Viral agents were the main cause of NFNW outbreaks.
205
Table 17. Non-foodborne Non-waterborne Outbreaks, Cases, and Deaths by Etiology in Illinois, 2006
Outbreaks
Cases
#
Etiology
Count
%
Count
%
Bacterial
S. marcescens
1
0.8
4
0.08
C. difficile
1
0.8
3
0.06
MRSA
1
0.8
4
0.08
A. xylosoxidans
1
0.8
10
0.2
Shigella
5
4
88
2
Streptococcus, Group A
2
2
5
0.08
Total Bacterial*
11
114
Viral
Norovirus
106
100
4791
96
Total Viral
106
4791
Parasites
0.34
Cryptosporidiosis
1
100
17
Total Parasites
1
17
Fungi
Histoplasmosis
1
Total Fungal
1
UNKNOWN
2
0.8
2
0.04
2
2
71
206
Deaths
Count
0
0
0
0
0
3
3
0
0
0
0
0
100
0
0
--
0
0
--
0
0
1.4
%
0
Table 18. Non-foodborne Non-waterborne Outbreak Pathogens by Testing Status in Illinois, 2006
Confirmed
Suspected
Etiology
Count
%
Count
%
Bacterial
S. marcescens
1
1.2
0
-
C. difficile
1
1.2
0
-
MRSA
1
1.2
0
-
Alcaligenes xylosoxidans
1
1.2
0
-
Shigella
5
6
0
-
Streptococcus, Group A
2.6
0
0
-
Total Bacterial
2
11
Cryptosporidiosis
0
0
1
2
Total Parasitic
0
Norovirus
66
Total Viral
66
Histoplasmosis
1
Total Fungal
1
Unknown
Count
%
Parasites
1
Viral
85
40
98
40
Fungi
1.2
0
-
0
Unknown
3
207
Specific Types of NFNW Outbreaks
Bacterial Outbreaks
C. difficile
Background
C. difficile is a spore forming bacteria. This organism can produce two toxins (A
and B). The organism can cause diarrhea and pseudomembranous colitis. Many cases
have been on antimicrobials prior to onset of illness. Asymptomatic carriers are
possible. The symptoms can recur after treatment. The mortality ranges from 1 percent
to 2.5 percent. The incidence and severity has been increasing in the United States.
Community-associated C. difficile also is being observed. Approximately one-third of
cases had no prior antimicrobial use.
Case definition
A confirmed C. difficile outbreak requires at least two confirmed cases with an
epidemiologic link.
Descriptive epidemiology
• Number of outbreaks in Illinois in 2006 – One outbreak was reported.
• Individual Outbreak Descriptions
o A cluster of three cases of C. difficile were reported in residents of the first
floor of a long-term care facility in Cook County. Onsets ranged from
December 6 through 11. Diarrhea was present in all three residents. No
hospitalizations or fatalities occurred.
C. difficile
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
December
Counties of outbreaks
Cook
Confirmed
1
3
-0
0
1
1
Shigella
Background
The Shigella organism can cause person-to-person outbreaks. Symptoms
include fever and diarrhea.
Case definition
The case definition for an outbreak of Shigella is identification of the same
serotype of the bacteria in two or more ill persons with a common epidemiologic link.
208
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 – Five confirmed outbreaks were
reported. All outbreaks were caused by S. sonnei and all occurred in day care
centers. Eighty-eight persons became ill as a result of the five outbreaks and two
were hospitalized. Four outbreaks took place in July and August. These five
outbreaks were reported from four counties.
• Individual outbreak descriptions
o A cluster of two cases of S. sonnei occurred in a day care in Winnebago
County. A secondary case occurred in a family member of one of the day
care attendees. Three persons were culture positive. Onsets ranged from July
12 through July 21.
o One day care provider, four day care attendees and one mother of a home
day care attendee developed diarrheal illness in Chicago. Five of the six
tested positive for S. sonnei. Onsets ranged from July 22 through August 6.
Ages of the children were 1 year, 2 year, and two five-year-olds. Three cases
were female and three were male.
o Three attendees of a day care in Champaign developed Shigella sonnei.
Onsets of illness ranged from August 23 through August 25. No children were
hospitalized. Cases ranged in age from 3 to 5 years of age. There were
approximately 65 attendees.
o From August 7 through September 7, there were 74 persons with
gastrointestinal illness at a day care in Morgan County. Eight were staff and
66 were attendees. Sixteen were confirmed Shigella sonnei cases; the rest
were probable. Of the confirmed cases, 80 percent had diarrhea, 47 percent
reported fever and 27 percent reported vomiting. One person was
hospitalized.
o Two cases of Shigella sonnei occurred in a day care in Winnebago County.
Onsets were on October 31 and November 7. Both were culture positive. One
was hospitalized. Both were 3 year olds. One was male and one was female.
Both had diarrhea and fever and one had vomiting.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
July
August
October
Counties of outbreaks
Champaign
Cook
Morgan
Winnebago
209
Confirmed
5
88
18
2
0
2
2
1
1
1
1
2
S. aureus, Methicillin Resistant (MRSA)
Background
Methicillin resistant S. aureus (MRSA) can cause skin and soft tissue infections.
These infections can cluster in various situations including sports teams, prisons and
other locations where crowding and close contact between persons occurs.
Case definition
Two or more laboratory confirmed MRSA cases with a common epidemiologic
link would be needed to be considered a confirmed outbreak.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2006 – One confirmed outbreak was
reported.
• Number of cases – Four cases were reported as part of one outbreak.
• Individual Outbreak Description
o A cluster of MRSA skin and soft tissue infections occurred in four college
students in Dupage County from August to October. Three tested positive
for MRSA. Two were members of the college swim team and two were
residents in the same residence hall. No hospitalizations or fatalities were
reported.
MRSA
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
August
Counties of outbreaks
DuPage
Confirmed
1
4
0
0
1
1
Streptococcus, Group A
Background
Invasive Group A Streptococcus infection involves persons with clinically
compatible illness and cultures confirmed from a sterile site. Clusters of invasive Group
A Streptococcus infection can be identified in group settings, especially long-term care
facilities.
Case definition
For invasive Group A Streptococcus outbreaks, a confirmed outbreak requires
culture confirmation of two or more cases of sterile site group A Streptococcus in
persons with a common epidemiologic link. For an outbreak of non-invasive Group A
Streptococcus at least 10 persons with a common epidemiologic link must be clinically
210
compatible and five test positive for Group A Streptococcus.
Descriptive epidemiology
• Number of outbreaks in 2006 – Two outbreaks of invasive Group A Streptococcus
were reported. Both were in long-term care facilities. Four cases were known to
have been hospitalized and three fatalities were known to have occurred.
• Individual outbreak descriptions
o There were three cases of invasive group A streptococcus in a long-term care
facility in Coles county in August. At least two cases were hospitalized and at
least one was fatal. The onsets ranged from August 1 through August 11.
o In December a cluster of two cases of invasive group A streptococcus were
reported in residents of a long-term care facility in Chicago. Onsets of cases
were December 3 through December 4. Both cases were hospitalized and
fatal. The isolates were emm type 2.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
August
December
Counties of outbreaks
Coles
Cook
Confirmed
2
5
2.5
4
3
1
1
1
1
Alcaligenes xylosoxidans
Background
This organism has been associated with contaminated solutions like intravenous
solutions, hemodialysis fluids or irrigation fluids. Bacteremia is the most commonly
reported infection. It can be normal flora of the ear and gastrointestinal tract.
Case definition
A confirmed outbreak would be multiple cases of A. xylosoxidans in a single
facility.
Descriptive epidemiology
• Number of outbreaks in 2006 – One outbreak of A. xylosoxidans was reported
• Individual outbreak descriptions
o There were 10 cases of A. xylosoxidans reported at a hospital in LaSalle
County. Patients had fever. There was a statistically significant association
with the use of morphine administered by patient controlled analgesic (PCA).
There was also a statistically significant association with one particular health
care worker who started or changed the patient PCA. Blood cultures were
211
collected from January 8 to July 4. No fatalities occurred. Onsets of illness
were from December 25, 2005, through July 15, 2006. Ages ranged from 23
through 85 (mean=59 years). Six were female and four were male.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
Counties of outbreaks
Lasalle
Confirmed
1
10
-10
0
1
1
Serratia marcescens
Background
S. marcescens is the species of Serratia most commonly seen in human
infections. This organism is common in the environment. S. marcescens can cause a
wide variety of nosocomial infections. The most common site of infection is the urinary
tract but it is also frequently isolated from wounds and the respiratory tract.
Case definition
A confirmed outbreak would be a report of multiple cases of S. marcescens in a
single facility within a short period of time.
Descriptive epidemiology
• Number of outbreaks in 2006 – One outbreak of S. marcescens was reported
• Individual outbreak descriptions
o There were four cases of S. marcescens reported at a hospital neonatal
intensive care unit in Sangamon County. Two pods were affected. In the first
pod, culture was positive from eye drainage in one baby and from sputum in
another baby. In the second pod, the organism was isolated from eye
drainage in one baby and from blood in the other baby. Two additional babies
had screening tests positive but were asymptomatic. Onsets of illness ranged
from November 17, 2006, through January 12, 2007.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
November
Counties of outbreaks
Sangamon
212
Confirmed
1
4
--0
1
1
Viral Outbreaks
Viral gastroenteritis
Noroviruses are a common cause of gastroenteritis in the United States.
Estimates are that 23 million people are affected by noroviruses in the United States
each year. There are five genogroups (1-5). Genogroup G1 (Norwalk virus,
Southampton virus and Desert shield virus), G2 (Toronota virus, Mexico virus, Hawaii
virus, Bristol virus, Lordsdale virus, camberwall virus, Snow Mountain agent and
Melksham virus) and genogroup G4 infect humans, genogroup G3 has been found in
cattle and genogroup G5 has been identified in mice. Sapoviruses have only been
identified in humans, especially children.
Noroviruses are transmitted through consumption of contaminated food or water,
directly from person to person and from airborne droplets produced during vomiting.
The most common method of spread is via the fecal-oral route. The virus is excreted in
stool and vomitus for up to 10 days. The incubation period and duration of illness
ranges from 24 to 48 hours. Duration of illness ranges from 12 to 60 hours. Virus
shedding peaks 25 to 72 hours after exposure to the virus. Within 48 to 72 hours after
symptom onset, virus concentration in the stool declines below levels detectable by
electron microscopy. Short-term immunity occurs after infection. Vomiting, diarrhea,
headache and body aches are commonly reported.
Humans are the only known reservoir for these viruses. Characteristics of the
virus that facilitate spread include low infectious dose, high concentration of virus in
stool, strain diversity, environmental stability and prolonged shedding. Illness caused by
norovirus can be suspected based on incubation period, duration of illness, symptoms
or by identification of the organism in stool. Noroviruses can survive freezing and
temperatures of up to 60 C and can survive chlorine levels up to 10 ppm (that exceeds
what is normally present in public water systems).
Outbreaks are not uncommon in closed settings, such as detention facilities,
cruise ships, long-term care facilities and hospitals.
The virus cannot be grown in cell culture; a polymerase chain reaction (PCR) test
is used to diagnose norovirus. Testing for viral gastroenteritis in humans is not useful for
screening individual samples but is useful when multiple samples are available in an
outbreak. Norovirus can be present in stools for up to a week after illness onset.
Immunity is short-lived and appears to be strain specific. Since there are so many
strains, individuals can be repeatedly infected by noroviruses during their lifetime.
Case definition
Several laboratory tests may help to confirm an outbreak related to norovirus.
These include positive results on RT-PCR, visualization of small round structured virus
(SRSV) in electron microscopy of stool from ill individuals, or a fourfold rise in antibody
titer to norovirus seen in acute and convalescent sera in most serum pairs. Multiple
samples are needed from each outbreak to provide sufficient specimens to verify the
causative agent as norovirus. An outbreak is considered confirmed when at least two ill
persons have positive laboratory results and have a common epidemiologic link. A
suspect outbreak can be identified in persons who have a clinically compatible illness
213
(diarrhea and vomiting) and a short duration of illness with few hospitalizations and less
than three persons testing negative for norovirus and less than two patients testing
positive for the pathogen.
Descriptive epidemiology
Number of outbreaks reported in Illinois in 2006 – Forty suspected outbreaks of
norovirus gastroenteritis, based on clinical syndrome, incubation period and duration of
illness and 66 laboratory confirmed outbreaks were reported. Confirmed norovirus
outbreaks affected 3,111 people who experienced compatible illness (mean = 47 ill
persons per outbreak; range four to 228). Suspect norovirus outbreaks affected 1,680
persons (mean = 42; range: three to 162). The 66 confirmed norovirus outbreaks
occurred in the counties of Adams (one), Bureau (one), Champaign (one), Cook (24),
DeKalb (one), Dupage (two), Fulton (1), Grundy (one), Kane (two), Lawrence (one),
Livingston (one), Macon (two), Macoupin (two), Madison (three), Marion (2), Massac
(one), Morgan (four), Moultrie (one), Richland (one), Rock Island (one), Sangamon
(two), St Clair (one), Whiteside (four), Will (one), Williamson (one) and Winnebago
(four). Genotyping information was available on 63 confirmed outbreaks and nine
suspect outbreaks. Two were G1 (one confirmed and one suspect outbreak), 67 were
G2 (59 confirmed and eight suspect outbreaks) and three were both G1 and G2 (3
confirmed). Confirmed outbreaks resulted in 79 hospitalizations and no fatalities.
Suspect norovirus outbreaks resulted in 19 hospitalizations and no fatalities. The sites
of confirmed outbreaks were long-term care facilities (41), hospital (19), day care (two)
and one each for assisted living, choir camp, a multiple type of senior living facility and
residential facilities. Suspect norovirus outbreaks occurred in long-term care facilities
(24), school (five), assisted living (three), retirement community (three), day care (two)
and one each for hospital, hotel convention center and developmentally delayed facility.
The number of days of duration of the outbreak at the facilities were 14 for confirmed
outbreaks and 11 days for the suspected outbreaks.
•
Individual descriptions of confirmed outbreaks
o Nineteen persons (18 residents, one staff) developed gastrointestinal
illness at a long-term care facility in DuPage County in January. Two of
three persons tested were positive for norovirus G2. Onsets of illness
were from January 29 through February 2. Three persons were
hospitalized and there were no fatalities. All persons reported diarrhea.
o In January, 15 persons (8 residents and 7 staff) were affected by norovirus
in a long-term care facility in Winnebago County. There were 80 residents
at the facility. Onsets ranged from January 14 through February 1.
o In February, 21 persons (19 residents, 2 staff) at a long-term care facility
in Joliet were reported with gastrointestinal illness. Four of five specimens
tested positive for norovirus G2. It is unknown if anyone was hospitalized.
o Sixty-eight persons (25 staff, 43 residents) at a LTC facility in Kane
County reported gastrointestinal illness in February. Illness onsets ranged
from February 19 to February 27. One stool was positive for G1 and one
214
o
o
o
o
o
o
o
o
o
o
o
for G1 and G2. Five residents were sent to the hospital but it is unknown if
they were hospitalized.
In February, 25 staff and 63 residents were affected with gastrointestinal
illness at a long-term care facility in Grundy County. Sixty percent had
diarrhea and 45 percent had vomiting. Five persons were hospitalized.
Three of three stool specimens were positive for norovirus G2. Onsets
ranged from February 25 through March 4.
A hospital in Kane County reported 43 persons (4 visitors, 18 staff and 21
patients) with gastrointestinal illness. These illnesses occurred after
several residents of a LTC facility had been treated in the ED or admitted
to the hospital between February 27 and 28. Illnesses at the hospital
ranged from March 2 through March 7. Five of seven specimens were
positive for Norovirus G2.
In March, 19 illnesses (1 staff, 18 residents) occurred in a long-term care
facility in Skokie, Illinois. Illnesses ranged from March 5 through March 8.
Twelve of 20 stools tested positive for norovirus G2. Five persons were
hospitalized; there were no fatalities.
Eighteen (17 residents, 1 staff) persons from a long-term care facility in
Skokie, Illinois were reported with gastrointestinal illness in March. Illness
onsets ranged from March 2 through March 8. No persons were
hospitalized. Four of seven persons were tested positive for norovirus G2.
Thirteen staff and five patients at a Cook County hospital experienced
diarrhea and/or vomiting in March. Three of three persons tested positive
for norovirus G2.
Five persons were confirmed with norovirus G2 at a hospital in Chicago.
No information is available on the total number ill. Illnesses began around
March 15.
A hospital in Cook County reported 228 persons (100 staff and 128
residents) ill with norovirus G2. Onsets began on March 18 and ended on
April 14.
A long-term care facility in Cook County reported 99 persons ill (75
residents, 25 staff) with norovirus G2 in March. Onsets began on March 6
and continued through April 5. Eight of eight stools tested positive for
norovirus. Six persons were hospitalized. Fifty percent reported diarrhea
and 32 percent reported vomiting.
In March, a long-term care facility in Cook County reported 29 persons ill
(12 staff, 17 residents) with norovirus G2. Two of three tested were
positive for norovirus G2. Three residents were hospitalized. Onsets
ranged from March 13 through April 7. Eighty-six percent had diarrhea and
59 percent reported vomiting.
There were 101 persons (19 staff, 82 residents) reported ill with norovirus
G2 in a hospital in Cook County in March. Onset dates ranged from March
29 through April 12. Twenty-two of 36 stool specimens from ill persons
tested positive for norovirus G2. There were no fatalities.
Thirty-three persons (29 residents, four staff) were reported with
gastrointestinal illness at a long-term care facility in Cook County in
215
o
o
o
o
o
o
o
o
o
o
o
March. Onsets ranged from March 25 through March 31. Three of three
stools tested were positive for norovirus. No hospitalizations were
reported.
A hospital in Cook County reported 91 illnesses (66 staff, 25 patients) in
April. Three of three stools tested were positive for norovirus G2. Onsets
occurred from April 3 through April 27.
Four residents at a long-term care facility in Cook County were affected by
norovirus G2. Three of three stools tested positive. There were an
unknown number of hospitalizations.
In April, 95 persons (38 staff, 57 residents) were reported with
gastrointestinal illness in a long-term care facility in Cook County. Three of
three stools were positive for norovirus G2. There were no
hospitalizations.
At least 13 persons were affected with gastrointestinal illness at a longterm care facility in Cook County. Seven of 13 stools tested positive for
norovirus G2. No hospitalizations were reported.
In April, an estimated 119 persons were ill with gastrointestinal illness in a
Chicago long-term care facility. Forty-one staff and 78 residents were
reported to be ill. Five persons tested positive for norovirus G2. Five
persons were hospitalized.
Twenty-two persons (11 staff, 11 patients) at a hospital in Chicago
developed gastrointestinal illness in April. Illness onsets ranged from April
29 through May 7. Norovirus G2 was identified in nine of 10 stool
specimens.
From April 15 to May 4, 37 persons (nine staff, 28 residents) developed
gastrointestinal illness in an assisted living facility in DeKalb County.
There were 101 exposed individuals. Five persons tested positive for
norovirus G2. Fifteen were hospitalized.
Twenty persons (3 staff, 17 residents) experienced diarrhea at a long-term
care facility in Winnebago County in May. Six of 12 stools tested positive
for norovirus G2. Onsets of illness ranged from May 1 through May 8. All
ill persons had diarrhea and 11 percent experienced vomiting.
Five patients in the skilled nursing unit at a hospital developed norovirus
G2 in May in Adams County. Three of five stool specimens tested positive.
Onsets of illness ranged from May 8 through May 10.
Twelve persons attending a party at a LTC facility in Rock Island
developed gastrointestinal illness in May 2006. Illness onsets ranged from
May 7 to May 8. Illnesses had started before the party and transmission
was believed to be person-to-person. Some of the ill persons were
visitors, some staff and some were residents. One person was
hospitalized. Two stools were positive for G2 and two were weakly
positive for G1 and five were tested.
In May, four persons tested positive for norovirus at a hospital in
Sangamon County. Illness onsets ranged from May 9 through May 16.
Thirty six persons (19 staff and 17 residents) became ill.
216
o Sixty persons (20 staff and 40 residents) of a long-term care facility in
Winnebago County developed diarrhea and/or vomiting. Three of three
tested positive for norovirus G2. Onsets of illness ranged from May 17
through May 25. One person was hospitalized.
o Thirteen residents of a long-term care facility in Winnebago County
reported gastrointestinal illness in May. Onsets of illness continued from
May 23 through May 24. No hospitalizations were reported. Five of five
stools tested positive for norovirus.
o In June, 42 persons (17 staff and 23 residents) of a long-term care facility
in Whiteside County developed gastrointestinal illness. Five of five stools
tested positive for norovirus G2. Onsets ranged from June 9 through June
16. Seventy-four percent reported diarrhea and 57 percent vomiting. The
number of hospitalizations was unknown.
o There were 118 of 700 show choir participants who became ill in June in
Macon County. Five of five tested positive for norovirus G2. Onsets of
illness ranged from June 19 through June 24. No hospitalizations were
reported.
o In August, 43 persons (nine staff and 34 residents) were ill with
gastrointestinal illness in a long-term care facility in Lawrence County.
Five of eight tested positive for norovirus G2. Eighty-eight percent of the ill
persons experienced diarrhea and 35 percent had vomiting. No
hospitalizations were reported.
o Forty-eight persons (18 staff, 30 residents) of a long-term care facility in
Massac County reported gastrointestinal illness between September 14
and September 27. Three of five stools tested positive for norovirus G2.
There were 180 persons exposed. No hospitalizations were reported.
o In September, 38 persons (14 staff, 24 residents) in a long-term care
facility in Madison County developed diarrhea and/or vomiting. Five of five
stools tested positive for norovirus G2. Four ill persons were hospitalized.
All had diarrhea and 50 percent reported vomiting. Onsets of illness
ranged from September 28 through October 28.
o Gastrointestinal illnesses started on August 15 in a long-term care facility
in Marion County. Twenty staff and residents were ill. Two of four tested
positive for norovirus G2. The number of hospitalizations was unknown.
o Ninety-nine persons (26 staff, 73 residents) became ill at a Morgan County
long-term care facility in October. Two of three stools tested positive for
norovirus G2. Onsets ranged from October 2 through October 31. No
hospitalizations were reported.
o In October, a norovirus G2 outbreak occurred in a long-term care facility in
Fulton County. Seventy-four persons (27 staff, 47 residents) were
affected. Onsets of illness ranged from October 24 through October 31.
Four of six stools tested were positive for norovirus G2. All cases reported
vomiting and 75 percent reporting diarrhea. One person was hospitalized.
o Hospital staff (28) and patients (eight) developed gastrointestinal illness
from October 20 through November 1 in a hospital in Marion County. Five
217
o
o
o
o
o
o
o
o
o
o
of five stools tested positive for norovirus G2. A patient was initially
admitted with diarrhea and vomiting.
In October there were 40 persons, including staff, attendees and
household members of attendees) of 118 exposed individuals who
developed gastrointestinal illness in a Morgan County day care. Two of
four stools tested positive for norovirus G2. Illness onsets ranged from
October 19 through November 13. No hospitalizations were reported.
A total of 47 persons (26 staff, 21 residents) became ill at a long-term care
facility in St Clair County in October. Eight of nine stools were positive for
norovirus G2. Onsets of illness ranged from October 24 through October
30. No hospitalizations or fatalities were reported.
From October 30 through November 9, 58 (30 staff, 28 residents) were ill
with gastrointestinal illness at a long-term care facility in Whiteside
County. Three of five stools tested were positive for norovirus G2. Cases
reported diarrhea (82 percent) and vomiting (71 percent). Three persons
were hospitalized.
In November, 129 of 178 exposed persons at a long-term care facility in
Moultrie county developed gastrointestinal illness. Three of three stools
were positive for norovirus G2. Fifty-four staff and 75 residents became ill
between November 1 and November 20. No hospitalizations or fatalities
were reported.
In November, a norovirus G2 outbreak was reported in Morgan County.
Five staff and 25 attendees or their families reported gastrointestinal
illness. There were 110 exposed persons at the day care. Two of five
stools were positive for norovirus G2. No hospitalizations or fatalities
occurred. Onsets of illness ranged from November 8 through November
20.
At a hospital in Cook County in November, 13 persons (3 staff, 10
patients) became ill with gastrointestinal disease. Four of 10 persons
tested positive for norovirus G2.
Five persons (one staff, four patients) were ill from November 8 through
November 14 at a hospital transitional care unit in Morgan County. Two of
two stools tested positive for norovirus G2. All persons had both diarrhea
and vomiting.
Fifty-nine of 160 exposed persons at a hospital in Macoupin County
developed gastrointestinal illness. Four of five tested were positive for
norovirus G2. Onsets of illness ranged from November 12 through
December 8.
From November 21 through December 14, 21 persons (15 staff, six
residents) at a Sangamon County hospital developed gastrointestinal
illness. Five of eight persons tested positive for norovirus G2.
In a Cook County hospital, 88 persons (72 staff, 16 patients) became ill
with gastrointestinal illness in November. Eleven of 15 persons tested
positive for norovirus G2.
218
o From November 29 through December 17, 126 persons (35 staff, 91
residents) became ill with gastrointestinal illness in a Madison County
long-term care facility. Two of three stools were positive for norovirus G2.
o Twenty-two individuals (12 staff, 10 residents) developed gastrointestinal
illness at an assisted living facility in Williamson County in November. Two
of three stools were positive for norovirus G2. Six persons were
hospitalized. Illness onsets ranged from November 30 through December
6.
o From November 26 through December 14, 23 persons (10 staff, 13
residents) from a long-term care facility in Champaign County were
affected with norovirus. Three of three stools tested positive for norovirus
G2. Sixty-two percent reported vomiting and 81 percent reported diarrhea.
No hospitalizations were reported.
o In December, five of five stools submitted from a long-term care facility in
Bureau County tested positive for norovirus G2. Sixty-six (30 staff, 36
residents) of 124 exposed persons developed gastrointestinal illness. One
person was hospitalized.
o Thirty-three persons (17 staff, 16 patients) at a hospital long-term care unit
in Richland County were affected by gastrointestinal illness. Illness onsets
ranged from December 1 through December 8. Sixty-three percent
reported vomiting and 88 percent diarrhea. Three of four tested positive
for norovirus G1. No hospitalizations were reported.
o In December, 24 (four staff, 20 residents) of a long-term care facility in
Livingston County developed diarrhea and/or vomiting. Four of four
persons tested positive for norovirus G2. Illness onsets ranged from
December 3 through December 6. No hospitalizations were reported.
o From December 2 through December 12, 14 persons (four staff, 10
residents) were ill with gastrointestinal illness at a Chicago long-term care
facility. Four of five tested positive for norovirus G2. No hospitalizations
were reported.
o In DuPage County, 21 persons (six staff, 15 residents) reported
gastrointestinal illness at a hospital long-term care facility. Eight of eight
persons tested positive for norovirus G2. Symptoms included vomiting (57
percent) and diarrhea (81 percent). One person was hospitalized and no
fatalities were reported. Illness onsets ranged from December 3 through
December 19.
o From December 9 through December 14, 17 persons (two staff, 15
residents) at a Chicago hospital developed gastrointestinal illness. Seven
of seven persons tested positive for norovirus G2.
o Six of seven stools tested positive for norovirus G2 in an outbreak
involving staff at a hospital in Whiteside. From December 3 through
January 11, 76 staff became ill. None were hospitalized.
o A Chicago long-term care facility reported an outbreak of norovirus G2
from December 1 through December 25. Four of six persons tested
positive. Four persons were hospitalized. Twenty-six persons (nine staff,
17 residents) became ill.
219
o In December, 45 persons (23 staff, 22 patients) of a hospital in Whiteside
County developed gastrointestinal illness. Two of two tested positive for
norovirus G2. There were 172 persons exposed. Seventeen of the ill were
in the long-term care area. Onsets of illness ranged from December 2
through December 21. The number of hospitalizations were unknown.
o Forty-three persons (16 staff, 27 residents) became ill at a long-term care
facility in Macoupin County. Eight of nine tested positive for norovirus G2.
Ninety-five percent reported diarrhea and 98 percent vomiting. Onsets of
illness ranged from December 3 through December 19. No
hospitalizations were reported.
o From December 11 through December 19, 38 persons (five staff, 33
residents) were identified with gastrointestinal illness at a long-term care
facility in Macon County. Two of seven persons tested positive for
norovirus G2. Two persons were hospitalized.
o Eighteen staff at a hospital in Chicago in December reported
gastrointestinal illness. Two of two tested positive for norovirus G1 and
G2. None were hospitalized and no fatalities were reported. Onsets of
illness ranged from December 12 through December 18.
o In December, 58 persons (8 staff, 50 residents) of an assisted living and
independent living facility became ill. Two tested positive for norovirus.
Nine were hospitalized and there were no reported fatalities. Onsets of
illness ranged from December 7 through 30. Ninety-one percent reported
diarrhea and 74 percent reported vomiting.
o From December 18 through December 27, 48 persons (17 staff, 31
residents) of a long-term care facility in Madison County were reported
with gastrointestinal illness. None were hospitalized and none were fatal.
Three of five persons tested positive for norovirus G2.
o A Chicago long-term care facility reported illness in 42 persons (13 staff,
29 residents) from December 30, 2006 through January 9, 2007. Five of
five persons tested positive for norovirus G2. Two persons were
hospitalized.
o From December 21, 2006, through January 12, 2007, 32 gastrointestinal
illnesses were reported in persons at a long-term care facility in Cook
County. Eight of 16 tested positive for norovirus G2. Fifteen were staff
members and 17 were residents. Three were hospitalized and no fatalities
were reported.
Norovirus
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
220
Confirmed
66
3,111
Suspected*
40
1,680
79
0
42
0
2
0
February
March
April
May
June
July
August
September
October
November
December
3
10
7
6
2
0
2
2
6
10
16
5
3
4
2
1
1
0
1
0
9
14
Adams
Bureau
Champaign
Cook
DeKalb
DuPage
Ford
Fulton
Grundy
Jo Daviess
Kane
Lake
Lawrence
Livingston
Macon
Macoupin
Madison
Marion
Massac
McHenry
McLean
Montgomery
Morgan
Moultrie
Ogle
Richland
Rock Island
St Clair
Saline
Sangamon
Schuyler
Tazewell
Williamson
Whiteside
Will
Wlliamson
Winnebago
1
1
1
24
1
2
0
1
1
0
2
0
1
1
2
2
3
2
1
0
0
0
4
1
0
1
1
1
0
2
0
0
1
4
1
1
4
0
1
0
7
0
4
1
0
0
4
4
2
1
0
1
0
0
0
0
1
1
2
1
0
1
0
0
0
1
3
1
1
0
0
1
0
2
Counties of outbreaks
221
Facility Type
Long-term care
Hospital
Retirement facility
Day care
Hotel
School
Show choir camp
Assisted living
DD facility
Residential facility
Assisted living and independent living
41
19
0
2
0
0
1
1
0
1
1
24
1
3
2
1
5
0
3
1
0
0
Parasites
Cryptosporidiosis
Background
Outbreaks of cryptosporidiosis are typically associated with recreational or
drinking water exposure or day care centers. Transmission can be fecal-oral, animal to
person, waterborne and foodborne.
Descriptive epidemiology
• Number of outbreaks in 2006 – One outbreak was reported.
• Individual outbreak descriptions
One outbreak of suspect cryptosporidiosis was reported in a community in Jo
Daviess County in June. Seventeen people from five households on the same
street became ill. One tested positive for cryptosporidiosis of five tested. The
source was unknown. Onsets of illness ranged from June 9 through August 15.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
June
Counties of outbreaks
Jo Daviess
Suspected
1
17
0
0
1
1
Fungi
Histoplasmosis
Background
Outbreaks of histoplasmosis have been identified previously in Illinois and are most
commonly associated with occupational exposures, such as bridge repair or earth
moving activities.
222
Descriptive epidemiology
• Number of outbreaks in 2006 – One outbreak was reported.
• Individual outbreak descriptions
An outbreak of histoplasmosis occurred in September in two male Chicago
residents of six persons who traveled to Kentucky to repair a home. They had
contact with bird droppings. The case ages were 19 and 46. Both persons were
hospitalized and survived.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
September
Counties of outbreaks
Cook
Confirmed
1
2
2
0
1
1
Unknown
Descriptive Epidemiology
• Number of outbreaks in 2006 – Three outbreaks with unknown etiology were
reported in 2006.
• Individual outbreak descriptions
A cluster of 66 cases of gastrointestinal illnesses occurred in a school in
LaSalle County.
A cluster of five persons became ill at a work site in Adams County in
August. Onsets of diarrhea ranged from August 31 through September 6.
Two persons tested negative for norovirus.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
March
August
Counties of outbreaks
Adams
LaSalle
223
Unknown
2
71
35
0
0
1
1
1
1
Figure 109. Number of Non-foodborne, Non-waterborne Outbreaks Reported in Each
Illinois County, 2006
Jo DaviessStephensonWinnebago McHenry Lake
5
0
8
2
1
Boone
0
Carroll
Ogle
0
1
Kane
DeKalb
6 DuPageCook
1
7
34
Whiteside
Lee
4
0
Kendall
0
Will
Rock Island
Bureau
Henry
2
La
Salle
1
2
Grundy
0
2
Putnam
Mercer
1
Kankakee
0
0
Stark
0
Marshall
0
0
Knox
Livingston
0
HendersonWarren
1
Peoria
0
Woodford
Iroquois
0
0
0
1
Ford
McDonough
1
0
McLean
Fulton
Tazewell
Hancock
1
1
1
0
Mason
ChampaignVermilion
De Witt
Schuyler
0
Logan
0
2
0
1
0
Menard
Piatt
Adams Brown
Cass
0
0
2
0
0
Macon
Douglas
Morgan Sangamon
3
Edgar
0
6
6
Moultrie
Scott
Pike
0
1
0
Christian
0
Coles
0
1
Shelby
Greene
Clark
0
Cumberland 0
0
Macoupin
0
Montgomery
Calhoun
2
2
Jersey
0
Effingham
Jasper Crawford
Fayette
0
0
0
0
0
Bond
Madison
0
Clay
3
RichlandLawrence
0
2
1
Clinton Marion
2
0
St. Clair
Wabash
Wayne
1
0
Washington
0
Jefferson
Edwards
Monroe
0
0
0
0
White
Randolph Perry
0
0
Franklin
0
0
Jackson
SalineGallatin
0
0
Williamson 1
1
Hardin
Union
0
Pope
0
Johnson 0
Massac
Pulaski
0
1
0
Alexander
0
224
Table 19.
Non-foodborne and Non-waterborne Outbreaks in Illinois in 2006.
Exposure
IDPH Log
Number
IL2006-90
# lab
positive
10
County
Exp
ILL/Exp
# Staff/ #
Residents
or Students
Symptoms
*
Transmission
Type
Agent Implicated
Status
Location of
outbreak
Ottawa
LaSalle
10/unk
0/10
F
Possibly thru
medication drip
Alcaligenes
xylosoxidans
C
Hospital
2/1
Rockford
Winnebago
15/80
7/8
D,V
Person-person
Norovirus
C
LTC
1/21
2/2
Naperville
Dupage
19/149
1/18
D
Person-person
Norovirus G2
C
LTC
2/4
2/15
Cicero
Cook
59/unk
D,V
Person-person
Norovirus
S
LTC
2/8
2/14
Plainfield
Will
35/unk
D,V
Person-person
Norovirus
S
LTC
2/10
2/14
Palos Heights
Cook
60/unk
D,V
Person-person
Norovirus
S
LTC
Cook
13/unk
0/13
D,V
Person-person
Norovirus G2
S
LTC
First
Onset
Last Onset
City
1/1
7/1
1/14
3
IL2006-52
1
IL2006-10
0
IL2006-53
0
IL2006-54
0
IL2006-55
0
2/13
est
IL2006-11
2
IL2006-14
2/19
2/27
Elgin
Kane
68/139
25/43
D,V
Person-person
Norovirus G1 &
G2
C
LTC
2/20
2/24
Lisle
DuPage
57/81
20/37
D,V
Person-person
Norovirus
S
LTC
Joliet
Will
21/unk
2/19
D,V
Person-person
Norovirus G2
C
LTC
0
IL2006-16
4
IL2006-13
2/22
3
IL2006-15
2/25
3/4
Morris
Grundy
88/104
25/63
D,V
Person-person
Norovirus G2
C
LTC
3/1
3/2
Lostant
LaSalle
66/96
5/61
D,V
Person-person
Unknown
U
School
0
IL2006-18
225
5
IL2006-19
3/2
3/7
Elgin
Kane
43/unk
18/21, 4
visitors
D,V
Person-person
Norovirus G2
C
Hospital
3/2
3/8
Skokie
Cook
18/102
1/17
D,V
Person-person
Norovirus G2
C
LTC
3/3
4/4
Evanston
Cook
25/unk
5/20
D,V
Person-person
Norovirus G2
S
LTC
3/5
3/8
Skokie
Cook
19/84
1/18
D,V
Person-person
Norovirus G2
C
LTC
Oak Lawn
Cook
18/unk
13/5
D,V
Person-person
Norovirus G2
C
Hospital
Evanston
Cook
99/455
24/75
D,V
Person-person
Norovirus G2
C
LTC
East Dundee
Kane
30/unk
0/30
D,V
Person-person
Norovirus
S
Retirement
community
Evanston
Cook
29/157
12/17
D,V
Person-person
Norovirus G2
C
LTC
Chicago
Cook
5/unk
D,V
Person-person
Norovirus G2
C
Hospital
4
IL2006-21
1
IL2006-44
12
IL2006-20
3
IL2006-23
3/6
7
IL2006-31
3/6
4/5
0
IL2006-29
3/11
2
IL2006-36
3/13
4/7
5
IL2006-24
3/15
22
IL2006-28
3/18
4/14
Park Ridge
Cook
228/unk
100/128
D,V
Person-person
Norovirus G2
C
Hospital
3/22
3/31
St Charles
Kane
51/82
11/38, 1
visitor
D,V
Person-person
Norovirus G2
S
LTC
3/25
3/31
Skokie
Cook
33/unk
4/29
D,V
Person-person
Norovirus G2
C
LTC
3/29
4/12
Arlington
Heights
Cook
101/unk
19/82
D,V
Person-person
Norovirus G2
C
Hospital
4/3
4/27
Oak Forest
Cook
91/unk
66/25
D,V
Person-person
Norovirus G2
C
Hospital
1
IL1006-32
3
IL2006-41
22
IL2006-37
2
IL2006-48
226
0
IL2006-46
4/5
4/11
Rockford
Winnebago
42/120
Desplaines
Cook
13/unk
1/41
D,V
Person-person
Norovirus
S
LTC
D,V
Person-person
Norovirus G2
C
LTC
7
IL2006-58
4/10
5
IL2006-59
4/11
5/16
Chicago
Cook
119/120
41/78
D,V
Person-person
Norovirus G2
C
LTC
4/14
4/15
Evanston
Cook
3/unk
0/3
D,V
Person-person
Norovirus G2
S
Day care
4/15
5/4
Dekalb
37/101
9/28
D,V
Person-person
Norovirus G2
C
Residential
facility
Des Plaines
Cook
4/unk
0/4
D,V
Person-person
Norovirus G2
C
LTC
Geneva
Kane
40/unk
14/26
D,V
Person-person
Norovirus
S
LTC
4/23
South Holland
Cook
95/unk
38/57
D,V
Person-person
Norovirus G2
C
LTC
4/25
Niles
Cook
12/unk
Unk/12
D,V
Person-person
Norovirus
S
Retirement
facility
Chicago
Cook
22/unk
11/11
D,V
Person-person
Norovirus G2
C
Hospital
Winnebago
20/382
3/17
D
Person-person
Norovirus G2
C
LTC
1
IL2006-51
5
IL2006-62
3
IL2006-49
4/18
0
IL2006-56
4/18
4/25
3
IL2006-57
0
IL2006-60
9
IL2006-63
4/29
5/7
5/1
5/8
5/5
5/16
Springfield
Sangamon
30/350
D,V
Person-person
Norovirus
S
Hotel
convention
5/7
5/8
Rock Island
Rock Island
12/42
D,V
Person-person
Norovirus G1&G2
C
LTC
5/8
5/10
Quincy
Adams
5/unk
D,F,V
Person-person
Norovirus G2
C
Hospital
6
IL2006-67
0
IL2006-72
2
IL2006-69
3
IL2006-68
227
0/5
4
IL2006-70
5/9
5/16
Springfield
Sangamon
36/50
19/17
D,V
Person-person
Norovirus
C
Hospital
5/17
5/25
Durand
Winnebago
60/70
20/40
D,V
Person-person
Norovirus G2
C
LTC
5/23
5/24
Rockford
Winnebago
13/73
0/13
D,V
Person-person
Norovirus G2
C
LTC
Elgin
Kane
27/186
1/26
D,V
Person-person
Norovirus
S
School
D
Unknown
Cryptosporidiosis
S
Neighborhood
D,V
Person-person
Norovirus G2
C
LTC
3
IL2006-73
5
IL2006-76
0
IL2006-75
5/24
1
IL2006-108
6/9
8/15
Galena
JoDaviess
17/19
6/9
6/16
Prophetstown
Whiteside
42/64
Springfield
Sangamon
8/unk
D,V
Person-person
Norovirus
S
Hospital
D,V
Person-person
Norovirus G2
C
Choir camp
5
IL2006-80
17/23
0
IL2006-79
6/10
5
IL2006-85
6/19
6/24
Decatur
Macon
118/700
7/12
7/21
Rockford
Winnebago
3/unk
0/3
D
Person-person
S. sonnei
C
Day care
7/22
8/6
Chicago
Cook
6/12
1/5
D
Person-person
S. sonnei
C
Day care
7/26
7/31
Decatur
Macon
14/unk
2/12
D,V
Person-person
Norovirus G2
S
Assisted living
Charleston
Coles
3/unk
0/3
Invasive
Unknown
S. pyogenes
C
LTC
2
IL2006-93
6
IL2006-102
1
IL2006-95
3
IL2006-104
8/1
3
IL2006-200
8/1
10/28
Wheaton
Dupage
4/unk
0/4
SSTI
Person-person
MRSA
C
College
8/7
9/7
Jacksonville
Morgan
74/146
8/66
D,F
Person-person
S. sonnei
C
Day care
2
IL2006-110
228
2
IL2006-107
8/15
Marion
Marion
20/unk
D,V
Person-person
Norovirus G2
C
LTC
3
IL2006-116
8/23
8/25
Champaign
Champaign
3/50
0/3
D
Person-person
S. sonnei
C
Day care
8/25
8/31
Bridgeport
Lawrence
43/unk
9/34
D,V
Person-person
Norovirus G2
C
LTC
8/31
9/6
Camp Point
Adams
5/unk
5/0
5
IL2006-114
0
IL2006-115
2
IL2006-125
9/12
9/23
9/14
9/17
9/14
9/27
9/28
Chicago
residents
D
Unknown
Unknown
U
Work site
F,
shortness
of breath
Inhalation
Histoplasma
capsulatum
C
House
construction
Out-of-state
2/6
Bureau
17/unk
0/17
D,V
Person-person
Norovirus
S
LTC
Metropolis
Massac
48/180
18/30
D,V
Person-person
Norovirus G2
C
LTC
10/28
Alton
Madison
38/unk
14/24
D,V
Person-person
Norovirus G2
C
LTC
10/2
10/31
Jacksonville
Morgan
99/331
26/73
D,V
Person-person
Norovirus G2
C
LTC
10/19
11/13
Jacksonville
Morgan
40/118
9/25, 3
other
D,V
Person-person
Norovirus G2
C
Day care
10/20
11/1
Salem
Marion
36/unk
28/8
D,V
Person-person
Norovirus G2
C
Hospital
10/24
10/30
Belleville
St Clair
47/unk
26/21
D,V
Person-person
Norovirus G2
C
LTC
10/24
10/31
Canton
Fulton
74/225
27/47
D,V
Person-person
Norovirus G2
C
LTC
10/30
11/9
Morrison
Whiteside
58/126
30/28
D,V
Person-person
Norovirus G2
C
LTC
0
IL2006-119
3
IL2006-120
5
IL2006-123
2
IL2006-127
2
IL2006-131
5
IL2006-128
8
IL2006-132
4
IL2006-130
3
IL2006-137
229
2
IL2006-145
10/31
11/7
Rockford
Winnebago
2/unk
0/2
D,F,V
Person-person
Shigella sonnei
C
Day care
11/1
11/20
Sullivan
Moultrie
129/178
54/75
D,V
Person-person
Norovirus G2
C
LTC
11/8
11/26
Elizabeth
Jo Daviess
13/115
13/0
D,V
Person-person
Norovirus
S
LTC
11/8
11/14
Jacksonville
Morgan
5/unk
1/4
D,V
Person-person
Norovirus G2
C
Hospital
11/8
11/20
Jacksonville
Morgan
30/110
D,V
Person-person
Norovirus G2
C
Day care
Jacksonville
Morgan
10/103
2/8
D,V
Person-person
Norovirus
S
Day care
Carlinville
Macoupin
59/160
55/4
D,V
Person-person
Norovirus G2
C
Hospital
Park Ridge
Cook
13/unk
3/10
D,V
Person-person
Norovirus G2
C
Hospital
Person-person
Norovirus
S
School
Unknown
Serratia
marcescens
C
Hospital, NICU
3
IL2006-136
0
IL2006-204
2
IL2006-142
2
IL2006-139
0
IL2006-146
11/12
4
IL2006-143
11/12
12/8
4
IL2006-140
11/12
0
IL2006-144
11/13
11/21
Roselle
DuPage
106/unk
11/17
1/12
Springfield
Sangamon
4/unk
0/4
D,V
Eye
drainage,
bloodstrea
m
infection,
sputum
Chicago
Cook
88/unk
72/16
D,V
Person-person
Norovirus G2
C
Hospital
4
IL2006-209
11
IL2006-152
11/19
0
IL2006-157
11/20
12/1
Hopedale
Tazewell
42/80
18/24
D,V
Person-person
Norovirus
S
LTC
11/21
12/14
Springfield
Sangamon
21/123
15/6
D,V
Person-person
Norovirus G2
C
Hospital
5
IL2006-147
230
0
IL2006-148
11/22
11/28
Auburn
Sangamon
19/102
4/15
D,V
Person-person
Norovirus
S
LTC
11/26
12/14
Champaign
Champaign
23/210
10/13
D,V
Person-person
Norovirus G2
C
LTC
11/27
1/25
Warren
JoDaviess
162/578
3/159
D,V
Person-person
Norovirus
S
School
Waukegan
Lake
30/210
9/21
D
Person-person
Norovirus
S
DD facility
3
IL2006-161
0
IL2006-205
0
IL2006-167
11/27
1
IL2006-155
11/27
11/30
Lawrenceville
Lawrence
45/unk
18/27
D,V
Person-person
Norovirus
S
LTC
11/27
12/8
Eldorado
Saline
67/120
18/49
D,V
Person-person
Norovirus G2
S
LTC
11/29
12/17
Alton
Madison
126/unk
35/91
D,V
Person-person
Norovirus G2
C
LTC
11/30
12/6
Herrin
Williamson
22/80
12/10
D,V
Person-person
Norovirus G2
C
Assisted living
Park Ridge
Cook
63/unk
17/46
D,V
Person-person
Norovirus G2
S
Assisted living
1
IL2006-166
2
IL2006-171
2
IL2006-158
1
IL2006-165
12/1
3
IL2006-160
12/1
12/8
Olney
Richland
33/unk
17/16
D,V
Person-person
Norovirus G1
C
Hospital
12/1
12/8
Elmhurst
DuPage
66/unk
6/60
D,V
Person-person
Norovirus
S
Retirement
facility
12/1
12/25
Chicago
Cook
26/75
9/17
D,V
Person-person
Norovirus G2
C
LTC
12/2
12/21
Morrison
Whiteside
45/172
23/22
D,V
Person-person
Norovirus G2
C
Hospital
12/2
12/12
Chicago
Cook
14/496
4/10
D,V
Person-person
Norovirus G2
C
LTC
0
IL2006-173
4
IL2006-195
2
IL2006-179
4
IL2006-163
231
5
IL2006-156
12/2
12/10
Walnut
Bureau
66/124
30/36
D,V
Person-person
Norovirus G2
C
LTC
12/3
1/11
Sterling
Whiteside
76/925
76/0
D,V
Person-person
Norovirus G2
C
Hospital
12/3
12/4
Chicago
Cook
2/unk
0/2
Invasive
Unknown
S. pyogenes/
Invasive
C
LTC
12/3
12/6
Fairbury
Livingston
24/61
4/20
D,V
Person-person
Norovirus G2
C
LTC
12/3
12/19
Elmhurst
Dupage
21/unk
6/15
D,V
Person-person
Norovirus G2
C
Hospital LTC
12/3
12/19
Staunton
Macoupin
43/173
16/27
D,V
Person-person
Norovirus G2
C
LTC
12/4
12/20
E. Dubuque
Jo Daviess
100/525
3/97
D,V
Person-person
Norovirus
S
School
12/4
12/9
Westmont
Dupage
9/unk
0/9
D,V
Person-person
Norovirus
S
LTC
12/6
12/11
Evanston
Cook
3/unk
0/3
D
Person-person
C. difficile
C
LTC
6
IL2006-178
2
IL2006-210
4
IL2006-162
8
IL2006-164
8
IL2006-180
0
IL2006-206
0
IL2006-168
3
IL2006-183
2
IL2006-190
12/7
12/30
Oak Park
Cook
58/unk
8/50
D,V
Person-person
Norovirus
C
Assisted and
independent
living
12/8
12/15
Rockford
Winnebago
39/unk
4/35
D,V
Person-person
Norovirus
S
LTC
12/9
12/17
Vernon Hills
Lake
26/240
1/25
D,V
Person-person
Norovirus
S
Retirement
facility
12/9
12/14
Chicago
Cook
17/unk
2/15
D,V
Person-person
Norovirus G2
C
Hospital
12/11
12/19
Macon
38/87
5/33
D,V
Person-person
Norovirus G2
C
LTC
0
IL2006-185
0
IL2006-182
7
IL2006-177
2
IL2006-184
232
0
IL2006-207
12/11
1/19/07
Elizabeth
Jo Daviess
103/640
0/103
D,V
Person-person
Norovirus
S
School
12/12
12/18
Chicago
Cook
18/unk
18/0
D,V
Person-person
Norovirus G1&G2
C
Hospital
12/17
12/21
LeRoy
McLean
37/222
7/30
D,V
Person-person
Norovirus
S
LTC
12/18
12/27
Godfrey
Madison
48/unk
17/31
D,V
Person-person
Norovirus G2
C
LTC
12/18
12/29
Rushville
Schuyler
39/106
23/16
D,V
Person-person
Norovirus
S
LTC
12/21
1/12
Evanston
Cook
32/unk
15/17
D,V
Person-person
Norovirus G2
C
LTC
12/24
1/10
Litchfield
Montgomery
53/167
12/41
D,V
Person-person
Norovirus
S
LTC
12/26
12/29
McHenry
McHenry
4/98
0/4
D,V
Person-person
Norovirus G1
S
LTC
12/28
1/18
Paxton
Ford
66/149
23/43
D,V
Person-person
Norovirus G2
S
LTC
12/30
1/9
Chicago
Cook
42/180
13/29
D,V
Person-person
Norovirus G2
C
LTC
12/30
1/15
Polo
Ogle
30/95
15/15
D,V
Person-person
Norovirus
S
LTC
28/unk
28/
D,V
Person-person
Norovirus
S
LTC
2
IL2006-189
0
IL2006-192
3
IL2006-196
0
IL2006-193
8
IL2006-201
0
IL2006-212
1
IL2006-194
1
IL2006-203
5
IL2006-198
1
IL2006-199
0
IL2006-208
*
12/30
Nokomis
Montgomery
D=diarrhea, F=fever, V=vomiting, SSTI=skin and soft tissue infection
233
Table 20. Reported Cases of Infectious Disease in Illinois, 2006
Disease
Number
Disease
AIDS and HIV-report year
1,254 AIDS; Legionnaires disease
1,876 HIV
Amebiasis cases, symptomatic
75 Leprosy
Anthrax
Arbovirus infection (WNV,
Dengue, SLE, CE)
Aseptic meningitis or encephalitis
of unknown etiology
Aseptic meningitis or encephalitis
of known etiology-not arbovirus
Blastomycosis
0
(215 , 6,0,0)
Number
128
3
Leptospirosis
Listeriosis
3
31
935
Lyme disease
137
Malaria
83
119
Measles
0
Botulism
2
Meningococcal, invasive
Brucellosis
8
Murine typhus
110
46
1
Campylobacteriosis
1,294
Mumps
798
Chickenpox
1,915
Pertussis
588
Chlamydia trachomatis
Cholera
Cryptosporidiosis
53,586
1
258
Psittacosis
Q fever
Rabies, animal
Cyclospora
1
Rabies, potential human exposure
Cysticercosis
0
Reyes syndrome
Diphtheria
0
Rocky Mountain spotted fever
Ehrlichiosis, human granulocytic
6
Rubella
Ehrlichiosis, human monocytic
Ehrlichiosis, unknown type
E. coli, shiga toxin producing
Food and waterborne outbreaks
Giardiasis
Gonorrhea
H. influenzae, invasive disease
25
1
125
69 (5 recreational
water)
695
20,186
120
Salmonellosis
Shigellosis
S. aureus, vancomycin resistant
0
17
46
314
0
26
0
1,603
720
0
Streptococcus, group A, invasive
326
Streptococcus, group B, invasive
89
Streptococcus pneumoniae, invasive
Syphilis, primary or secondary
1,150
431
Hantavirus
0
Tetanus
1
Hemolytic uremic syndrome
8
Toxic shock syndrome
2
0
Hepatitis A, acute
109
Trichinosis
Hepatitis B, acute
132
Tuberculosis
Hepatitis C, acute
13
Hepatitis C, chronic or resolved
Histoplasmosis
6,843
112
234
Tularemia
569
1
Typhoid fever
18
Yersiniosis
31
Methods
Health care professionals - including infection control nurses, physicians
and school nurses - are required by Illinois law to report specific infectious
diseases to their local health department. There are 97 local health departments
in Illinois. Some serve a city or district, some serve the entire county and some
serve residents of several counties. The local health department reports cases to
the Illinois Department of Public Health, which, in turn, reports all nationally
notifiable diseases to the United States Centers for Disease Control and
Prevention (CDC). All information about patients is confidential; case reports to
the CDC do not identify patients.
This annual report includes only cases reported to the Department.
Therefore, these annual numbers will underestimate the total number of
cases of each disease in the state. Some patients with disease do not seek
medical attention, some may not have the necessary testing done for a
diagnosis, or the medical provider may not report the case to public health
authorities. Also, to standardize reporting in the state, only cases that are
reported and meet the case definition for that disease are included in case
counts. For some diseases, a case definition is listed for both confirmed and
probable cases. For all diseases except HIV/AIDS, the number of cases reported
in a year is closed out in May of the following year. If cases from the preceding
year are reported after the May date, they are not included in the preceding
year’s numbers. For HIV/AIDS, there are two categories: number of cases
reported in a given year versus number of cases diagnosed in a given year. The
number of cases diagnosed in a given year is continually updated even if there is
an extremely long delay in reporting a case. The number of cases reported for
HIV/AIDS is what is used in this report.
Reportable diseases diagnosed in college students living away from home
and in residents of prisons, long-term care or other residential facilities are
reported in the jurisdiction where the patient resides at the time of diagnosis. This
results in attributing to rural counties that have a college or prison high incidence
rates of certain diseases. Persons who are residents of Illinois but are not
citizens of the United States may be counted. Persons who are visiting the
United States and become clinically ill with malaria are counted in malaria
statistics. Residents of other states who become ill in Illinois are not counted in
this state’s statistics but are transferred to the state of residence. However,
temporary workers in Illinois are counted in Illinois statistics.
The Illinois population used to calculate incidence rates and race and
ethnicity proportions in past editions of this document was from the 2000 census
data.. The following table shows the age distribution of the Illinois population as
determined by the 2000 census.
235
Census
numbers used
for 2000
annual report
% of population
<1 year
173,373
1
1-4 years
703,176
6
5-9 years
929,858
7
10-19 years
1,799,099
14
20-29 years
1,742,602
14
30-59 years
5,108,274
41
>59 years
1,962,911
15
Age category
TOTAL
12,419,293
Where it was deemed useful, graphs were produced showing the number
of cases by month, the number of cases by year since 2001 and the age
distribution. Incidence rates were calculated by age for diseases with higher
numbers of cases. Incidence rate was calculated by taking the number of cases
in a category, dividing by population size from 2000 census data and multiplying
by 100,000. If an annual incidence rate was calculated for the period 2002 to
2006, it was reached by taking the number of cases reported from 2002 through
2006, dividing by the population and multiplying by 100,000; it was then
annualized by dividing by five.
The reports for each disease were generated from the INEDSS database.
The criteria used were year reported = 2006. For diseases where asymptomatic
cases do not meet the case definition (hepatitis A and amebiasis) these
laboratory confirmed cases were not included in the detailed information in the
disease information. The epidemiologic information presented for each disease is
for 2006 only, unless otherwise specified. For some diseases, where the number
of cases by year was low, information may have been combined for multiple
years to allow demonstration of trends by month and age. When the case
population differed from the Illinois population in the racial distribution, a chisquare test for a significant difference in proportions was done using the Epi-Info
software package.
Suggested reading lists are provided for some diseases.
236