Download 2014 Halton Region Health Department Infectious Disease Report

Halton Region Health Department
Infectious Disease Report
2014
Reference:
Halton Region Health Department, Infectious Disease Report. Oakville, Ontario, July 2015.
Author:
Joanna Oliver, Epidemiologist, Halton Region Health Department
Acknowledgements:
Carley Aubin, Epidemiologist, Halton Region Health Department
Catherine Bannan, Manager of Sexual Health/Needle Exchange Program, Halton Region Health
Department
Megan Hempel, Health Analyst, Halton Region Health Department
Kathy Jovanovic, Manager Communicable Diseases, Halton Region Health Department
Dimitra Kasimos, Manager Enteric and Vectorborne Disease, Halton Region Health Department
Jason Letchford, Data Analyst, Halton Region Health Department
Matthew Ruf, Director of Health Protection Services, Halton Region Health Department
Emma Tucker, Senior Epidemiologist, Halton Region Health Department
2014 Halton Region Infectious Disease Report
Table of Contents
2014 Halton Region Infectious Disease Report ..................................................................... 1
Presentation of the Results ................................................................................................................... 1
Part I: Leading Reportable Infectious Diseases in 2014 in Halton ........................................ 2
Comparison with Ontario Age-standardized Incidence Rates for 2014 ............................................ 5
Part II: Categories of Infectious Diseases .............................................................................. 6
Vaccine-Preventable Diseases .............................................................................................................. 6
Influenza _______________________________________________________________________ 8
Streptococcus pneumoniae ________________________________________________________ 9
Chickenpox ____________________________________________________________________ 10
Food- and Water-borne Diseases........................................................................................................ 13
Campylobacter enteritis __________________________________________________________ 14
Giardiasis _____________________________________________________________________ 15
Salmonellosis __________________________________________________________________ 16
Sexually-Transmitted Infections ......................................................................................................... 17
Chlamydia_____________________________________________________________________ 18
Gonorrhoea ___________________________________________________________________ 20
Syphilis _______________________________________________________________________ 21
Select Blood-borne Infections ............................................................................................................. 23
Hepatitis C ____________________________________________________________________ 24
Hepatitis B ____________________________________________________________________ 25
Select Bacterial Diseases Transmitted by Direct Personal Contact or Respiratory Routes ........ 27
Tuberculosis ___________________________________________________________________ 28
Group A Streptococcal Infections ___________________________________________________ 30
Diseases Transmitted by Insects and Animals ................................................................................. 31
Other Reportable Infectious Diseases ................................................................................................ 32
Encephalitis and Meningitis _______________________________________________________ 33
Part III: Hospital Utilization .....................................................................................................34
Infectious Diseases – Emergency Department Visits ....................................................................... 34
Infectious Diseases – Hospitalizations .............................................................................................. 36
Part IV: Outbreak Investigations ............................................................................................38
Outbreaks by Location ......................................................................................................................... 39
Respiratory Outbreaks ......................................................................................................................... 41
Enteric Outbreaks ................................................................................................................................. 42
Outbreak Trends ................................................................................................................................... 43
Number of Cases Investigated ............................................................................................................ 45
Appendix A: O. Reg 559/91 under the Health Protection and Promotion Act .....................46
Appendix B: The Number of Reported Cases of Communicable Disease in 2014
compared to 2013 and the previous 5-year average (2009–2013), and the AgeStandardized Rates per 100,000 Population, Halton residents. ...........................................48
Appendix C: Summary of rare reportable infectious diseases and those with low
incidence, Halton residents, 2000–2014. ...............................................................................50
2014 Halton Region Infectious Disease Report
List of Figures
Figure 1:
Figure 2:
Figure 3:
Figure 4:
Figure 5:
Figure 6:
Figure 7:
Figure 8:
Figure 9:
Figure 10:
Figure 11:
Figure 12:
Figure 13:
Figure 14:
Figure 15:
Figure 16:
Figure 17:
Figure 18:
Figure 19:
Figure 20:
Figure 21:
Figure 22:
Figure 23:
The 10 most frequently reported infectious diseases compared to previous five-year
annual average, Halton residents, 2014. ................................................................. 4
Most frequently reported vaccine-preventable diseases compared to previous fiveyear annual average, Halton residents, 2014. ......................................................... 7
Influenza, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014............................................................. 8
Invasive Streptococcus pneumoniae, age-standardized incidence rates per 100,000
population, Halton residents 2005–2014. ................................................................ 9
Chickenpox (varicella), total number of ED visits in Halton and age-standardized
rates of emergency department visits, Halton residents compared to Ontario, 20042014. ......................................................................................................................11
Proportion of emergency department visits attributed to chickenpox, by age group,
Halton and Ontario, 2014. ......................................................................................12
Most frequently reported food- and water-borne diseases compared to previous
five-year annual average, Halton residents, 2014. ..................................................13
Campylobacter enteritis, age-standardized incidence rates per 100,000 population,
Halton residents compared to Ontario, 2005–2014. ...............................................14
Giardiasis, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014............................................................15
Salmonellosis, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014............................................................16
Sexually-transmitted infections compared to previous five-year annual average,
Halton residents, 2014. ..........................................................................................17
Chlamydia, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014............................................................19
Gonorrhea, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario 2005–2014.............................................................20
Number of cases of syphilis compared to previous five-year annual average, Halton
residents, 2014.......................................................................................................21
Infectious and non-infectious syphilis, age-standardized incidence rates per 100,000
population, Halton residents compared to Ontario, 2004–2014. .............................22
The number of selected blood-borne infections compared to previous five-year
annual average, Halton residents, 2014. ................................................................23
Hepatitis C, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014............................................................24
Hepatitis B infection, age-standardized incidence rates per 100,000 population,
Halton residents compared to Ontario, 2004–2014. ...............................................26
Number of cases of selected bacterial diseases spread by close contact or
respiratory routes compared to previous five-year annual average, Halton residents,
2014. ......................................................................................................................27
Number of cases of tuberculosis compared to the previous five-year annual
average, Halton residents, 2014. ............................................................................28
Tuberculosis (infectious only), age-standardized incidence rate per 100,000
population, Halton residents compared to Ontario, 2005–2014. .............................29
Severe group A streptococcal infections, age-standardized incidence rates per
100,000 population, Halton residents compared to Ontario, 2005–2014.................30
Number of cases of diseases spread by arthropods compared to previous five-year
annual average, Halton residents, 2014. ................................................................31
2014 Halton Region Infectious Disease Report
Figure 24: Number of cases of meningitis and enchephalitis compared to previous five-year
annual average, Halton residents, 2014. ................................................................32
Figure 25: Encephalitis and Meningitis combined, age-standardized incidence rates per
100,000 population, Halton residents compared to Ontario, 2005–2014.................33
Figure 26: Emergency department visits attributed to infectious diseases, number of visits and
age-standardized rates per 100,000 population, Halton residents, 2010-2014. ......34
Figure 27: Emergency department visits attributed to infectious diseases, age-specific rates,
Halton residents, 2010-2014 combined. .................................................................35
Figure 28: Emergency department visits attributed to infectious diseases, age-standardized
rates, by neighbourhood income group, Halton residents, 2010-2014 combined. ..35
Figure 29: Hospitalizations attributed to infectious diseases, number of visits and agestandardized rates per 100,000 population, Halton residents, 2010-2014. .............36
Figure 30: Hospitalizations attributed to infectious diseases, age-specific rates, Halton
residents, 2010-2014 combined. ............................................................................36
Figure 31: Hospitalizations attributed to infectious diseases, age-standardized rates, by
neighbourhood income group, Halton residents, 2010-2014 combined. ................37
Figure 32: Type of outbreak by municipality, Halton Region, 2014. .........................................39
Figure 33: Outbreaks by type of location, Halton Region, 2014. ..............................................40
Figure 34: Proportion of respiratory outbreaks by causative agent (laboratory-confirmed or
suspected), Halton Region, 2014. ..........................................................................41
Figure 35: Proportion of enteric outbreaks by causative agent (laboratory-confirmed or
suspected), Halton Region, 2014. ..........................................................................42
Figure 36: Number of outbreaks by type and month of onset, Halton Region, 2014. ...............43
Figure 37: Number of outbreaks by type and duration, Halton Region, 2014. ..........................44
2014 Halton Region Infectious Disease Report
List of Tables
Table 1: Number, crude incidence rates, and age-standardized incidence rates of the top ten
most frequently reported infectious diseases in Halton in 2014 compared to reports for
same diseases in the previous two years. .................................................................. 3
Table 2: Age-standardized incidence rates per 100,000 population for the top ten most
frequently reported infectious diseases, Halton and Ontario, 2014. ............................ 5
Table 3: Number of outbreaks, by type of outbreak and location, Halton Region, 2014...........40
Table 4: Number of outbreaks by location, Halton Region, 2009–2014. ..................................44
Table 5: Total number of clients and staff who were at risk and who were ill, by location of the
outbreak, respiratory and enteric outbreaks combined, Halton Region, 2014. ...........45
2014 Halton Region Infectious Disease Report
2014 Halton Region Infectious Disease Report
The 2014 Halton Region Infectious Disease Report summarizes the incidence of infectious
(communicable) diseases that were reported to the Health Department for Halton Region
residents in 2014. These diseases are caused by a variety of organisms including bacteria,
viruses, and protozoa, or by toxins from these organisms. Infectious diseases are spread from
one host to another by close personal contact, sexual contact, contaminated food or water,
animals, or other environmental sources. The current list of infectious diseases that must be
reported to the local medical officer of health under the Health Protection and Promotion Act
(HPPA) are shown in Appendix A. Outbreaks of any infectious diseases must also be reported.
The 2014 Halton Region Infectious Disease Report reflects the surveillance and health status
reporting function that the Health Department is mandated to perform in order to monitor the
impact of infectious disease programs and to identify significant or emerging issues.
The Health Department works towards the goal of reducing the incidence of infectious diseases
in the community through the delivery of various programs. Staff members investigate reports of
individual cases and respond to outbreaks in both the community and in institutions such as
long-term care homes, acute care settings, child care settings, schools, colleges, and
correctional institutions. In addition to investigating disease reports and preventing further
spread of disease, the Health Department also conducts inspections of licensed child care
settings, personal services settings, food premises, small drinking water systems, and public
spas and swimming pools. Finally, the Health Department is mandated to provide education and
certification programs, such as food handler training, as well as clinical services, such as
immunization and sexual health clinics, which help to prevent and reduce the burden of
infectious diseases.
Presentation of the Results
Part I of this report provides an analysis of the 10 most frequently reported infectious diseases
among Halton residents, along with comparisons to the last two years of data (2012 and 2013),
the previous five-year annual average, and the ten-year trend, as well as comparisons to
Ontario overall. Part II of the report summarizes all cases of reportable infectious diseases,
grouping these into categories based on major immunization strategies (e.g., vaccinepreventable diseases) and main modes of transmission. Part III of the report summarizes
hospital utilization attributed to infectious diseases. Part IV of the report presents an analysis of
all the outbreaks that were investigated by the Halton Region Health Department during 2014.
Appendix B presents a complete list of the reported cases of infectious disease in 2014 and the
corresponding age-standardized incidence rates for 2014 and 2013. Significant changes in rates
from 2013 are indicated by up or down arrows. Appendix C presents a summary of rare
reportable infectious diseases with low incidence or no reported cases in 2014.
2014 Halton Region Infectious Disease Report
1
Part I: Leading Reportable Infectious Diseases in 2014 in
Halton
In 2014, 2,061 cases of reportable infectious diseases were reported to the Halton Region
Health Department for investigation (Table 1). Table 1 shows the 10 most frequently reported
infectious diseases that accounted for 89% of the total cases. Figure 1 shows the number of
cases of these diseases in 2014 compared to the previous five-year annual average. In 2013
and 2012 there were 1,779 and 1,789 cases of reported infectious diseases, respectively.
Please note that this report is based on reports of infectious diseases for the calendar year
2014, but that influenza numbers are reported for the influenza season which begins in
September of the previous year (2013) and ends in August of the current calendar year on
which this report is based (2014).
2014 Halton Region Infectious Disease Report
2
Table 1: Number, crude incidence rates, and age-standardized incidence rates of the top ten most frequently reported infectious
diseases in Halton residents, 2014 compared to reports for same diseases in the previous two years.
2014
Disease
Chlamydia
2
Influenza
Gonorrhea
Campylobacter enteritis
Salmonellosis
Hepatitis C
Giardiasis
Streptococcus
pneumoniae - invasive
Encephalitis and
3
meningitis
Streptococcal infections,
group A
Total Number of
Reported Confirmed
Cases –Top 10 in each
year
All Other Reported Cases
TOTAL NUMBER OF
REPORTED
CASES
2013
Total
Reported
Confirmed
Cases
Crude
Incidence
Rate per
100,000
Standardized
Incidence
Rate per
100,000
822
149.9
379
129
128
118
102
46
1
2012
Total
Reported
Confirmed
Cases
Crude
Incidence
Rate per
100,000
Standardized
Incidence
Rate per
100,000
180.7
747
138.5
69.1
23.5
23.3
21.5
18.6
8.4
67.2
28.9
22.9
22.4
18.9
8.2
292
63
138
91
96
43
41
7.5
6.3
36
6.6
23
1,824
1
Total
Reported
Confirmed
Cases
Crude
Incidence
Rate per
100,000
Standardized
Incidence
Rate per
100,000
171.3
764
144.7
180.0
54.1
11.7
25.6
16.9
17.8
8.0
50.3
14.5
26.6
17.5
18.0
8.6
182
68
157
107
96
50
34.4
13.2
29.7
20.2
18.2
9.5
35.8
15.6
29.8
21.9
18.3
9.4
25
4.6
4.2
37
7.0
5.9
6.7
43
8.0
7.7
34
6.4
6.8
4.2
4.2
18
3.3
3.1
17
3.2
3.2
332.5
365.3
1,556
288.3
321.7
1,512
285.8
326.7
237
223
269
2,061
1,779
1,781
st
st
Notes: 1. Rates were age-standardized to the 1991 Canadian Population. 2. Influenza numbers are provided for the Influenza Season of Sept. 1 to Dec. 31 of
st
st
the previous year and Jan. 1 to Aug. 31 of the current year. 3. This excludes bacterial meningitis.
Source: Integrated Public Health Information System [2012-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ontario Ministry of Health and
Long-Term Care [2013], extracted March 21, 2015.
2013 Halton Region Infectious Disease Report
3
1
Figure 1 shows the same 10 most frequently reported infectious diseases. The numbers of
cases for 2014 are compared to the average number of cases per year in the previous five
years, 2009 to 2013.
822
772
Chlamydia
379
Influenza
284
129
Disease
Gonorrhea
66
128
135
118
100
102
96
Campylobacter enteritis
Salmonellosis
Hepatitis C
Giardiasis
46
51
Streptococcus pneumoniae - invasive
41
36
36
32
Encephalitis and meningitis*
23
14
Streptococcal infections, Group A
0
100
200
300
400
500
600
700
800
900
Number of reported cases
2014
2009-2013 annual average
Figure 1: The 10 most frequently reported infectious diseases compared to previous five-year
annual average, Halton residents, 2014.
st
st
Notes: Influenza numbers are provided for the Influenza Season of Sept. 1 to Dec. 31 of the previous year and Jan.
st
st
1 to Aug. 31 of the current report year. (*) This excludes bacterial meningitis.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
Of the ten most frequently reported infectious diseases among Halton residents in 2014,
chlamydia and gonorrhea are sexually transmitted infections; influenza and Streptococcus
pneumoniae are respiratory infections; campylobacter enteritis, salmonellosis and giardiasis are
food and water-borne diseases; hepatitis C is a blood-borne infection; and group A
streptococcal infection and encephalitis/meningitis is transferred by close contact. Influenza and
Streptococcus pneumonia, and certain subtypes of meningitis, are vaccine preventable
diseases. The full list of reportable infectious diseases for Ontario in 2014 is provided in
Appendix A.
Appendix B presents a complete list of the reported cases of infectious disease in 2014 and the
corresponding age-standardized incidence rates for the current and previous year (2013).
2014 Halton Region Infectious Disease Report
4
Comparison with Ontario Age-standardized Incidence Rates for 2014
In 2014 there were some differences between the age-standardized incidence rates of the 10
most frequently reported infectious diseases in Halton as compared to Ontario (Table 2). The
standardized incidence rates of chlamydia, gonorrhea, and hepatitis C were statistically
significantly lower in Halton residents compared to Ontario. There were no statistically
significant differences, between Halton and Ontario in the incidence of influenza, campylobacter
enteritis, salmonellosis, giardiasis, Streptococcus pneumoniae, or group A streptococcal
infections. The standardized incidence rate of encephalitis and meningitis was statistically
significantly higher for Halton residents compared to Ontario. Halton had 36 cases of
encephalitis and meningitis reported in 2014, which is similar to the number of cases reported
annually since 2010, and the cases appear to be unrelated. Appendix B presents a complete list
of the reported cases of infectious disease in 2014 and the corresponding age-standardized
incidence rates for Halton.
Table 2: Age-standardized incidence rates per 100,000 population for the top ten most
frequently reported infectious diseases, Halton and Ontario, 2014.
Disease
Chlamydia
1
Influenza
Gonorrhea
Campylobacter
enteritis
Salmonellosis
Hepatitis C
Giardiasis
Streptococcus
pneumoniae invasive
Encephalitis and
3
meningitis
Streptococcal
infections,
group A
HALTON
2014
Age-standardized
incidence rate per
100,000
(95% CI)
ONTARIO
2014
Age-standardized
incidence rate per
100,000
(95% CI)
Agestandardized
Incidence Ratio
(95% CI)
Halton
compared
to Ontario2
180.7 (168.2-193.3)
67.2 (60.2-74.2)
27.8 (22.9-32.8)
299.0 (295.9-302.1)
68.8 (67.4-70.2)
48.1 (46.9-49.4)
0.60 (0.56-0.64)
0.97 (0.87-1.1)
0.58 (0.48-0.68)
↓
↔
↓
22.9 (18.8-27.0)
27.3 (26.4-28.2)
0.86 (0.71-1.0)
↔
22.4 (18.2-26.5)
18.9 (15.1-22.8)
8.2 (5.8-10.7)
23.8 (22.9-24.7)
29.7 (28.8-30.6)
9.7 (9.2-10.2)
0.94 (0.77-1.10)
0.63 (0.51-0.75)
0.90 (0.64-1.16)
↔
↓
↔
6.2 (4.2-8.1)
6.4 (6.0-6.8)
1.0 (0.70-1.31)
↔
6.7 (4.5-9.0)
4.3 (3.9-4.6)
1.6 (1.1-2.1)
↑
4.2 (2.4-5.9)
4.8 (4.7-5.2)
0.81 (0.48-1.15)
↔
Notes: (1) Influenza data for Ontario is for the season 2013-2014 (calculated as of Sept. 1st to Dec. 31st of previous year and Jan.
1st to Aug. 31st of the year of reporting). (2) Comparison between Halton residents and Ontario: (↔) indicates that there was no
statistically significant difference between Halton and Ontario; (↓) indicates that the age-standardized incidence rate in Halton was
significantly lower than Ontario; and, (↑) indicates that the age-standardized incidence rate in Halton was significantly higher than
Ontario. If the confidence interval (CI) range for the age-standardized Incidence Ratio contains one, the differences were not
statistically significant between Halton and Ontario; if the CI range was below one Halton has a statistically significantly lower rate
than Ontario; and if the CI range was above 1 Halton has a statistically significantly higher rate than Ontario. (3) This excludes
bacterial meningitis.
Sources: Integrated Public Health Information System [2015], extracted March 23, 2015; Population Estimates, IntelliHealth, Ontario
Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term
Care, Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
5
Part II: Categories of Infectious Diseases
The data in this section of the report are presented under the following six categories:
1. Vaccine Preventable Diseases
2. Food- and Water-borne Diseases
3. Sexually-transmitted Infections
4. Blood-borne Infections
5. Diseases Transmitted by Direct Personal Contact and Respiratory Routes
6. Diseases Transmitted by Insects and Animals
The numbers of reported cases for Halton residents are shown, along with comparisons to the
previous five-year annual average. Age-standardized incidence rates are also included allowing
for comparison to the province and other health regions.
Vaccine-Preventable Diseases
Immunization has played a key role in reducing the burden of many diseases and has even
eradicated (i.e., world-wide) or eliminated (e.g., continent-wide) some diseases that in the past
century have caused major illness and loss of life. Illnesses from nine infectious diseases (i.e.,
smallpox, diphtheria, pertussis, tetanus, polio, measles, mumps, rubella, and H. influenzae type
b) have decreased substantially or been eliminated entirely in North America.
Ontario children under the age of six now receive immunization against 12 diseases. Some
vaccines require only a single dose, some require multiple doses over a period of years; some
are available combined, others must be given separately. Because vaccines have different
levels of effectiveness and/or do not cover all strains/sub-types of the organisms at which they
are aimed, not all vaccines are equally effective. Also, coverage of the population is not 100%.
This is why it is important to monitor the incidence of vaccine-preventable diseases.
In 2014, 450 Halton residents were diagnosed with vaccine-preventable diseases, accounting
for 22% of the total cases of reportable infectious diseases that year (Appendix B). Figure 2
shows the number of cases of vaccine-preventable diseases in Halton residents in 2014
compared to the previous five-year annual averages.
2014 Halton Region Infectious Disease Report
6
Number of reported cases
400
300
200
379
279
100
41
0
Influenza
36
Streptococcus
pneumoniae invasive
14
8
Pertussis
1
1
0
Measles
3
Mumps
Disease
2014
2009-2013 Annual Average
Figure 2: Most frequently reported vaccine-preventable diseases compared to previous fiveyear annual average, Halton residents, 2014.
st
st
Note: Influenza numbers are provided for the Influenza Season of Sept. 1 to Dec. 31 of the previous year and Jan.
st
st
1 to Aug. 31 of the current report year.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
7
Influenza
Of the 450 cases of potentially vaccine-preventable disease, 379 were residents of Halton
diagnosed with influenza (during the Sept. 1, 2013 to Aug. 31, 2014 influenza season).
Influenza is a highly infectious respiratory illness caused by one of the three types of influenza
virus: A, B, or C (C is not common nor an important cause of illness, does not have a vaccine,
and is not tested for by the laboratory). In contrast to the common cold, symptoms of influenza
are more sudden in onset and more severe (fever, headache, muscle ache, and profound
tiredness, followed by the onset of a dry cough), especially in very young, old, or immunecompromised persons. Many cases of influenza are not diagnosed or reported to the Halton
Region Health Department because infected individuals often do not seek medical attention or,
when doctors are visited, physicians often do not seek laboratory confirmation because it is
unnecessary in uncomplicated situations when influenza is known to be circulating. Monitoring
influenza is important due to how quickly epidemics evolve, the widespread morbidity, and the
seriousness of complications, notably viral and bacterial pneumonias.
Halton age-standardized influenza incidence rates have been similar to those of the province
(Figure 3). The impact of influenza as well as the rate of clinical testing are highly variable and
therefore annual fluctuations above or below the provincial average are not surprising. The
number of laboratory-confirmed cases of influenza can be helpful for tracking the timing and
severity of the influenza season. However the actual numbers are always an underestimate
because a large proportion of infected persons would not receive laboratory testing.
Age-standardized incidence rate
(per 100,000)
100
80
60
40
20
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 3: Influenza, age-standardized incidence rates per 100,000 population, Halton residents
compared to Ontario, 2005–2014.
st
st
Notes: Influenza numbers are provided for the Influenza Season of Sept. 1 to Dec. 31 of the previous year and Jan.
st
st
1 to Aug. 31 of the current report year.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ontario Ministry of
Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and LongTerm Care, Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
8
Streptococcus pneumoniae
In 2014, there were 41 reported cases of invasive Streptococcus pneumoniae, accounting for
9% of the reportable vaccine-preventable diseases.
Pneumococcal disease is a major cause of pneumonia (not reportable) and meningitis
(reportable) among children and the elderly.
As seen in Figure 4, the age-standardized incidence rates of Streptococcus pneumoniae in
Halton were quite variable in the past five years of reporting, as would be expected because of
the relatively small numbers. In 2014, the Halton age-standardized incidence rate for this
infectious disease (6.2 per 100,000 population) was not statistically significantly different from
the provincial rate (6.4 per 100,000 population) (Table 2).
Age-standardized incidence rate
(per 100,000)
10
8
6
4
2
0
2005
2006
2007
2008
2009
Halton
2010
2011
2012
2013
2014
Ontario
Figure 4: Invasive Streptococcus pneumoniae, age-standardized incidence rates per 100,000
population, Halton residents 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
9
Chickenpox
Chickenpox, or varicella, is an acute, generalized viral disease with sudden onset of slight fever,
mild constitutional symptoms, and a skin eruption that is maculopapular for a few hours,
followed by small blisters for 3 to 4 days, and then granular scab that may leave small scars.
Chickenpox is transmitted person-to-person by direct contact, droplet, or airborne spread of
vesicle fluid or secretions of the respiratory tract. It is one of the most readily communicable of
diseases, especially in the early stages. Susceptible individuals have an 80% to 90% risk of
infection after household exposure. This viral infection remains latent and the disease may recur
years later as herpes zoster in about 15% of older adults, and sometimes in children.
The one-dose varicella immunization program was introduced in Ontario in 2004 and was added
to the children’s immunization schedule. The program was expanded in August 2011 to include
a second dose to reduce breakthrough infections from waning immunity in individuals who
previously received a single dose.
As of January 2005, the first year for which case-specific data was available, individual
laboratory-confirmed reports or those cases resulting in complications or hospitalization were
reportable to the Health Department. However, cases that ran their course of illness at home
may not have been reported to the Halton Region Health Department. Also, physicians may
make a clinical diagnosis of the disease and may not report it to the health department.
Therefore caution must be taken when interpreting local and provincial data as it is subject to
significant underreporting.
In 2014, in Halton residents, there were 15 lab-confirmed cases of chickenpox. Six (40%) of
these cases occurred in children aged 0 to 14 and five (33%) in adults aged 40 to 49.
Since lab-confirmed cases are so underreported, cases of varicella presenting to emergency
departments between 2004 and 2014 were examined. This allows for an analysis of the trends
as well as comparison between Halton and Ontario.
2014 Halton Region Infectious Disease Report
10
Chickenpox – Emergency Department visits
In Halton residents, between 2004 and 2014, the number of emergency department (ED) visits
due to chickenpox declined by 64% from 129 visits in 2004 to 47 visits in 2014.
The biggest decline in the number of ED visits occurred between 2004 and 2005 when the
number of visits in Halton went from 129 to 89 (Figure 5). This may in part by explained by the
introduction of the chickenpox vaccine in 2004.
140
140
120
120
100
100
80
80
60
60
40
40
20
20
0
0
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
Age-standardized rate (per 100,000)
Number of ED visits
In Halton, the age-standardized rate of emergency department visits attributed to chickenpox
declined significantly from 33.7 per 100,000 in 2004 to 9.7 per 100,000 in 2014 (Figure 5).
2014
Year
Halton ED visits
Halton age-std rate per 100,000
Ontario age-std rate per 100,000
Figure 5: Chickenpox (varicella), total number of ED visits in Halton and age-standardized rates
of emergency department visits, Halton residents compared to Ontario, 2004-2014.
Notes: Varicella emergency department visits may be used as a proxy to indicate the severity of the disease.
Sources: National Ambulatory Care Reporting Centre, Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario, extracted [May 1, 2015]. Population Estimates, Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario, extracted [March 21, 2014].
In Ontario overall, the total number of ED visits due to chickenpox declined by 62% from 6,200
in 2004 to 2,342 in 2014 (not shown). The age-standardized rate of ED visits due to chicken
pox in Ontario, during this time period, declined significantly from 58.7 per 100,000 population to
20.5 per 100,000 population (Figure 5).
In 2014, Halton’s age-standardized rate of emergency department visits attributed to chickenpox
was statistically significantly lower compared to Ontario’s (SIR=0.47 [95% CI: 0.34-0.60]).
In 2014, children aged 0 to 9 accounted for 60% of the total emergency department visits
attributed to chickenpox in Halton and 55% in Ontario overall (Figure 6).
2014 Halton Region Infectious Disease Report
11
50
% of ED visits
40
30
20
40
38
21
10
17
16
16
15
17
9
12
0
0-4
5-9
10-19
20-44
45+
Age Group
Halton
Ontario
Figure 6: Proportion of emergency department visits attributed to chickenpox, by age group,
Halton and Ontario, 2014.
Sources: National Ambulatory Care Reporting Centre, Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario, extracted [May 1, 2015]. Population Estimates, Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario, extracted [March 21, 2014].
2014 Halton Region Infectious Disease Report
12
Food- and Water-borne Diseases
Infectious diseases spread by food and water are caused by bacteria, parasites, and viruses
that have found their way into the water supply or food source from an infected animal or
person. Because the route of exposure to food- and water-borne diseases is by ingestion and
because the symptoms are usually related to the digestive tract, these diseases are often also
referred to as enteric diseases, meaning relating to the intestine. Many of these diseases are
sometimes also transmitted from person to person, even when there is careful attention paid to
personal hygiene. These diseases may cause nausea, vomiting, abdominal pain, diarrhoea,
bloody stools, fever, and systemic illness that can be severe. Illness caused by toxins (e.g., from
Staphylococcus aureus) or other toxic agents can also be spread by food and water.
In 2014, 377 Halton residents were diagnosed with a food- or water-borne disease, accounting
for 18% of the total cases of reportable infectious diseases that year (Appendix B). Figure 7
shows the number of new cases of food- and water-borne diseases among Halton residents in
2014 compared to the previous five-year annual average.
Number of reported cases
150
125
100
75
128 135
50
118
100
25
46
51
18
18
0
13
5
8
11
Disease
2014
2009-2013 Annual Average
Figure 7: Most frequently reported food- and water-borne diseases compared to previous fiveyear annual average, Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
In addition to the diseases highlighted in Figure 7, there were also a total of 43 cases of the
following diseases, accounting for the remaining 11% of this disease category: hepatitis A,
legionellosis, listeriosis, paratyphoid fever, shigellosis, typhoid fever, verotoxin-producing
Escherichia coli, and yersiniosis. For these, the numbers have remained fairly stable when
compared to the previous five-year average. Please refer to Appendix B for the number of
reported cases in 2014 for these remaining diseases.
2014 Halton Region Infectious Disease Report
13
Campylobacter enteritis
Of the 377 cases of reported food- and water-borne infectious disease in Halton in 2014, 128
(34%) were diagnosed with Campylobacter enteritis. There were 135 cases of Campylobacter
enteritis reported on average per year in the previous five years (Figure 7).
Animals—most frequently poultry and cattle—are the reservoirs of the causative organisms. The
most common mode of transmission of this disease is through ingestion of the organisms in
undercooked meat, contaminated food or water, or unpasteurized milk. Over the past 10 years,
the age-standardized incidence rates in Halton followed similar incidence rates as Ontario
(Figure 8).
In 2014, the Halton age-standardized incidence rate of campylobacteriosis (22.9 per 100,000
population) was similar to the Ontario age-standardized incidence rate (27.3 per 100,000
population) (Table 2).
Age-standardized incidence rate
(per 100,000)
40
30
20
10
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 8: Campylobacter enteritis, age-standardized incidence rates per 100,000 population,
Halton residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
14
Giardiasis
Giardiasis accounted for 12% of the food- and water-borne infections (46 cases) reported in
Halton in 2014. There were 51 cases of giardiasis reported on average per year in the previous
five years (Figure 7).
Giardiasis is a protozoan infection principally of the upper small intestine, which can a) remain
asymptomatic; b) bring on acute, self-limited diarrhoea; or c) lead to intestinal symptoms such
as chronic diarrhoea, abdominal cramps, bloating, frequent loose, pale, greasy stools, fatigue,
malabsorption (of fats and fat-soluble vitamins), and weight loss. The reservoirs are humans,
and possibly beaver and other wild and domestic animals. Person-to-person transmission
occurs by hand-to-mouth transfer of cysts from the faeces of an infected individual, especially in
institutions and day care centres; this is probably the principal mode of spread. The incubation
period is usually between 3 and 25 days, with a median of 7 to 10 days. The period of
communicability is during the entire period of infection, and often for months afterwards.
In the past 10-year period, Halton’s age-standardized rates of giardiasis have been similar to or
lower than Ontario’s rates (Figure 9). In 2014, Halton’s age-standardized rate of 8.2 cases per
100,000 population was similar to Ontario’s age-standardized rate of 9.7 cases per 100,000
population (Table 2).
Age-standardized incidence rate
(per 100,000)
15
10
5
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 9: Giardiasis, age-standardized incidence rates per 100,000 population, Halton residents
compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
15
Salmonellosis
Salmonellosis accounted for 31% of the food- and water-borne infections (118 cases) reported
in Halton in 2014. There were 100 cases of salmonellosis reported on average per year in the
previous five years (Figure 7).
Salmonellosis is classified as a food-borne disease because contaminated food, mainly of
animal origin, is the predominant mode of transmission.
Over the past 10 years, the age-standardized incidence rates of salmonellosis in Halton
fluctuated along with the Ontario rates (Figure 10). The high rate in Halton in 2005 is attributed
to a single outbreak in a food premises. In 2014, the age-standardized incidence rate in Halton
of 22.4 cases per 100,000 population was similar to the provincial rate (23.8 per 100,000
population) (Table 2).
Age-standardized incidence rate
(per 100,000)
40
30
20
10
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 10: Salmonellosis, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
16
Sexually-Transmitted Infections
In 2014, 1,006 Halton residents were diagnosed with a sexually-transmitted infection,
accounting for 49% of the total cases of reportable infectious diseases (Appendix B). Figure 11
shows the number of new cases of sexually-transmitted infection among Halton residents in
2014 compared to the previous five-year annual average.
Number of reported cases
1000
800
600
400
822
772
200
129
0
Chlamydia
66
Gonorrhea
29
32
13
Syphilis - noninfectious
11
HIV
10
10
Syphilis infectious
2
2
AIDS
Disease
2014
2009-2013 Annual Average
Figure 11: Sexually-transmitted infections compared to previous five-year annual average,
Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
17
Chlamydia
Of the 1,006 cases of reported sexually-transmitted infections in Halton in 2014, 822 were
diagnosed with chlamydia. These cases accounted for 82% of all the sexually-transmitted
infections for Halton residents. There were 772 reported cases on average per year in the
previous five years (Figure 11).
Chlamydia is the most common bacterial sexually-transmitted infection. It manifests in men
primarily as urethritis, and in females as cervical infection. However, up to 70% of sexually
active females with chlamydia infections are asymptomatic. Complications of chlamydial
infection include infertility and congenital infection. Asymptomatic infections can also be found in
up to 25% of sexually active men. Therefore, this disease is likely to be under-reported.
The age-standardized incidence rates of chlamydial infections in Halton showed a rising trend
between 2004 and 2010 (Figure 12). These rates followed the general upward trend
experienced in Ontario overall, with Halton’s age-standardized incidence rates remaining
significantly below the provincial rates. The increasing incidence of chlamydia has also been
noted for Canada as well as Ontario.
In Halton, the standardized incidence rate increased 62% between 2005 and 2014, from 111.5
per 100,000 to 180.7 per 100,000 residents. Some of this increase is attributed to improved
quality and acceptability of screening and testing methods. However, chlamydia is a hidden
epidemic due to lack of awareness of the problem and because the majority of cases are
asymptomatic but still infectious. Awareness-raising initiatives continue to be critical
components of promotional strategies targeting the importance of safer sex practices—
especially the use of condoms—and testing for sexually transmitted infections. Persons who
became infected with chlamydia showed they were at risk for becoming infected with
gonorrhoea, syphilis, or HIV, had any one of these sexually transmitted infections also been
present in the sexual partner. Rising trends are reported for other sexually transmitted
infections.
Similar to Ontario, the majority of cases in Halton were in youth and young adults. More
specifically, 56% of cases were in those aged 15 to 24 years, and 39% were in those aged 25 to
44 years.
2014 Halton Region Infectious Disease Report
18
Age-standardized incidence rate
(per 100,000)
350
300
250
200
150
100
50
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 12: Chlamydia, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
19
Gonorrhoea
In 2014, there were 129 cases of reported gonorrhoea infections in Halton, accounting for 13%
of all sexually-transmitted infections. There were 66 reported cases on average per year in the
previous five years (Figure 11). The age-standardized incidence rate of gonorrhea had been
relatively stable between 2006 and 2013; however, both Halton and Ontario saw an increase in
2014 (Figure 13), although, Halton’s gonorrhea rates continue to be consistently lower than
Ontario.
Public Health Ontario has been monitoring this increase provincially and has reported that “it is
not fully understood and likely multifactorial” (PHO Monthly Infectious Disease Report, February
2015). In particular they are examining antibiotic sensitivity, adherence to treatment and testing
guidelines, and have undertaken an evaluation of Ontario’s provincial treatment guidelines.
Gonorrhoea, or gonococcal infection, is a sexually-transmitted bacterial infection, which differs
in males and females in course, severity, and ease of recognition. Worldwide, this infection
affects both men and women, especially sexually active adolescents and younger adults.
Untreated individuals may be infectious for months.
As seen in Ontario, the majority of cases in Halton were in youth and young adults. More
specifically, 33% of cases were in those aged 15 to 24 years, and 52% were aged 25 to 44
years.
Age-standardized incidence rate
(per 100,000)
60
50
40
30
20
10
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 13: Gonorrhea, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
20
Syphilis
In 2014, there were 39 reported cases of syphilis (10 infectious and 29 non-infectious) in Halton
residents, accounting for 4% of all sexually-transmitted infections. There were 41 reported
cases on average per year in the previous five years (Figure 14).
Syphilis is a complex, sexually-transmitted bacterial infection characterized clinically by a
primary lesion—a chancre (painless ulcer), secondary eruptions involving skin and mucous
membranes that are very infectious, long periods of latency, and later involvement of skin, bone,
viscera, the central nervous system, and cardiovascular system. All untreated cases will go on
to a latent period of weeks to years, and one-third will then exhibit tertiary syphilis signs and
symptoms. In the early years of latency, there may be recurrence of infectious lesions of the
skin and mucous membranes. Syphilis is infectious mostly during the acute phases, and is noninfectious during most of the latent period. Fetal infection results in congenital syphilis and
occurs with high frequency in untreated early infections of pregnant women.
Figure 14 shows the number of reported cases of syphilis, by type, among Halton residents in
2014 compared to the previous five-year annual averages.
Number of reported cases
50
40
30
20
39
41
29
31
10
10
10
0
Syphilis - total
Syphilis - infectious
Syphilis - non-infectious
Disease
2014
2009-2013 Annual Average
Figure 14: Number of cases of syphilis compared to previous five-year annual average, Halton
residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
21
Halton’s age-standardized incidence rates of infectious syphilis fluctuated but showed a general
increase over the 10-year period (Figure 15). The 2014 age-standardized incidence rate was
2.0 cases per 100,000. These fluctuations are due to the small number of reported cases on a
year-to-year basis. In Ontario, infectious syphilis has been increasing from a rate of 2.9 cases
per 100,000 population in 2005 to a rate of 6.3 cases per 100,000 in 2014 (Figure 15).
Between 2005 and 2014, the age-standardized incidence rate of non-infectious syphilis in
Ontario was on average 6.9 cases per 100,000 population.
Age-standardized incidence rate
(per 100,000)
Newly diagnosed non-infectious syphilis cases are found primarily through screening and the
higher rates of non-infectious disease may reflect increased screening. While cases of noninfectious syphilis may have actually been acquired years before they are diagnosed and
reported, they are still counted as incident cases in the year of diagnosis.
14
12
10
8
6
4
2
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton Syphilis - Infectious
Halton Syphilis - Non-infectious
Ontario Syphilis - Infectious
Ontario Syphilis - Non-infectious
Figure 15: Infectious and non-infectious syphilis, age-standardized incidence rates per 100,000
population, Halton residents compared to Ontario, 2004–2014.
Note: Ontario data for non-infectious syphilis prior to 2005 is not available.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
22
Select Blood-borne Infections
Blood-borne infections are those which can be transmitted by direct contact with blood or bodyfluids, or by organ transplants involving infected organs, and also include some diseases which
are transmitted by unprotected sex or injection drug use. In the past these infections were also
spread by blood transfusions; now blood donor screening prevents almost all such cases in
which the agent is known and for which a test is available and being used.
All reportable blood-borne infections can lead to a state where the body becomes permanently
or persistently infected, and the micro-organism can be found in the blood and other body fluids
over long periods of time.
Understanding the epidemiology of blood-borne infections is particularly important for those
infections that can be prevented by vaccination. A goal of the World Health Organization is to
have all children vaccinated to prevent hepatitis B infection. This would ultimately eliminate the
infection. In Ontario, hepatitis B vaccine has been routine for 12-year-olds since 1994. It is also
provided to infants born to infected mothers and to other high risk groups.
In 2014, 143 Halton residents were diagnosed with a reportable blood-borne infection,
accounting for 7% of the total cases of reportable infectious diseases/infections that year
(Appendix B). Figure 16 shows the number of new cases of selected blood-borne infections
among Halton residents in 2014 compared to the previous five-year annual averages.
Number of reported cases
125
100
75
50
102
97
25
38
42
3
4
0
Hepatitis C
Hepatitis B - carriers
Hepatitis B - cases
Disease
2014
2009-2013 Annual Average
Figure 16: The number of selected blood-borne infections compared to previous five-year
annual average, Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
23
Hepatitis C
In 2014, there were 102 reported cases of hepatitis C virus (HCV) infection among Halton
residents. This accounts for 71% of the blood-borne infections presented in this report. On
average, there were 97 reported cases of HCV per year in the previous five years (Figure 16).
Hepatitis C is a blood-borne disease, primarily transmitted directly into the bloodstream by
contaminated injection equipment or products. HCV is directly related to the prevalence of
persons who routinely share injection equipment and to the prevalence of poor blood-borne
infection control procedures and practices in health care settings (the latter being more
applicable to developing countries). The World Health Organization estimates that some 130 to
170 million people (approximately 2% to 3% of the world population) are chronically infected
with HCV, which, like hepatitis B virus, is one of the most common global causes of chronic
hepatitis, cirrhosis, and liver cancer.
Since 2005, other than the small increase in 2007, both Ontario’s and Halton’s hepatitis C
incidence rates have generally been declining (Figure 17). In 2014, Halton’s age-standardized
incidence rate for hepatitis C of 19.5 cases per 100,000 population was significantly lower than
Ontario’s age-standardized incidence rate of 30.0 per 100,000 population.
Age-standardized incidence rate
(per 100,000)
40
30
20
10
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 17: Hepatitis C, age-standardized incidence rates per 100,000 population, Halton
residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
24
Hepatitis B
In 2014, there were 3 cases of acute hepatitis B infection in Halton residents compared to the
average of 4 per year in the previous five years. There were also 38 residents of Halton
identified as hepatitis B virus (HBV) carriers. On average per year, 42 hepatitis B carriers were
reported in the past five year period (Figure 16).
Hepatitis B cases are individuals who have the virus, can transmit to others and have the
symptoms of the acute infection. In contrast, a carrier has the virus in his/her system and can
transmit the virus to others, but a carrier shows no symptoms of the acute disease, though
he/she may have problems, recognized or unrecognized, associated with chronic infection.
Major modes of HBV transmission include sexual or close household contact (e.g., sharing of
razors or toothbrushes) with an infected person, perinatal mother-to-infant transmission,
injection drug use, and contaminated medical equipment exposure. Acute HBV infection causes
inflammation of the liver, though many infected people, especially the very young, have no
symptoms, while others have more serious illness with nausea and jaundice; the active infection
sometimes rapidly (within hours or days) develops into severe liver failure which may result in
death. Hepatitis B is classified as chronic when the infection persists longer than six months.
The Hepatitis B vaccine is very effective at preventing hepatitis B infection. Chronic HBV
infection is found in 0.5% of adults in North America and 0.1% to 20% in other parts of the
world. HBV infection becomes chronic in about 90% of infants infected at birth, 20% to 50% of
children infected from one to five years, and 1% to 10% of persons infected as older children
and adults. HBV may be the cause of up to 80% of all cases of hepatocellular carcinoma (liver
cancer) worldwide.
Over the last 10 years, both Halton’s and Ontario’s age-standardized incidence rates for
hepatitis B infection fluctuated around 1.0 case per 100,000 population (Figure 18). These
fluctuations are subject to the small number of reported cases on a year-to-year basis. In 2014,
the age-standardized incidence rate decreased to 0.5 cases per 100,000 population from the
rate of 1.2 per 100,000 in 2013 (Figure 18).
2014 Halton Region Infectious Disease Report
25
Age-standardized incidence rate
(per 100,000)
2.0
1.5
1.0
0.5
0.0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 18: Hepatitis B infection, age-standardized incidence rates per 100,000 population,
Halton residents compared to Ontario, 2004–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
26
Select Bacterial Diseases Transmitted by Direct Personal Contact or
Respiratory Routes
Diseases spread by close personal contact or respiratory routes, such as severe group A
streptococcal infections (only severe cases are reportable), tuberculosis, and meningococcal
disease, are most often passed between family members or people who share living
arrangements and/or close personal contact. Transmission may also occur among casual
contacts but is much less likely. When any of these diseases are diagnosed, the investigation
includes the identification and management of close contacts in order to prevent or reduce
additional illness.
In 2014, 36 Halton residents were diagnosed with a reportable infectious disease spread by
close personal contact or the respiratory route, accounting for 1.7% of the total cases of
reportable infectious diseases this year (Appendix B).
Figure 19 shows the number of new cases of selected bacterial diseases spread by close
contact or respiratory routes among Halton residents in 2014 compared to the previous five-year
annual averages.
Number of reported cases
25
20
15
23
10
16
14
5
7
5
7
1
1
0
Streptococcal infections, Tuberculosis - infectious
group A
Tuberculosis - noninfectious
Meningococcal disease
Disease
2014
2009-2013 Annual Average
Figure 19: Number of cases of selected bacterial diseases spread by close contact or
respiratory routes compared to previous five-year annual average, Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
27
Tuberculosis
In 2014, there were 11 reported cases of tuberculosis (infectious and non-infectious) in Halton
residents. Of these, 6 cases were infectious. On average, in the previous five-year period, 17
cases of tuberculosis (all types) per year were reported to the Halton Region Health Department
(Figure 20).
Tuberculosis is a mycobacterial disease that is a major cause of disability and death, especially
in developing countries. About 10% of those initially infected will eventually develop active
disease, half of them during the first two years following infection; 90% of untreated infected
individuals will never develop active TB. Worldwide, industrialized countries showed downward
trends in mortality and morbidity from TB for many years, but in the mid-1980s reported cases
stopped dropping; areas and population groups with a high prevalence of HIV infection or with
large numbers of persons from areas with a high prevalence of tuberculosis have since
experienced increased rates. In the low incidence areas, most TB disease in adults results from
reactivation of bacteria remaining from an old, initial infection. Worldwide, 1% to 2% of all TB
cases are due to multidrug resistant (MDR) strains; in some countries, such as parts of China,
India, and the former USSR, MDR-TB is a major problem.
Figure 20 shows the number of reported cases of tuberculosis, by type, among Halton residents
in 2014 compared to the previous five-year annual average.
Number of reported cases
20
15
10
17
5
16
11
6
7
5
0
Tuberculosis - Total
Tuberculosis - infectious
Tuberculosis - non-infectious
Disease
2014
2009-2013 Annual Average
Figure 20: Number of cases of tuberculosis compared to the previous five-year annual average,
Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
28
The ten-year trend in incidence of infectious tuberculosis shows fluctuation in rates for both
Ontario and Halton (Figure 21). Halton rates for infectious tuberculosis remained below
provincial rates. Between 2005 and 2008, the standardized incidence rates of infectious
tuberculosis in Halton fluctuated around an average annual rate of 1.2 cases per 100,000
population. These rates showed an increase from a rate of 1.0 per 100,000 population in 2009
to a rate of 2.3 per 100,000 in 2012. The incidence rate then declined to a rate of 1.2 per
100,000 population in 2014. The fluctuation in infectious tuberculosis incidence rates, in addition
to the year-to-year changes expected with the number of cases are low, may be related to
varying patterns of immigration to Halton Region from countries where tuberculosis is endemic.
Age-standardized incidence rate
(per 100,000)
6
4
2
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 21: Tuberculosis (infectious only), age-standardized incidence rate per 100,000
population, Halton residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
29
Group A Streptococcal Infections
In 2014, in Halton residents there were 23 reported cases of invasive group A streptococcal
infections (iGAS) compared to 14 cases reported on average per year in the previous five-year
period (Appendix B). Fluctuations in iGAS incidence are not unusual, given the relatively small
number of cases each year.
Group A streptococci are bacteria that commonly infect the skin and mucous membranes,
causing strep throat, impetigo, and other relatively mild infections. When these bacteria infect
body sites that are normally sterile, such as blood (bacteraemia), cerebrospinal fluid
(meningitis), and synovial fluid/joints, the disease is classified as iGAS disease. Serious
cellulitis, necrotizing fasciitis (flesh-eating disease), and streptococcal toxic shock syndrome are
forms of iGAS disease.
Halton’s age-standardized incidence rates for iGAS appear to be similar to Ontario rates but
show greater yearly variability due to the small number of cases. After a steady decline from
2005 to 2009, Halton’s age-standardized incidence rate increased again to a rate of 4.2 cases
per 100,000 population in 2014 (Figure 22), statistically significantly higher than the 2009 rate of
1.0 case per 100,000.
Age-standardized incidence rate
(per 100,000)
6
4
2
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 22: Severe group A streptococcal infections, age-standardized incidence rates per
100,000 population, Halton residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
30
Diseases Transmitted by Insects and Animals
Diseases spread by insects and other arthropods are called vector-borne diseases and are
caused by bacteria, parasites, and viruses. Blood-feeding arthropods such as fleas, mosquitoes,
midges, sandflies, ticks, and body-lice are the vectors that may transmit these diseases.
Fortunately, Canada’s seasonal, colder climate means that insect and other arthropod-borne
diseases are not as much of an issue as they are in tropical and sub-tropical regions. Many
vector-borne diseases pose a major health burden for developing countries. For example,
malaria is estimated to infect over 300 million people, killing one million per year. Although many
vector-borne diseases are rare in Ontario, surveillance for Lyme disease and West Nile virus
continues because, in addition to seasonal variation, climate change has the potential to impact
the local incidence of these diseases. The reportable diseases in this category include Lyme
disease, West Nile virus (WNV), viral hemorrhagic fevers, malaria, and yellow fever. The last
three diseases would generally present only as imported cases acquired through travel to
endemic areas.
In Halton in 2014, there were 14 reports of diseases transmitted by arthropods. There were 7
reports of malaria, 5 reports of Lyme disease, and 2 reports of West Nile virus (Figure 23). Of
the 5 Lyme disease cases, two were acquired in Ontario but outside of Halton, one was in
another province, and two were associated with travel outside of Canada.
Number of reported cases
10
8
6
4
8
7
7
5
2
4
2
0
Malaria
Lyme Disease
West Nile Virus
Disease
2014
2009-2013 Annual Average
Figure 23: Number of cases of diseases spread by arthropods compared to previous five-year
annual average, Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
31
Other Reportable Infectious Diseases
In 2014, there were 37 reports of other infectious diseases in Halton residents. These
accounted for 1.5% of all the reportable cases in that year (Appendix B). In 2014 acute flaccid
paralysis was added to the list of reportable diseases (Appendix A), and there was 1 case
reported to the Halton Region Health Department. There were no cases of Creutzfeldt-Jakob
disease or transmissible spongiform encephalopathy reported to the Halton Region Health
Department in 2014.
Number of reported cases
25
20
15
10
20
20
14
5
8
4
1
2
0
0
Meningitis
Encephalitis/Meningitis
Encephalitis
Acute Flaccid Paralysis
Disease
2014
2009-2013 Annual Average
Figure 24: Number of cases of meningitis and encephalitis compared to previous five-year
annual average, Halton residents, 2014.
Source: Integrated Public Health Information System [2009-2014], extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
32
Encephalitis and Meningitis
In 2014, 36 cases of encephalitis and/or meningitis were reported to the Halton Region Health
Department (Figure 25), compared to 32 cases reported on average per year in the previous
five-year period.
Encephalitis is an inflammation of the brain. There are many types of encephalitides, most of
which are caused by infection with viruses. Symptoms of encephalitis include sudden fever,
headache, vomiting, abnormal visual sensitivity to light, stiff neck and back, confusion,
drowsiness, clumsiness, unsteady gait, and irritability. Loss of consciousness, poor
responsiveness, seizures, muscle weakness, sudden severe dementia, memory loss,
withdrawal from social interaction, or impaired judgement may also occur.
Meningitis is an inflammation of the membranes (called meninges) that surround the brain and
spinal cord. Meningitis may be caused by many different viruses and bacteria, or by diseases
that can cause inflammation of tissues of the body without infection. Symptoms of meningitis,
which may appear suddenly, often include high fever, severe and persistent headache, stiff
neck, nausea, and vomiting as well as changes in behaviour such as confusion, sleepiness, and
difficulty waking up. In infants, symptoms of meningitis may include irritability or tiredness, poor
feeding, and fever.
While fluctuations are expected due to the small number of cases reported on a year-to-year
basis, the age-standardized incidence rates of encephalitis and meningitis combined has seen
an increase for both Halton and Ontario since 2009 and warrants monitoring. In 2014, the agestandardized incidence rate of 6.7 cases per 100,000 population among Halton residents was
statistically significantly higher than the Ontario age-standardized incidence rate of 4.2 cases
per 100,000 population (Table 2).
Age-standardized incidence rate
(per 100,000)
10
8
6
4
2
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
Year
Halton
Ontario
Figure 25: Encephalitis and Meningitis combined, age-standardized incidence rates per
100,000 population, Halton residents compared to Ontario, 2005–2014.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care,
Integrated Public Health System database, extracted by Public Health Ontario [March 30, 2015].
2014 Halton Region Infectious Disease Report
33
Part III: Hospital Utilization
The data presented in this hospital utilization section includes emergency department visits or
hospitalizations from the international classification of disease (ICD10) chapter “certain
infectious and parasitic diseases” (A00-B99) and influenza diagnoses from the “disease of
respiratory system” chapter (J09-J118). Therefore the infectious diseases captured in this
section are not limited to the reportable diseases presented in the first two sections of this
report.
Infectious Diseases – Emergency Department Visits
8000
8000
6000
6000
4000
4000
2000
2000
1183
1230
1250
1208
1322
2010
2011
2012
2013
2014
0
Number of ED visits
Age-standardized rate
(per 100,000)
Between 2010 and 2014 there was an average of 6,182 emergency department (ED) visits due
to infectious diseases per year in Halton. The number of ED visits attributed to infectious
diseases in Halton increased from 5,648 in 2010 to 6,861 in 2014, and the age-standardized
rate increased from 1,183 per 100,000 in 2010 to 1,322 per 100,000 in 2014 (Figure 26).
0
Year
Age-standardized rate (per 100,000)
Number of ED visits
Figure 26: Emergency department visits attributed to infectious diseases, number of visits and
age-standardized rates per 100,000 population, Halton residents, 2010-2014.
Sources: Population Estimates, IntelliHEALTH, Ministry of Health and Long-Term Care [2015], extracted March 21,
2015. National Ambulatory Care Reporting Centre, Ministry of Health and Long-Term Care, IntelliHEALTH Ontario
[2015], extracted March, 2015.
2014 Halton Region Infectious Disease Report
34
From 2010 to 2014, the age-specific rate of infectious diseases decreased as age increased
until ages 65 to 79, when the rate began to increase as age increased. Children aged 0 to 4 had
the highest age-specific rate of ED visits attributed to infectious diseases. This rate was almost
3 times higher than the age group with the second highest rate of ED visits due to infectious
diseases (ages 80+) (Figure 27).
Age-specific rate
(per 100,000)
6000
4000
5243
2000
1864
1110
931
585
0
0-4
5-19
20-44
45-64
Age group
951
65-79
80+
Figure 27: Emergency department visits attributed to infectious diseases, age-specific rates,
Halton residents, 2010-2014 combined.
Sources: Population Estimates, IntelliHEALTH, Ministry of Health and Long-Term Care [2015], extracted March 21,
2015. National Ambulatory Care Reporting Centre, Ontario Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario [2015], extracted March, 2015.
In Halton, between 2010 and 2014, the age-standardized rate of ED visits decreased as
neighbourhood income increased. These differences were statistically significant when
comparing all income groups to one another (Figure 28).
Age-standardized rate
(per 100,000)
2000
1500
1000
1814
1366
500
1230
0
Low
Middle
High
Neighbourhood income group
Figure 28: Emergency department visits attributed to infectious diseases, age-standardized
rates, by neighbourhood income group, Halton residents, 2010-2014 combined.
2014 Halton Region Infectious Disease Report
35
Infectious Diseases – Hospitalizations
800
800
600
600
400
400
200
200
109
109
102
119
120
2010
2011
2012
Year
2013
2014
0
0
Age-standardized rate (per 100,000)
Number of hospitalizations
Age-standardized rate
(per 100,000)
Between 2010 and 2014 there was an average of 656 hospitalizations due to infectious
diseases per year among Halton residents. The number of hospitalizations attributed to
infectious diseases increased from 591 in 2010 to 753 in 2014 and the age-standardized rate of
hospitalizations increased from 109 per 100,000 in 2010 to 120 per 100,000 in 2014 (Figure 29).
Number of ED visits
Figure 29: Hospitalizations attributed to infectious diseases, number of visits and agestandardized rates per 100,000 population, Halton residents, 2010-2014.
Sources: Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted
March 21, 2015. National Ambulatory Care Reporting Centre, Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario [2015], extracted March, 2015.
In Halton, between 2010 and 2014, adults aged 80+ had the highest age-specific rate of
hospitalizations due to infectious diseases, followed by children aged 0 to 4 and adults aged 65
to 79. There were fewer hospitalizations among older children (aged 5 to 19) and adults aged
20 to 44 and 45 to 64 compared to the youngest and oldest age groups (Figure 30).
Age-specific rate
(per 100,000)
1000
800
600
853
400
200
296
53
276
47
81
0
0-4
5-19
20-44
45-64
Age group
65-79
80+
Figure 30: Hospitalizations attributed to infectious diseases, age-specific rates, Halton
residents, 2010-2014 combined.
Sources: Population Estimates, IntelliHEALTH, Ministry of Health and Long-Term Care [2015], extracted March 21,
2015. National Ambulatory Care Reporting Centre, Ontario Ministry of Health and Long-Term Care, IntelliHEALTH
Ontario [2015], extracted March, 2015.
2014 Halton Region Infectious Disease Report
36
In Halton, between 2010 and 2014, the age-standardized rate of hospitalizations due to
infectious diseases showed a similar pattern as seen with ED visits and decreased as
neighbourhood income level increased. Residents in the high income group had a significantly
lower age-standardized rate of hospitalizations (108 per 100,000) compared to the middle and
low income groups (Figure 31).
Age-standardized rate
(per 100,000)
200
150
100
163
134
108
50
0
Low
Middle
Neighbourhood income group
High
Figure 31: Hospitalizations attributed to infectious diseases, age-standardized rates, by
neighbourhood income group, Halton residents, 2010-2014 combined.

Sources:
ED and Hospital data: National Ambulatory Care Reporting Centre [2010-2014], Ontario Ministry of Health and Long-Term Care,
IntelliHealth Ontario [2015], extracted March, 2015.
Population estimates and Projections for Halton: Population Estimates and Projections [2010-2014], Ontario Ministry of Health and
Long-Term Care, IntelliHEALTH Ontario [2015], extracted March 21, 2015.
Population estimates by DA for income calculation: Statistics Canada, 2011 Census of Population, Statistics Canada Catalogue
no.98-311-XCB2011018.
Income indicator: Statistics Canada, 2013. Canadian National Household Survey (NHS) Profile. 2011 National Household Survey,
Statistics Canada Catalogue no.99-004-XWE. Ottawa. Released September 11, 2013.
Postal code conversion file (PCCF): Statistics Canada, 2011 Census of Population, Postal Code Conversion File (PCCF). Ottawa.
Released July 20 2011.
Note on Neighbourhood Income groups:
The National Household Survey (NHS) indicator “in bottom half of the Canadian distribution” was used as
a basis for our neighbourhood income groups. The term neighbourhood refers to a single dissemination
area (DA). This indicator provides the percent of households per DA that were in the bottom half of the
Canadian distribution based on adjusted household income. Using this value, we ranked all of the DAs in
Canada into 10 equal groups (deciles), and then ranked them as low (deciles 1-3), middle (deciles 4-7) or
high (deciles 8-10). When looking at Halton alone, this resulted in an unequal number of DAs in each
income group since the deciles are based on the national ranking.
Each ED and hospital record extracted from IntelliHEALTH was assigned to the appropriate DA by using
the provided postal code along with the postal code conversion file (2011, PCCF). Since the actual
income of individuals is not known, and may vary from their neighbourhood income, misclassification of
individuals based on their neighbourhood income instead of household income may diminish the
association between income and injury.
Approximately 2.6% of hospital records and 2.7% of ED records were not included in the income analysis
due to no postal code provided, incomplete postal codes, postal codes not matching in the PCCF+ file, or
DAs being supressed due to small response from the NHS.
2014 Halton Region Infectious Disease Report
37
Part IV: Outbreak Investigations
Halton Region Health Department staff investigate outbreaks under the mandate “to decrease
or eliminate the risks to health presented by infectious diseases” as outlined in the Health
Protection and Promotion Act. Although many infectious disease investigations involve single
sporadic cases, that is, that cannot be linked to other cases, contaminated food or water or
person-to-person contact can result in clusters of illness affecting large numbers of people.
Some outbreaks have required significant Halton Region Health Department resources,
especially those with longer duration.
All institutional gastroenteric and respiratory outbreaks are reportable to the Health Department
regardless of whether or not the specific disease is known or reportable. Outbreaks of
gastrointestinal illness in institutions are most frequently caused by viruses such as norovirus,
and other caliciviruses, rotavirus, astrovirus, enteric adenovirus, and other viruses. However,
bacteria and other pathogens may cause outbreaks as well. Outbreaks of respiratory infections
in institutions are caused by a variety of respiratory viruses such as influenza A and B,
respiratory syncytial virus (RSV), parainfluenza, rhinovirus, coronavirus, human
metapneumovirus, and adenovirus. Examples of bacteria that cause respiratory outbreaks in
institutions include Chlamydia pneumoniae, Legionella spp., and Mycoplasm pneumoniae
(atypical pneumonia).
Since each outbreak requires its own case definition, health unit staff collaborate with the facility
to develop a case definition based on the outbreak’s characteristics and any agent identified
through laboratory testing. Health unit staff also provide ongoing support to the facility during the
outbreak investigation, confirmation, and management to ensure that infection prevention and
control measures are used to minimize the duration of outbreaks and to minimize the impact of
the outbreak on both staff and residents.
2014 Halton Region Infectious Disease Report
38
Outbreaks by Location
In 2014, the Halton Region Health Department investigated a total of 111 reported outbreaks,
associated with 2,120 ill persons. Forty-eight of these outbreaks occurred in Burlington, 34 in
Oakville, 15 in Milton, and 13 in Halton Hills (Figure 32). There was one outbreak that involved a
facility outside of Halton Region but included Halton residents.
30
Number of outbreaks
25
20
15
10
28
21
20
13
5
6
7
8
7
0
Burlington
Halton Hills
Milton
Oakville
Municipality
Enteric
Respiratory
Figure 32: Type of outbreak by municipality, Halton Region, 2014.
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
Of the total reported outbreaks investigated in Halton, 43% occurred in long-term care homes,
25% occurred in child care centres, 24% in retirement homes, 4% in hospitals, and 4% in the
community such as community events (Figure 33).
2014 Halton Region Infectious Disease Report
39
50
% of outbreaks
40
30
20
43
25
24
10
4
4
Hospital
Community
0
Long-Term Care
Child Care
Retirement Home
Type of location
Figure 33: Outbreaks by type of location, Halton Region, 2014.
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
Fifty-six the 111 reported outbreaks (50.5%) were respiratory and 55 (49.5%) were enteric
(gastrointestinal tract infections). Table 3 shows the distribution of outbreaks by type of outbreak
and location of the outbreak. All reported outbreaks in child care facilities were enteric.
Table 3: Number of outbreaks, by type of outbreak and location, Halton Region, 2014.
Location of Outbreak
Long-term Care
Child Care
Retirement Home
Hospital
Community
Total
Respiratory
Enteric
Total
38
0
15
2
1
56
10
28
12
2
3
55
48
28
27
4
4
111
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
2014 Halton Region Infectious Disease Report
40
Respiratory Outbreaks
Of the 56 respiratory outbreaks investigated in 2014 in Halton Region, 51 (91%) had a
laboratory-confirmed agent. In 5 (9%) of the outbreaks more than one agent was identified.
Influenza was identified in 45% of the outbreaks; rhinovirus in 23%; coronavirus and hMPV
(human metapneumovirus) in 11% each, and parainfluenza and RSV (respiratory syncytial
virus) in 4% each (Figure 34). For 9% of the outbreaks the causative agent was not identified.
% of respiratory outbreaks
30
20
25
10
23
21
11
11
9
4
0
4
2
Agent responsible
Figure 34: Proportion of respiratory outbreaks by causative agent (laboratory-confirmed or
suspected), Halton Region, 2014.
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
2014 Halton Region Infectious Disease Report
41
Enteric Outbreaks
Of the 55 enteric outbreaks investigated in 2014 in Halton Region, 30 (55%) had a laboratoryconfirmed agent. Norovirus was laboratory confirmed in 27 (49%) of the total outbreaks and
suspected in another 4 (7%) outbreaks (Figure 35). Norovirus and rotavirus are not reportable
diseases, and so are not reported as individual cases in the provincial infectious disease
database (iPHIS). However, all outbreaks of gastroenteritis in institutional setting are reportable
and entered into iPHIS as summary information.
60
% of enteric outbreaks
50
40
30
56
20
38
10
2
2
2
Adenovirus
Hep A
Rotavirus
0
Norovirus
Unknown
Agent responsible
Figure 35: Proportion of enteric outbreaks by causative agent (laboratory-confirmed or
suspected), Halton Region, 2014.
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
2014 Halton Region Infectious Disease Report
42
Outbreak Trends
The most common time period associated with outbreaks was the winter months, as seen in
Figure 36. Half of the outbreaks (51%) began in January, February, or December.
Number of outbreaks
25
20
4
15
17
6
10
17
5
0
11
5
1
8
6
5
3
1
2
4
1
3
3
4
1
2
2
5
Month of onset
Enteric
Respiratory
Figure 36: Number of outbreaks by type and month of onset, Halton Region, 2014.
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
The duration of outbreaks varied from less than one week up to five weeks and longer (Figure
37). Forty-two percent of enteric outbreaks lasted one week or less while 45% of respiratory
outbreaks lasted 2 weeks. Ten percent of enteric and respiratory outbreaks lasted four weeks or
longer.
2014 Halton Region Infectious Disease Report
43
Number of outbreaks
50
40
30
19
25
20
10
6
23
16
10
3
3
3
3
3
4
5+
0
1 week or less
2
Outbreak duration (in weeks)
Enteric
Respiratory
Figure 37: Number of outbreaks by type and duration, Halton Region, 2014.
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
While there is no long-term trend apparent, the number of outbreaks in Halton decreased by
21% from the 140 outbreaks investigated in 2013 to the 111 outbreaks investigated in 2014
(Table 4). Compared to the previous 5 year average (between 2009 and 2013) there were on
average 123 outbreaks investigated annually in Halton Region.
Table 4: Number of outbreaks by location, Halton Region, 2009–2014.
Location of Outbreak
2009
2010
2011
2012
2013
Long-term Care
34
62
42
51
75
Child Care
69
54
48
29
35
Retirement Home
17
11
16
15
21
Hospital
2
3
5
4
4
Community
4
2
1
2
5
Food Premise
1
1
0
0
0
Total
127
133
112
101
140
2014
48
28
27
4
4
0
111
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
2014 Halton Region Infectious Disease Report
44
Number of Cases Investigated
Of the total 2,120 people who became ill, 1,695 (80%) were clients and 425 were staff of the
affected premises (Table 5). In total, 9,600 clients and 6,082 staff were “at risk of becoming ill”
because of an outbreak in their facilities and subject to increased infection control procedures.
Table 5: Total number of clients and staff who were at risk and who were ill, by location of the
outbreak, respiratory and enteric outbreaks combined, Halton Region, 2014.
Location of Outbreak
Child Care
Long-term Care
Retirement Home
Hospital
Community
Total
Clients
At Risk
2,203
3,824
3,274
124
175
9,600
Staff
Ill
519
574
515
18
69
1,695
At Risk
849
3,515
1,598
110
10
6,082
Ill
161
189
66
9
0
425
Source: 2014 Outbreak Activity Log, Halton Region Health Department.
2014 Halton Region Infectious Disease Report
45
Appendix A: O. Reg 559/91 under the Health Protection and Promotion Act
ONTARIO REGULATION 559/91
SPECIFICATION OF REPORTABLE DISEASES
Last amendment: O. Reg. 315/13.
This is the English version of a bilingual regulation.
1. The following diseases are specified as reportable diseases for the purposes of the Act:
Acquired Immunodeficiency Syndrome (AIDS)
Acute Flaccid Paralysis
Amebiasis
Anthrax
Botulism
Brucellosis
Campylobacter enteritis
Chancroid
Chickenpox (Varicella)
Chlamydia trachomatis infections
Cholera
Clostridium difficile associated disease (CDAD) outbreaks in public hospitals
Creutzfeldt-Jakob Disease, all types
Cryptosporidiosis
Cyclosporiasis
Diphtheria
Encephalitis, including,
i. Primary, viral
ii. Post-infectious
iii. Vaccine-related
iv. Subacute sclerosing panencephalitis
v. Unspecified
Food poisoning, all causes
Gastroenteritis, institutional outbreaks
Giardiasis, except asymptomatic cases
Gonorrhoea
Group A Streptococcal disease, invasive
Group B Streptococcal disease, neonatal
Haemophilus influenzae b disease, invasive
Hantavirus pulmonary syndrome
Hemorrhagic fevers, including,
i. Ebola virus disease
ii. Marburg virus disease
iii. Other viral causes
Hepatitis, viral,
i. Hepatitis A
ii. Hepatitis B
iii. Hepatitis C
Influenza
Lassa Fever
Legionellosis
Leprosy
Listeriosis
2014 Halton Region Infectious Disease Report
46
Lyme Disease
Malaria
Measles
Meningitis, acute,
i. bacterial
ii. viral
iii. other
Meningococcal disease, invasive
Mumps
Ophthalmia neonatorum
Paralytic Shellfish Poisoning
Paratyphoid Fever
Pertussis (Whooping Cough)
Plague
Pneumococcal disease, invasive
Poliomyelitis, acute
Psittacosis/Ornithosis
Q Fever
Rabies
Respiratory infection outbreaks in institutions
Rubella
Rubella, congenital syndrome
Salmonellosis
Severe Acute Respiratory Syndrome (SARS)
Shigellosis
Smallpox
Syphilis
Tetanus
Trichinosis
Tuberculosis
Tularemia
Typhoid Fever
Verotoxin-producing E. coli infection indicator conditions, including Haemolytic Uraemic
Syndrome (HUS)
West Nile Virus Illness
Yellow Fever
Yersiniosis
O. Reg. 559/91, s. 1; O. Reg. 205/95, s. 1; O. Reg. 129/96, s. 1; O. Reg. 381/01, s. 1; O. Reg. 432/01,
s. 1; O. Reg. 81/03, s. 1; O. Reg. 96/03, s. 1; O. Reg. 365/06, s. 1; O. Reg. 304/08, s. 1; O. Reg. 315/13,
s. 1.
Omitted (revokes other Regulations). O. Reg. 559/91, s. 2.
2014 Halton Region Infectious Disease Report
47
Appendix B: The Number of Reported Cases of Communicable Disease in
2014 compared to 2013 and the previous 5-year average (2009–2013), and
the Age-Standardized Rates per 100,000 Population, Halton residents.
(Statistically significant changes between 2013 and 2014 are indicated by up- or down- arrows.)
Disease
Age-standardized Rates
(95% confidence intervals)
2014
2013
# of
Cases
2014
# of
Cases
2013
Prev. 5yr avg.
15
0
379
1
0
14
0
0
450
20
0
292
6
2
10
0
25
355
12
0
284
1
3
8
0
35
345
2.7 (1.3-4.1)
0
67.2 (60.2-74.2)
0.2 (0.2-0.6)
0
2.6 (1.2-4.0)
0
4.2 (2.4-5.9)
4.0 (2.2-5.8)
0
50.3 (44.3-56.3)
1.2 (0.2-2.1)
0.4 (0.2-1.0)
2.1 (0.8-3.4)
0
4.2 (2.5-5.8)
↔
↔
↑
↔
↑
↔
↔
↔
18
128
11
13
46
6
7
3
0
3
118
9
2
4
9
377
19
138
6
5
43
5
11
0
n/a
0
91
10
1
3
2
334
17
134
8
5
50
4
8
2
3.2 (1.7-4.7)
22.9 (18.8-27.0)
2.4 (1.0-3.9)
2.3 (1.0-3.6)
8.2 (5.8-10.7)
1.1 (0.2-2.1)
0.9 (0.2-1.6)
0.4 (0.1-0.9)
0
0.7 (0.1-1.4)
22.4 (18.2-26.5)
1.8 (0.6-3.0)
0.4 (0.2-1.0)
0.9 (0-1.9)
2.0 (0.7-3.4)
3.8 (2.0-5.6)
26.6 (22.0-31.2)
1.2 (0.2-2.2)
0.7 (0.1-1.3)
8.6 (5.9-11.1)
1.0 (0.1-1.9)
1.6 (0.6-2.6)
0
n/a
0
17.4 (13.8-21.2)
2.1 (0.8-3.5)
0.3 (0.3-0.8)
0.5 (0.1-1.0)
0.6 (0.1-1.3)
↔
↔
↔
↔
↔
↔
↔
↑
n/a
↑
↔
↔
↔
↔
↔
180.7 (168.2193.3)
27.8 (22.9-32.8)
2.5 (1.1-4.0)
0.2 (0.1-0.6)
7.2 (4.8-9.6)
2.0 (0.7-3.3)
5.2 (3.2-7.2)
171.3 (158.8183.8)
14.4 (10.8-18.2)
2.1 (0.9-3.4)
0.1 (0.1-0.4)
6.5 (4.2-8.9)
3.3 (1.6-5.0)
3.3 (1.6-4.9)
↔
Change
Vaccine-Preventable Diseases
Chickenpox
Haemophilus influenzae type b (HIB)
Influenza (Sept. 2012-August 2013)
Measles
Mumps
Pertussis
Rubella
Streptococcus pneumoniae – invasive
TOTAL
Food and Water-borne Diseases
Amebiasis
Campylobacteriosis
Cryptosporidiosis
Cyclosporiasis
Giardiasis
Hepatitis A
Legionellosis
Listeriosis
Paralytic Shellfish Poisoning
Paratyphoid fever
Salmonellosis
Shigellosis
Typhoid fever
Verotoxin-producing Escherichia coli
Yersiniosis
TOTAL
2
100
7
1
4
9
Sexually-transmitted Infections and Blood-borne Diseases
Chlamydia
822
747
771
Gonorrhea
HIV
AIDS
Syphilis – total
Syphilis – infectious
Syphilis – non-infectious
TOTAL
129
13
2
39
10
29
1,005
63
12
1
32
15
17
855
66
9
2
44
10
34
892
2014 Halton Region Infectious Disease Report
↑
↔
↔
↔
↔
↔
48
Disease
Age-standardized Rates
(95% confidence intervals)
2014
2013
# of
Cases
2014
# of
Cases
2013
Prev. 5yr avg.
38
3
102
143
39
6
96
141
42
4
96
142
6.7 (4.5-8.9)
0.5 (0.08-1.0)
18.9 (15.1-22.8)
7.3 (4.9-9.6)
1.2 (0.2-2.1)
18.0 (14.2-21.8)
↔
↔
↔
1
23
12
7
5
36
0
18
15
11
4
33
1
14
17
9
7
32
0.2 (0.2-0.6)
4.2 (2.4-5.9)
2.0 (0.9-3.2)
1.2 (0.3-2.2)
0.8 (0.1-1.6)
0
3.1 (1.6-4.6)
2.9 (1.4-4.4)
2.1 (0.8-3.3)
0.8 (0-1.7)
↑
↔
↔
↔
↔
5
7
2
0
14
7
6
2
1
16
7
4
8
1
20
0.9 (0.1-1.9)
1.5 (0.4-2.6)
0.3 (0.1-0.7)
0
1.2 (0.3-2.2)
1.2 (0.2-2.2)
0.3 (0.1-0.7)
0.1 (0.1-0.4)
↔
↔
↔

0
0
1
1
2
2
0
0.2 (0.2-0.6)

1
2
20
14
0
36
n/a
10
28
5
0
43
n/a
8
20
4
0
0
0.3 (0.1-0.8)
4.1 (2.2-5.9)
2.4 (1.1-3.7)
0
n/a
1.6 (0.6-2.6)
5.2 (3.2-7.1)
1.0 (0.1-1.9)
0
Change
Blood-borne Infections
Hepatitis B – carriers
Hepatitis B – cases
Hepatitis C
TOTAL
Diseases Spread by Close Contact
Meningococcal disease
Streptococcal infections, group A
(Tuberculosis – total)
Tuberculosis – infectious
(Tuberculosis – non-infectious)
TOTAL
Zoonotic and Exotic Diseases
Lyme disease
Malaria
West Nile virus
Q Fever
TOTAL
Neonatal
Streptococcal infections, group B
TOTAL
Other
Acute Flaccid Paralysis
Encephalitis
Meningitis
Encephalitis/Meningitis
Transmissible spongiform encephalopathy
TOTAL
n/a
↔
↔
↔
n/a
Note: Change - (↔) indicates that there is no significant difference between Halton and Ontario; (↓) indicates that the
age-standardized incidence rate in Halton is significantly lower than Ontario; and, (↑) indicates that the agestandardized incidence rate in Halton is significantly higher than Ontario. Non-overlapping confidence intervals (CIs)
for the 2013 rate and the 2014 rate indicated a statistically significant difference. This approach is conservative and
chosen to help account for the multiple comparisons being made in this report. Diseases no longer reportable in 2014
are not included in this appendix but are included in the total for 2013.
Sources: Reportable Disease Information System [2004-2005], extracted May 15, 2007; Integrated Public Health
Information System [2005-2014], extracted March 23, 2015; Population Estimates, IntelliHealth, Ministry of Health
and Long-Term Care [2015], extracted March 21, 2015.
2014 Halton Region Infectious Disease Report
49
Appendix C: Summary of rare reportable infectious diseases and those
with low incidence, Halton residents, 2000–2014.
Reportable
Infectious Disease
Disease Category
AIDS
Sexually-transmitted infections
2014
Total number of
reported cases for
period 2000-2014
24
Botulism
Food-borne
2012
1
Brucellosis
Vectorborne and zoonotic
2009
3
Cholera
Water-borne
2008
1
Haemophilus
influenzae type b
(HIB),
Vaccine-preventable diseases
2011
3
2011
1
2014
11
2014
33
Neonatal
1993
0
Zoonotic and exotic diseases
Vaccine-preventable diseases
2013
2012
6
4
before 1990
0
Diseases spread by close
contact
2003
1
Neonatal
2013
30
Syphilis, congenital
Neonatal
before 1990
0
Tetanus
Typhoid fever
Vaccine-preventable diseases
Water-borne diseases
2011
2014
1
18
Leprosy
Measles
Meningococcal
disease
Ophthalmia
neonatorum
Q Fever
Rubella
Rubella, congenital
syndrome
Severe acute
respiratory syndrome
(SARS)
Streptococcal
infection, group B
Diseases spread by close
contact
Vaccine-preventable diseases
Diseases spread by close
contact
Neonatal
Year of last
report
Sources: Reportable Diseases Information System [1995-2005]; Integrated Public Health Information System [2015],
extracted March 23, 2015.
2014 Halton Region Infectious Disease Report
50
HE-14030