Download typhoid fever & control measures

TYPHOID FEVER & CONTROL MEASURES
Dr . I. Selvaraj
Mary Mallon
(wearing glasses)
photographed
with
bacteriologist
Emma Sherman
on North Brother
Island in 1931 or
1932, over 15
years after she
had been
quarantined there
permanently.
In 1906, Irish immigrant Mary Mallon worked as a cook in the
Oyster Bay summer home of New York banker Charles Henry
Warren and his family. By the end of the summer, six members of
the household had contracted typhoid fever. The Warrens hired
sanitary engineer, George Soper, to determine the source of the
disease. Soper concluded that Mallon, while immune herself to the
disease, was its carrier. For three years, she was isolated on North
Brother Island, near Rikers Island, earning the nickname
"Typhoid Mary." Instructed not to cook for others upon her release,
she nevertheless changed her name and became a cook at a
maternity hospital in Manhattan. At least 25 staff members
contracted typhoid. "Typhoid Mary" returned to North Brother
Island, where she lived alone for 23 years, until her death in 1938.
She is shown here on the island in an undated photo. She died of a
stroke after 23 years in quarantine.
• Typhos in Greek means ,smoke and typhus
fever got its name from smoke that was
believed to cause it. Typhoid means typhuslike and thus the name given to this disease.
• The term Typhoid was given by Louis 1829
to distinguish it from typhus fever.
• It is a disease of poor environmental
sanitation and hence occurs in parts of the
world where water supply is unsafe and
sanitation is substandard.
The term enteric fever or typhoid fever is a
communicable disease, found only in man
and includes both typhoid fever caused by
S.Typhi and paratyphoid fever caused by
S.Paratyphi A, B and C . It is an acute
generalized infection of the reticulo
endothelial system, intestinal lymphoid
tissue,
and
the
gall
bladder.
EPIDEMIOLOGY
According to the World Health Organization,
globally some 16 million cases occur annually
resulting in more than 600,000 deaths. More than
62% of the global cases occur in Asia, of which, 7
million occur annually in South East Asia. Other
countries with a high incidence include Central and
South America, Africa and Papua New Guinea.
• The incidence of this disease in UK is reported to be just
one case per 1,00,000 population.
• In 1994, for example, 26,55,000 cases (incidence : 500
cases/ million) were reported from Africa with 1,30,000
deaths
• The mean incidence of typhoid fever in developing
countries is estimated between 150 cases/million
population/year in Latin America to 1000cases/million
population/year in some Asian countries.
India
• World largest outbreak of typhoid in SANGLI on
December 1975 to February 1976 . This disease is
endemic in India
• 1992 :
3,52,980 cases with 735 deaths
• 1993 :
3,57,452 cases and 888 deaths
• 1994 :
2,78,451 cases and 304 deaths
• Case fatality rate due to typhoid has been varying
between 1.1% to 2.5 % in last few years.
In 1885, pioneering american veterinary
scientist, daniel E. Salmon, discovered the first
strain of salmonella from the intestine of a pig.
This strain was called salmonella choleraesuis,
It is still used to describe the genus and species
of this common human pathogen.
• In 1880s, the typhoid bacillus was first
discovered by Eberth in spleen sections and
mesenteric lymph nodes from a patient who
died from typhoid.
• Robert Koch confirmed a related finding and
succeeded in cultivating the bacterium in
1881.
• Serodiagnosis of typhoid was thus made
possible by 1896.
• Wright and his team prepared heat killed
vaccine from S.Typhi in 1896
• Salmonellae are gram – ve rods, facultatively aerobic, Motile
with peritrichate flagella, non-spore-forming
• 1-3μm ×0.5μm in size
• Salmonella currently comprise 2000 serotypes
• Two groups a) Enteric fever group
b) Food poisoning group
The bacilli are killed at 55ºc in one hour or at 60ºc in 15
minutes.
They are killed within 5 minutes by mercuric cholride or 5%
phenol
Boiling or chlorination of water and pasteurization of milk
destroy the bacilli
The proportion of typhoid to paratyphoid A is 10:1,
Paratyphoid B is rare and paratyphoid C is very rare in
India
Salmonella enterica.
• Age group : Typhoid fever may occur at
any age but it is considered to be a
disease mainly of children and young
adults. In endemic areas, the highest
attack rate occurs in children aged 8-13
years. In a recent study from slums of
Delhi, it was found that contrary to popular
belief, the disease affects even children
aged 1-5 years
Gender and race : Typhoid fever cases are
more commonly seen in males than in
females. On the contrary, females have a
special predilection to become chronic
carriers.
Occupation : Certain categories of persons
handling the infective material and live
cultures of S. typhi are at increased risk of
acquiring infection.
Socio-economic factors : It is a disease of
poverty as it is often associated with
inadequate sanitation facilities and unsafe
water supplies.
• Environmental factors : Though the cases
are observed through out the year, the
peak incidence of typhoid fever is reported
during July - September. This period
coincides with the rainy season and a
substantial increase in fly population.
• Social factors : pollution of drinking water
supplies, open air defecation, and urination,
low standards of food and personal
hygiene, and health ignorance.
Nutritional status :Malnutrition may enhance the
susceptibility to typhoid fever by altering the
intestinal flora or other host defences.
Incubation period : Usually 10-14 days but it may
be as short as 3 days or as long as 21 days
depending upon the dose of the inoculums.
Reservoir of infection : Man is the only
known reservoir of infection - cases or
carriers.
Period of communicability: A case is
infectious as long as the bacilli appear in
stool or urine.
Mode of transmission : The disease is transmitted by
faeco - oral route or urine – oral routes – either
directly through hands soiled with faeces or urine of
cases or carriers or indirectly by ingestion of
contaminated water, milk, food, or through flies.
Contaminated ice, ice-creams, and milk products are a
rich source of infection.
Carriers may be temporary or chronic.
Temporary (convalescent or incubatory)
carriers usually excrete bacilli up to 6-8
weeks. By the end of one year, 3-4 per
cent of cases continue to excrete typhoid
bacilli.
Persons who excrete the bacilli for more
than a year after a clinical attack are called
chronic carriers.
Salmonella typhi infecting the body via the
Peyer's patches of the small intestine. The
bacteria migrates to mesenteric lymph nodes and
arrive via the blood in the liver and spleen during
the first exposure. After multiple replication in
the above locations, the bacteria Migrates back
into the Peyer's patches of the small intestine for
the secondary exposure and consequently the
clinical symptoms are seen. Inflammation in the
small intestine leads to ulcers and necrosis.
• First week: The disease classically presents with step-ladder
fashion rise in temperature (40 - 41°C) over 4 to 5 days,
accompanied by headache, vague abdominal pain, and
constipation.
• Second week: Between the 7 th -10 th day of illness, mild hepato-
splenomegally occurs in majority of patients. Relative
bradycardia may occur and rose-spots may be seen.
• Third week: The patient will appear in the "typhoid state"
which is a state of prolonged apathy, toxaemia, delirium,
disorientation and/or coma. Diarrhoea will then become apparent.
If left untreated by this time, there is a high risk (5-10%) of
intestinal hemorrhage and perforation.
• Rare complications:
Typhoid hepatitis,Emphyema, Osteomyelitis, and Psychosis.
2-5% patients may become Gall-bladder carriers
Rose spots
DIAGNOSIS
• Typhoid should be considered in any patient with
prolonged unexplained fever in endemic areas and in
those with a history of recent travel to endemic area.
• Prolonged fever, rose spots, relative bradycardia and
leucopenia make typhoid strongly suggestive.
• Widal test measures titres of serum agglutinins
against somatic (O) and flagellar (H) antigens which
usually begin to appear during the 2nd week. In the
absence of recent immunization, a high titre of
antibody to O antigen > 1:640 is suggestive but not
specific.
• Polymerase chain reaction (PCR) can be performed on
peripheral mononuclear cells. The test is more sensitive
than blood culture alone (92% compared with 50-70%)
but requires significant technical expertise
• Blood cultures are positive in 70-80% of cases during
the 1st week.
• Stool and urine cultures are usually positive (45-75%)
during the 2nd-3rd week.
• Bone marrow aspirate cultures give the best
confirmation (85-95%)
• The tracing of carriers in cities by sewer – swab
technique
RAPID TESTS FOR DIAGNOSING TYPHOID
• Typhidot test that detects presence of IgM and IgG in
one hour (sensitivity>95%, Specificity 75%)
• Typhidot-M, that detects IgM only (sensitivity 90%
and specificity 93%)
• Typhidot rapid (sensitivity 85% and Specificity 99%)
is a rapid 15 minute immunochromatographic test to
detect IgM.
• IgM dipstick test
Wilson and Blair bismuth sulphite medium jet black colony with a
metallic sheen
Differential Diagnosis
Other disease or conditions that need to be eliminated
Other infectious diseases
Other problems
•Lymphoma
•Brucellosis
•Infectious mononucleosis
•Leptospirosis
•Malaria
•Miliary tuberculosis
•Rickettsioses
•Tularemia
•Viral hepatitis
Management of typhoid fever:
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General: Supportive care includes
Maintenance of adequate hydration.
Antipyretics.
Appropriate nutrition.
Specific: Antimicrobial therapy is the mainstay
treatment. Selection of antibiotic should be based on
its efficacy, availability and cost.
• Chloramphenicol , Ampicillin ,Amoxicillin ,
Trimethoprim &Sulphamethoxazole
,Fluroquinolones
• In case of quinolone resistance – Azithromycin, 3rd
generation cephalosporins (ceftriaxone)
Control of Typhoid fever
MEASURES DIRECTED TO RESERVOIR
a) Case detection and treatment
b) Isolation
c)Disinfection of stools and urine
d)Detection & treatment of carriers
MEASURES AT ROUTES OF TRANSMISSION
a) Water sanitation
b) Food sanitation
c) Excreta disposal
d) Fly control
MEASURES FOR SUSCEPTIBLES
a) immunoprophylaxis
b)health education
HEALTH PROMOTION
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Keep the premises and kitchen utensils clean.
Dispose rubbish properly.
Keep hands clean and fingernails trimmed.
Wash hands properly with soap and water before eating or handling
food, and after toilet or changing diapers.
Drinking water should be from the mains and preferably boiled.
Purchase fresh food from reliable sources. Do not patronize illegal
hawkers.
Avoid high-risk food like shellfish, raw food or semi-cooked food.
Wear clean washable aprons and caps during food preparation.
Clean and wash food thoroughly.
Scrub and rinse shellfish in clean water. Immerse them in clean water
for sometime to allow self-purification.
Remove the viscera if appropriate
Cont………
• Store perishable food in refrigerator, well covered.
• Handle and store raw and cooked food especially seafood
separately (upper compartment of the refrigerator for
cooked food and lower compartment for raw food) to avoid
cross contamination.
• Clean and defrost refrigerator regularly and keep the
temperature at or below 4ºc
• Cook food thoroughly.
• Do not handle cooked food with bare hands; wear gloves if
necessary.
• Consume food as soon as it is done.
• If necessary, refrigerate cooked leftover food and consume
as soon as possible. Reheat thoroughly before
consumption. Discard any addled food items.
• Exclude typhoid carrier from handling food and from
providing care to children.
Specific protection
THREE TYPES OF VACCINES
1. Injectable Typhoid vaccine
(TYPHIM –Vi,TYPHIVAX)
2. The live oral vaccine (TYPHORAL)
3. TAB vaccine
Injectable Typhim -Vi
1. This single-dose injectable typhoid vaccine, from the
bacterial capsule of S. typhi strain of Ty21a.
2. This vaccine is recommended for use in children
over 2 years of age.
3. Sub-cutaneous or intramuscular injection
4. Efficacy : 64% -72%
Typhoral
This is a live-attenuated-bacteria vaccine manufactured
from the Ty21a strain of S. typhi.
2. The efficacy rate of the oral typhoid vaccine ranges
from 50-80%
3. Not recommended for use in children younger than 6
years of age.
4. The course consists of one capsule orally, taken an hour
before food with a glass of water or milk (1stday,3rd day
&5th day)
5. No antibiotic should be taken during this period
6. Immunity starts 2-3 weeks after administration and lasts
for 3 years
7. A booster dose after 3 years
1.
Indications for Vaccination
1.Travelers going to endemic areas who will
be staying for a prolonged period of time,
2. Persons with intimate exposure to a
documented S. typhi carrier
3. Microbiology laboratory technologists who
work frequently with S. typhi
4.Immigrants
5. Military personnel
SIDE EFFECTS.
Injectable Typhim -Vi
The most common adverse reactions are injection site
pain, erythema, and induration, which almost always
resolve within 48 hours of vaccination. Occasional fever,
flu-like episodes, headache, tremor, abdominal pains,
vomiting, diarrhea, and cervical pains have been
reported.
Typhoral
Nausea, abdominal pain and cramps, vomiting, fever,
headache, and rash or urticaria may occur in some
instances but are rare.
International Classification of
Disease Codes for Typhoid fever
Disease
ICD-9
ICD-10
Typhoid & paratyphoid fevers 002
A01
Typhoid fever
A01.0
002.0
• *Bir Singh* Addl. Professor Centre for Community Medicine,
AIIMS, New Delhi-110 029, India
• Text book of Microbiology by CKJ Panicker
• K.PARK ( PREVENTIVE AND SOCIAL MEDICINE)
• Text book of community medicine (A.P.KULKARNI)
• TEXT OF COMMUNITY MEDICINE (T.BHASKAR RAO)
• www.cdc.gov/ncidod/dbmd/diseaseinfo/typhoidfever_
• www.netdoctor.co.uk/travel/diseases/typhoid.htm
• www.who.int/mediacentre/factsheets/
• en.wikipedia.org/wiki/Typhoid_fever –
• history1900s.about.com/od/1900s/a/typhoidmary.htm
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