typhoid fever

1. TYPHOID FEVER

2. TYPHOID FEVER
Introduction
Problem statement
Agent factors
Host factors
Environmental factors
Incubation period
Clinical features
Diagnosis
Control and prevention

3. Introduction
Typhoid fever is the result of systemic infection mainly by
S.typhi found only in man.
Clinically
continuous fever for 3 or 4 weeks,
relative bradycardia with involvement of lymphoid
tissues and considerable constitutional symptoms.
The term “enteric fever” includes both typhoid and
paratyphoid fevers.

4. Problem Statement
World :-
Occurs in all countries- water supplies and sanitation are
sub-standard.
Affects- 6 million - worldwide with 600,000 deaths a year.
80% of cases & deaths - Asia, Africa & Latin America.
Close to eradication in UK, with approximately 1 case per
1,000,000 population.

6. Problem Statement
INDIA :-
Typhoid is endemic in India.
Study in an urban slum showed 1% of children up to
17yrs of age suffer from typhoid every year.
1995- there were 3,29,499 cases & 672 deaths from
typhoid.
2013- 1.53M cases & 161 deaths

7. Agent Factors

8. AGENT
S. typhi is the major cause of enteric fever.
S. paraA and S.paraB are relatively infrequent.
S. typhi has three major antigens - O, H and Vi antigens.
S. typhi survives intracellularly in various organs.
It is readily killed by drying, pasteurisation & common
disinfectants.

9. RESERVOIR OF INFECTION
Man is the only known reservoir of infection, viz cases and
carriers.
A case is infectious as long as bacilli are in stools or urine.
Carriers :-
They may be temporary (incubatory or convalescent) or
chronic.
Convalescent carriers excrete bacilli for 6-8 wks.
Chronic carriers excrete for more than 1yr.
Eg: Typhoid Mary, who gave rise to 1300 cases in her
lifetime.

10. SOURCE OF INFECTION
Primary sources of infection are faeces and urine of
cases and carriers.
Secondary sources are contaminated water, food,
fingers and flies.

11. Host Factors

12. Age :- It may occur at any age. Highest incidence- 5-19yrs
Sex :- More cases - males, probably as a result of increased
exposure to infection. Carrier state - more in females.
Immunity :- Antibody may be stimulated by infection or by
immunization.
However the antibody to somatic antigen (O) is usually
higher in patient with disease & antibody to flagellar
antigen (H) is more in immunized individuals.
Host factors that contribute to resistance against S. typhi
are gastric acidity and local intestinal immunity.

13. Environmental factors

14.  Present throughout the year, peak inci. - July-September.
 Survive for over a month in ice & ice-cream.
 Up to 70 days in soil irrigated with sewage under moist
winter conditions.
 They may also survive and multiply in milk, vegetables and
food.
 Social factors such as pollution of drinking water supplies,
open air defecation and urination, low standards of food
personal hygiene and health ignorance.

15.  Incubation Period :-
It is usually 10-14 days. It may be as short as 3 days
or as long as 3 weeks depending on the dose of
bacilli ingested.

16. Modes of transmission
Faeces
and
urine
from cases
and
carriers
Water
Soil
Flies
Fingers
Foods
raw
or
cooked
Mouths
of
well
persons

17. Clinical Features

18. Onset :- Usually insidious, but in children may be abrupt
with chills & rigor.
Prodromal stage :- There is malaise, headache, cough &
sore throat often with abdominal pain & constipation.
Fever ascends in a step ladder fashion.
After about 7-10 days, fever reaches plateau, patient is
toxic, exhausted & often prostrated.
Marked constipation, especially in early stage or
“pea-soup” diarrhoea, abdominal distention.
If no complications, recovery in 7-10 days.

19. Diagnosis
Physical findings:
Splenomegaly
Abdominal distention & tenderness.
Relative bradycardia
Dicrotic pulse
Rose spots

20. Complications
Occur in about 30% of untreated cases & account for
75% of all deaths due to typhoid fever.
Intestinal hemorrhage
Intestinal perforation
Less frequent are :
Urinary retention
Pneumonia
Thrombophlebitis
Myocarditis
Psychosis, nephritis, osteomyelitis

21. Control & Prevention

22. Control of typhoid fever can be done by
1. Control of reservoir
2. Control of sanitation
3. Immunization

23. Control of reservoir
It consists of
Cases
Carriers

24. Cases
Early diagnosis : Culture of blood & stools are important as
the symptoms are non-specific.
Notification : This should be done where such notification is
mandatory.
Isolation : Cases are better transferred to a hospital for
better treatment, as well as to prevent the spread of
infection.

25. Treatment
 Patients seriously ill – inj. of hydrocortisone 100mg/d 3-4d

26.  Disinfection :
o Stools & urine are disinfected with
5% cresol for 2hrs.
o Soiled clothes & linen are disinfected with 2% chlorine
& steam sterilized.
o Nurses & doctors must disinfect their hands.
 Follow up :
o Examination of stools & urine must be done for S.typhi
3-4 months after discharge of patient & again after
12months.

27. Carriers
 Identification :
 Identified by culture & serological examinations
 Duodenal drainage establishes presence of
salmonella in biliary tract of carriers.
 Vi antibodies are present in 80% of chronic carriers.
 Treatment :
 An intensive course of ampicillin (4-6g a day) together
with probenecid ( 2g/day) for 6 wks.

28.  Surgery :
 Cholecystectomy with concomitant ampicillin therapy is
regarded as most successful treatment for carriers with
success rate of 80%.
 Urinary carriers are easy to treat, but refractory cases may
need nephrectomy when one kidney is damaged and the
other healthy.
 Surveillance :
 Carriers should be prevented from handling food, milk or
water for others.
 Health education :
 Health education regarding washing of hands with soap,
after defecation & urination, before preparing food is an
essential element.

29. Control of sanitation
 Protection & purification of drinking water
supplies.
 Improvement of basic sanitation.
 Promotion of food hygiene.

30. Immunization
 Immunization is recommended to
o Those living in endemic regions
o Household contacts
o Groups at risk of infection, such as hospital staff
& school children
o Travellers proceeding to endemic areas
o Those attending melas & yatras

31. Anti-typhoid vaccines currently available in India are
Monovalent anti-typhoid vaccine : agar grown, heat
killed & phenol preserved vaccine, contains 1,000 million
of S. typhi per ml.
Bivalent anti-typhoid vaccine : contains 1,000 million &
500 million of S. typhi & S. paratyphi A, respectively, per
ml.
TAB vaccine : contains S. typhi (1,000 million), S.
paratyphi A (500-750 million), S. paratyphi B (500-750
million) organisms per ml.

32. Dosage & route of administration
 Primary immunization :
 2doses ( each of 0.5ml), given subcutaneously, at an
interval of 4-6 wks.
 Children between 1-10yrs are given smaller doses
(0.25ml).
 Immunity develops in 10-21 days & lasts for 3yrs.
 Booster doses :
 They are recommended every 3yrs.
 Storage :
 stored in a refrigerator at 20-40C.

33. Typhoral
 It is live oral Ty 21a vaccine
 Contains about 109 S. typhi strain Ty 21a.
 Indicated for immunization of adults and children more
than 6yrs of age.
 1 capsule is administered on days 1,3,5, 1hr before a
meal with lukewarm water or milk.
 Protection commences 2wks later & lasts for 3yrs.
 Booster doses are recommended once in 3yrs.