Typhoid fever

This ppt contains all the information about the epidemiology of typhoid fever. It is useful for students of the medical field learning Preventive and social medicine, Swasthavritta (Ayurved), and everyone who is interested in knowing about it.

1. Typhoid fever
Dr. ShubhangiS. Kshirsagar
Assistant professor
Department of Swasthavritta& Yoga
[email protected]

2. Typhoid fever
▪Typhoidfeveristheresultofsystemicinfection
mainlybyS.typhifoundonlyinman.
▪Thediseaseisclinicallycharacterizedbya
typicalcontinuousfeverfor3to4weeks
relativebradycardiawithinvolvementof
lymphoid tissue and considerable
constitutionalsymptoms.
▪Theterm“entericfever”includesbothtyphoid
andparatyphoidfevers.
▪Itmayoccursporadically,epidemicallyor
endemically

3. Agent factors
1.Agent
▪S.typhiisthemajorcauseofentericfever.
▪S.paraAandS.paraBarerelatively
infrequent
▪S.TyphihasthreemainantigensO,HandVi
andanumberofphagetypes(atleast80).
▪S.typhisurvivesintracellularlyinthetissuesof
variousorgans.
▪Itisreadilykilledbydrying,pasteurization,and
commondisinfectants.

4. 2. Reservoir of infection
Human is the only reservoir of infection.
a.Cases
▪The case may be
mild, missed or
severe.
▪A case (or
carrier) is
infectious as
long as bacilli
appear in stools
or urine.
b. Carriers
▪Temporary
(incubatory,
convalescent) or
chronic.
▪Convalescent carriers
excrete the bacilli for 6
to 8 weeks.
▪Chronic carrier
excretes basillifor
more than a year.

6. 3. Source of infection
▪The primary sources of infection are faeces
and urine of cases or carriers
▪The secondary sources contaminated water,
food, fingers and flies.

7. Host factors
1.Age –Highest incidence in the 5-19 yrs of age
group.
2.Sex –More in males than female, but carrier rate
more in females
3. Immunity –
▪All ages are susceptible to infection.
▪Antibody may be stimulated by the infection or by
immunization.
▪The antibody to the somatic antigen (O) is usually
higher in the patient with the disease and the
antibody to the flagellarantigen (H) is usually
higher in immunized individuals.
▪S. typhibeing an intracellular organism, cell-

8. Environmental factors
▪Peak incidence in July –September
▪Outside the human body, bacilli found in water, ice, food,
milk and soil
✓Water –survive for 7 days, but do not multiply
✓Ice & icecream–survive for over a month
✓Soil –survive for upto70 days in soil irrigated with
sewage
✓Food –multiply & survive for sometime
✓Milk –grows rapidly
▪Vegetable grows in sewage farm
▪Social factors –pollution of drinking water supplies, open
air defecation and urination, low standards of food and
personal hygiene and health ignorance.
▪Typhoid fever may therefore be regarded as an index of
general sanitation in any country.

9. Incubation period
▪Usually 10-14 days.
▪But it may be as short as 3 days or as long
as three weeks depending upon the dose of
the bacilli ingested.

10. Mode of transmission
▪Typhoidfeveristransmittedviathefaecal-
oralrouteorurine-oralroutes.
▪Thismaytakeplacedirectlythroughsoiled
handscontaminatedwithfaecesorurineof
casesorcarriers,orindirectlybythe
ingestionofcontaminatedwater,milkand/or
food, or through flies.

11. Clinical features
▪Malaise, headache, cough and sore throat,
often with abdominal pain and constipation.
▪The fever ascends in a step-ladder fashion.
▪After about 7-10 days, the fever reaches a
plateau and the patient looks toxic,
appearing exhausted and often prostrated.
▪There may be marked constipation,
especially in early stage or pea soup
diarrhoea.

12. ▪Later,splenomegaly,abdominaldistension
andtenderness,relativebradycardia,dicrotic
pulse,andoccasionallymeningismus
appear.
▪Therash(rosespots)commonlyappears
duringthesecondweekofdisease.
▪Theindividualspot,foundprincipallyonthe
trunk,isapinkpapule2-3mmindiameter
thatfadesonpressure.Itdisappearsin3-4
days

13. ▪Seriouscomplicationsoccurinupto10per
cent of
typhoidfeverpatients,especiallyinthose
whohavebeenilllongerthan2weeks,and
whohavenotreceivedpropertreatment.
▪Intestinalhaemorrhageismanifestedbya
sudden
dropintemperatureandsignsofshock,
followedbydarkorfreshbloodinthestool.
▪Intestinalperforationismostlikelytooccur
duringthethirdweek.
▪Lessfrequentcomplicationsareurinary
retention,pneumonia, thrombophlebitis,
myocarditis,psychosis, cholecystitis,

14. Laboratory diagnosis
1.Microbiological procedure –blood culture
2.Serological procedure –Felix-Widaltest
3.New diagnostic tests –
▪IDL tubex
▪Typhidot
▪Typhidot-M
▪Typhidotrapid
▪IgMdipstick test

15. Control of typhoid fever
1.Control of reservoir
2.Control of sanitation
3.Immunization

16. Control of reservoir
a. Case
1.Earlydiagnosisbycultureofblood&stool
2.Notification–whereitismandatory
3.Isolation-till3bacteriologicallynegativestool
&urinereports
4.Treatment–fluoroquinolonesdrugofchoice
5.Disinfectionofstool&urineby5%cresolfor2
hoursandsoiledclothsby2%chlorine.
6.Follow-upexaminationofstoolsandurine
shouldbedoneforS.typhi3to4monthsafter
dischargeofthepatientandagainafter12
monthstopreventthedevelopmentofthe
carrier state.

17. b. Carriers
1.Identificationbyculturalandserological
exam
2.Treatment–intensivecourseofampicillin
oramoxycillinwithprobenecidfor6weeks
3.Surgery–Chlolecystectomyifneeded
4.KeptunderSurveillance,Theyshouldbe
preventedfromhandlingfood,milkorwater
forothers.
5.Healtheducationregardingwashingof
handswithsoap,afterdefecationor
urination,andbeforepreparingfoodisan
essential element.

18. 2. Control of sanitation
▪Essential measures to interrupt transmission
of typhoid fever are –
a.Protection and purification of drinking water
supplies
b.Improvement of basic sanitation
c.Promotion of food hygiene

19. 3. Immunization
▪Immunization is recommended to -
✓Those living in endemic areas
✓Household contacts
✓Groups at risk of infection such as school
children and hospital staff
✓Travelers proceeding to endemic areas
✓Those attending melasand yatras.
▪Anti-typhoid vaccine -
1.Vi polysaccharide vaccine
2.Ty 21 a vaccine

20. Anti-typhoid vaccines
Vi polysaccharide
vaccine
Ty 21 a vaccine
Subcutaneous /IM Oral
Not for <2yrs Not for <3yrs
1 dose Alternate day 1-3-5-7
Protection after 7 days Protection after 7 days
Revaccination every
3yrs
Revaccination every
3yrs
Liveattenuated

24. Thank You !