2. TYPHOID
• Typhoid fever is due to systemic
infection mainly by Salmonella
typhi
• Salmonella typhi infection is
found only in men
3. • The disease is clinically
characterized by a typical
continuous fever for 2-3 weeks,
with relative bradycardia with
involvement of lymphoid tissues
and considerable constitutional
symptoms
4. • The term “ENTERIC FEVER”
includes both typhoid and para
typhoid fevers
• The disease may occur
sporadically, epidemically or
endemically
8. • S.typhi has three main antigens :
O, H & Vi and a number of phage
types
• S.typhi survives intra cellularly in
the tissues of various organs
9. • It is readily killed by drying,
pasteurization and common
disinfectants
• The factors which influence the
onset of typhoid fever in man
are the infecting dose and
virulence of the organism
10. • RESERVOIR OF INFECTION: Man
is the only known reservoir of
infection (via cases & carriers)
• CASES: A case is infectious as
long as bacilli appears in stools
or urine
11. • CARRIERS: The carriers may be
temporary (incubatory,
convalescent) or chronic
• Convalescent carriers excrete
bacilli for 6-8 weeks (after which
their numbers diminish rapidly
by the end of three months)
12. • Persons who excrete bacilli for
more than one year are after
clinical attack are called chronic
carriers
13. • In most chronic carriers the
bacilli exists in gall bladder and
in the billiary tract. A chronic
carrier may excrete the bacili for
several years (may be as long as
50 years)
14. • A famous case of “Typhoid
Mary” who gave raise to 1300
cases in her life time is an
example for a chronic carrier
state
• Faecal carriers are more common
than urinary carriers
15.
16. SOURCE OF INFECTION
• The primary sources of infection
are faeces and urine of cases or
carriers
• The secondary sources include
contaminated water, food, fingers
and flies
17. HOST FACTORS
• AGE: Typhoid fever may occur at
any age
• GENDER: Males are more
affected than females
18. • IMMUNITY: All ages are
susceptible to infection
• The host factors that contributes
to resistance to the bacilli are
gastric acidity & local intestinal
immunity
19. ENVIRONMENTAL & SOCIAL
FACTORS
• Enteric fevers are observed all
throughout the year
• The peak incidence is reported
during July-September
20. • Vegetables grown in sewage
farmlands or washed in
contaminated water are positive
health hazard
21. • Typhoid bacilli grow rapidly in
milk without altering in taste or
appearance in anyway, in which
case ingestion of such raw milk
poses a threat to the consumer
22. • These factors are compounded
by such social factors as
pollution of drinking water
supplies, open air defecation and
urination, low standards of food
and personal hygiene and health
ignorance
23. • Therefore typhoid fever may be
regarded as an index of general
sanitation in any country
24. INCUBATION PERIOD
• Usually 10-14 days
• But the it can be as short as 3
days or as long as 3 weeks,
depending on the dose of bacilli
ingested
25. MODE OF TRANSMISSION
• Typhoid fever is transmitted via
the faecal-oral route or urine-
oral routes
26. • This may take place directly
through soiled hands
contaminated with faeces or
urine of cases or carriers or
indirectly by the ingestion of
contaminated water, milk, food
or through flies
28. CLINICAL FEATURES
• The onset is insidious, but in
children may be abrupt with
chills and high fever
29. • During the prodromal stage ,
there is malaise, headache,
cough and sore throat often with
abdominal pain and constipation
• The fever ascends in step ladder
fashion
30. • 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 the early stages or
“pea soup diarrhoea”
31. • There is marked abdominal
distension
• There is leukopenia and blood,
urine and stool culture is positive
for salmonella
32. • If there are no complications the
patient’s condition improves
over 7-10 days
• However relapse may occur for
up to 2 weeks after termination
of therapy
33. • During early phase, physical
findings are few
• Later splenomegaly, abdominal
distension and tenderness,
relative bradycardia, dicrotic
pulse and ocassionaly
meningsmus appear
34. • The rash (rose spots)commonly
appear during the second week of
the disease
• The individual spot , found
principally on the trunk, is a pink
papule 2-3 mm in diameter that
fades on pressure. It disappears in
in 3-4 days
36. • Serious complication occur in up
to 10 percent of patients
(especially those who have been
ill for longer than 2 weeks and
who have not received proper
treatment)
37. • Intestinal haemorrhage is
manifested by a sudden drop in
temperature and signs of shock,
followed by dark or fresh blood
in the stool
• Intestinal perforation is most
likely to occur during the third
week
38. • Less frequent complications are
urinary retention, pneumonia,
thrombophlebitis, myocarditis,
psychosis, cholecystitis, nephritis
and oeteomyelitis
39. LABORATORY DIAGNOSIS
• MICROBIOLOGICAL PROCEDURES
The definitive diagnosis of
typhoid fever depends on the
isolation of the bacilli from
blood, bone marrow and stools.
Blood culture is the mainstay of
diagnosis of this disease
40. SEROLOGICAL PROCEDURE
• Felix-Widal test measures
agglutinating antibody levels
against O & H antigens
• Usually “O” antibodies appear
on day 6-8 and “H” antibodies on
day 10-12 after the onset of
disease
41. • The test is usually performed on
an acute serum (at first contact
with the patient)
• The test has moderate sensitivity
and specificity
42. • It can be negative up to 30% of
culture – proven case of typhoid
fever
• This may be because of prior
antibiotic therapy, that has
blunted the antibody response
43. NEW DIAGNOSTIC TESTS
• The IDL tubex test can detect
specific IgM antibodies in
samples to S. Typhi
liposaccharide (LPS) antigen and
the staining of bound antibodies
by anti-human IgM antibody
conjugated to colloidal dye
particles
45. CONTROL OF TYPHOID
FEVER
• The control or elimination of the
typhoid fever is well within the
scope of modern public health
46. • There are generally three lines of
defence against typhoid fever:
• 1. Control of reservoir
• 2. Control of sanitation
• 3. Immunization
47. CONTROL OF RESERVOIR
• The usual methods of control of
reservoir are their identification,
isolation, treatment &
disinfection
48. • CASES: EARLY DIAGNOSIS –This is
of vital importance as the early
symptoms are non-specific
• Culture of blood and stools are
important investigations in the
diagnosis of cases
49. NOTIFICATION:
Notification must be done in areas
where it is mandatory
ISOLATION:
Since typhoid is an infectious
disease the cases are to be
transferred to hospital
50. • As a rule cases should be
isolated till three
bacteriologically negative
stools and urine reports are
obtained on three separate
days
53. • They are relatively inexpensive
and well tolerated and more
reliably and effectively than
chloremphenicol, ampicillin,
amoxicillin, and trimethoprim &
sulphamethoxazole
54. • Patients seriously ill and
profoundly toxic should be given
Inj of hydrocortisone 100 mg daily
for 3-4 days
• DISINFECTION: stools and urine
are the sole sources f infection.
They should be received in in
closed containers and disinfected
with 5% cresol for at least 2 hours
55. • All soiled clothes and linen
should be soaked in a solution
of 2% chlorine and be stream
sterilized
• Doctors and nurses should
disinfect their hands
56. FOLLOW UP
• Examination of stools and urine
should be should be done for
S.typhi 3-4 months after
discharge and again 12 months
to prevent development of
carrier state
57. CARRIERS:
• Since carriers are the ultimate
source of infection, their
identification and treatment is
one of the most radical ways of
controlling typhoid fever
• The following are the measures
recommended:
58. • IDENTIFICATION: Carriers are
identified by cultural and serological
examinations. Duodenal drainage
establishes the presence of
salmonella in the biliary tract of
carriers
• The antibodies are present in about
80% of chronic carriers
59. TREATMENT OF CARRIERS:
• The carriers should be given an
intensive course of ampicillin or
amoxycillin (4-6 g a day)
together with probenecid
(2g/day) for 6 weeks
60.
61. • These drugs are concentrated in
the bile and may achieve
eradication
• Chloromycetin is considered
worthless for clearing the carrier
state
63. • Urinary carriers are eassy to treat,
but refractory cases may need
nephrectomy when one kidney is
damaged and the other is healthy
• SURVEILLANCE: The carriers
should be kept under surveillance.
They should be prevented from
handling food, milk or water for
others
64. HEALTH EDUCATION
• Health education regarding
washing of hands with soap after
defecations or urination and
before preparing food is an
essential element
65. • In short, the management of
carriers continues to be an
unsolved problem
• This is the crux of the problem,
in the elimination of typhoid
66. CONTROL OF SANITATION
• Protection and purification of
drinking water supplies,
improvement of basic sanitation
and promotion of food hygiene
are essential measures to
interrupt transmission of typhoid
fever
67. IMMUNIZATION
• Immunization is a
complimentary approach in the
prevention of typhoid
• It yields the highest benefit to
the money spent
68. • Immunization against typhoid
does not give 100% protection,
but it definitely lowers both the
incidence and seriousness of the
infection
• It can be given at any age
upwards 2 years
69. • Immunization is recommended
to those who live in endemic
areas, house hold contacts and
groups at risk of infection such
as school children and hospital
staff, travellers proceeding to
endemic areas and those
attending melas and yatras
70. ANTI TYPHOID VACCINES
• Two vaccines are available:
1. Vi polyssaccharide vaccine
2. The Type 21a vaccine
71.
72. Vi POLYSSACCHARIDE VACCINE
• The vaccine is composed of
purified Vi capsular
polysaccharide from the Ty2 S
typhi strain and elicits a T-cell
independent IgG response that is
not boosted by additional doses
73. • The vaccine is administered sub
cutaneously or intra muscularly .
The target value of each single
human dose is about 25 micro
gram of antigen
• The vaccine is stable for 6 months
at 370 C and for 2 years at 220 C
74. • The recommended storage
temperature is 2-8oC.The Vi vaccine
does not elicit adequate immune
responses in children aged less than
2 yrs
• Only one dose is required and the
vaccine confers protection after 7
days of vaccination
75. • Tomaintain protection
revaccination is recommended
every three years.
• The vaccine can be co-
administered with other vaccines
(such as yellow fever, and
hepatitis A and with routine
childhood vaccinations)
76. • No serious adverse events and
minimum of local effects are
associated with Vi vaccination
• There are no contra indications
to the vaccine other than
previous hypersensitivity
reaction to vaccine components
77. THE TYPE 21a VACCINE
• Is an orally administered live
attenuated Ty2 strain of S.typhi.
The lyophilized vaccine is
available as enteric coated
capsules
79. • The vaccine has to be stored at
2-80C, it retains potency for
approximately 14 days at 250 C
• The capsules are licensed for use
in individuals aged above 5 yrs
80. • The vaccine is administered
every other day (on 3 and 5 day)
a 3-dose regimen is
recommended
• Protective immunity is achieved
7 days after the last dose
81. • The recommendation is to
repeat the series every 3 years
for people living in endemic
areas and every year for
individuals travelling from non
endemic to endemic areas
