Enteric fever is caused by the bacteria Salmonella typhi. It infects over 21 million people worldwide each year, mostly in Asia, Africa and Latin America, causing around 200,000 deaths. S. typhi is transmitted through the faeco-oral route. Clinical features include fever, gastrointestinal symptoms like abdominal pain and diarrhea, and complications can include intestinal bleeding, perforation and sepsis. Diagnosis involves blood and stool culture or serologic tests. Treatment is with antibiotics like fluoroquinolones or azithromycin for 10-14 days. Prevention involves boiling drinking water, hand washing and vaccination in endemic areas.

1. ENTERIC FEVER
John O Dickson
1st August, 2018

2. OUTLINE
 Epidemiology
 Pathogenesis
 Clinical features
 Investigation
 Management
 Complications
 Prevention
 Considerations

3. EPIDERMIOLOGY
• Organism – Salmonella typhi
• Infects only humans
• Patients excrete organisms in respiratory
secretions, Urine and Feces
• Convalescent and Chronic carrier often exist in
adult. (“Typhoid Mary” – Mary Mallon)

4. EPIDERMIOLOGY (Cont’d)
• According to the World Health Organization 2004
census, approximately 21.6 million cases occur per
year worldwide, mostly in Asia, Africa, and Latin
America, with 200,000 fatalities.
• Long survival of S. typhi in food facilitates transmission
• Transmission is usually through faeco-oral route
• Typhoid is endemic in Nigeria and it is a major cause
of morbidity and mortality for all ages

5. Salmonella Typhi
• Non-lactose fermenting, gram-negative bacillus and
has antigenic markers designated
– ‘O’ or somatic (cell wall) antigen
– ‘H’ or flagella antigen
– ‘V’ or virulence (or capsular) antigen .
• These antigen are also shared by other salmonella and
some coliforms, Hence in terms of diagnosis problems
can arise, causing false positive diagnosis.

6. PATHOGENESIS
• Following Ingestion, there is transient
bacteramia. This is followed by multiplication of
the bacterial in the reticulo-endothelial system
(eg. the Peyer’s patches), liver, and biliary
tracts.
• In the lymph nodes, the bacilli induce
hypertrophy, then ulceration and then necrosis.

7. PATHOGENESIS cont’d.....
• After incubation period of 7 -21 days, the
organism will invade the blood steam. The
larger the infecting dose of bacilli, the shorter
the incubation period
• Virulent typhoid bacilli inhibit the post
phagocytic oxidative metabolism of neutrophil,
unlike non-virulent typhoid strain and others
bacteria

8. PATHOGENESIS contd...........
• Having affinity for Peyer’s patches and the intestinal
lymphoid follicles.
• They may undergo necrosis, and ulcerations leading
to intestinal perforations or haemorrhage.
• This secondary septicaemia is usually prolonged
with the gall bladder being particularly susceptible.

9. CLINICAL FEATURES
• Varied features
• May mimic other illnesses
• High Index of suspicion
• High fever usually present, may be low grade or
absent in children that are malnourished
• Gastrointestinal symptoms
– anorexia, vomiting
– Abdominal pain, diarrhoea, constipation

10. CLINICAL FEATURES contd.........
– Presentation as perforation or haemorrhage.
– Jaundice, Hepatosplenomegaly
• Respiratory symptoms – e.g. bronchopneumonia
• CNS symptoms.
– lethargy, coma, convulsion, psychosis
• Macula-papular rash not seen in pigmented skins,
especially in blacks

11. INVESTIGATIONS
• 1. Blood culture
– isolation of salmonella typhi – Bone marrow
aspirate if antibiotics has already been taken.
Excluding relapsed blood culture not positive
after 2 weeks
• 2. Stool culture:
– positive from 2nd week in highly febrile patient
• 3. Widal test (lacks specificity and sensitivity)
– An agglutination test for antibodies to the ‘O’
and ‘H’ antigens.

12. INVESTIGATION contd........
• Useful if the range in the local population is known.
• Paired sera with a rising or falling titer is more useful
than a single determination
• Although titer of ‘O’ 1:500 or above usually
significant.
• Newer tests include immunoelectrophoresis
available in developed countries.

13. MANAGEMENT
• Adequate fluid and electrolyte balance
necessary
• Antipyretics and measures necessary
• Patient should be treated for 10-14day
• Cases with complication treat for 21 days.

14. MANAGEMENT contd...
Antibiotics therapy
• Chloramphenicol (1948-1970s) – antibiotic of choice in dose
of 50-100m/kg/24hrs in children and 25mg/kg/24hrs in
Neonates giving intravenously 6hrly
(NB: Relapse occur with chloramphenicol frequently and
associated with carrier states).
• Ampicillin or amoxycillin at 100mg/kg/24hrs
• Septrin (1980s)i.e. trimethoprin/sulphamethoxazole
– This has slower clinical response but no relapse or
chronicity
• OTHER MGT.
– Steroid can be use in cases of very ill patient who are toxic
looking.
– Surgical intervention reduces morbidity and mortality in
case of perforation or haemorrhage.

15. Antibiotics therapy Cont’d
• Fluoroquinolones – are the best drugs for treating
Typhoid (e.g ciprofloxacin).
• Alternatives include: Third generation
Cephalosporins (Ceftriaxone) and Azithromycin.
• OTHER MGT.
– Steroid can be use in cases of very ill patient
who are toxic looking. Hydrocortisone - 3mg/kg
over 30min, then 1mg/kg QDS X 8doses
– Surgical intervention reduces morbidity and
mortality in case of perforation or haemorrhage.

16. COMPLICATIONS
• Neuropsychiatric – delirium, irrational behavior,
convulsions, coma.
• Intestinal hemorrhage and perforation.
• Septic shock.
• Salmonella osteomyelitis.
• Typhoidal acute renal failure.
• Toxic myocarditis.
• DIC

17. CARRIER STATES
• NB: Convalescent carriers excrete the bacteria for periods
up to 3 months
• Patients still excreting past 3 months and up to 1 year meet
the definition of chronic carriers.
• Faecal carriage is more in those with gallbladder disease,
while urinary carriage is more in those with urinary
schistosomiasis and nephrolithiasis
• Gall bladder infection: 80% cured with cholecystectomy
with or without antibiotics.
• High dose ampicillin with probenecide for 4-6 wks also
effective.

18. PREVENTION
• Measures for individual protection are to kill S. typhi in
boiling water before drinking, iodination or
chlorination, care with uncooked or reheated food, and
immunization.
• Patients and convalescents with typhoid should be
advised to wash their hands after using the toilet and
before preparing food and to use separate towels.
• Primordial and primary prevention at the level of
government and community + Vaccination

19. THANKS FOR LISTENING!