A field presentation

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!