Enteric fever

Question 1

Enteric fever/ Typhoid Fever 🤒.

Organism

Pathogenesis

Answer 1

Organism :
Salmonella typhi & paratyphi (A,B,C) => G-ve bacilli 🦠

Pathogenesis:
- Transmitted by faceo-oral route
- From cases or carriers
-Bacteria proliferate in payer’s patches in small intestine -Followed by primary bacteremia
-Distributed to Reticuloendothelial system (RES) organs

Question 2

Clinical Presentation

Answer 2

1- Prodroma (1” week):
*Insidious onset ofheadache, prostration, anorexia and fever *Fever has a stepladder pattern; rising up to 39-40 co
* Coated tongue
* Relative bradycardia
* Diffuse abdominal pain
*Pea-soup diarrhea may occur early but constipation predominates later. * Rose spots :
- Erythematous maculopapular rash on the lower chest and abdomen - Appear in 25% of patients
- By the end of lst week
- Last 2-3 days
- Leaves slight brownish discoloration on healing 2-2nd week:
Fever becomes high and continuous
· Patient appear acutely ill , disoriented and lethargic (status typhosus)
*Tachycardia (due to myocarditis)
* Diffuse abdominal pain with splenomegaly and may be hepatomegaly 3- 3rd week:
*Gradualimprovementofgeneralcondition& declineoffever
*Complications may occur.

Question 3

Complications

Answer 3

Complications
-Neurologic: Encephalopathy , cerebral edema , Guillian Barre syndrome.

-Cardiac: Pan carditis and heart failure

• Pulmona_ry: Pneumonia , empyema
• Gastro intestinal: Intestinal perforation , intestinal hemorrhage
  Cholycystitis ( possible carrier state ) , hepatitis , splenic abscess

-Renal: Pyelonephritis , cystitis ( possible carrier state )

• Others: Osteomyelitis , septic arthritis.

Question 4

Investigations

Answer 4

Investigations .
1. CBC ~ anemia & leucopenia (toxic depression o f bone marrow). 2. In the 1st week ~ Blood culture is positive in 40-60% o f cases.
3. In the 2”d week onwards:
*Positive stool culture.
* Positive Widal test (titer> 11160) ~ Detect antibodies against 0 & H antigens
~ Never used alone to prove diagnosis
4. In the 3rd week ~ urine culture. 5. Recent investigations:
- Amplification o f S. Typhi specific antigens using PCR.
- Detect S. Typhi specific antigens using monoclonal antibodies -Culture ofbone marrow cells (not affected by prior use ofantibiotics)

Question 5

Treatment

Answer 5

Treatment 1· Cases:
- Bed rest & light diet
- Symptomatic treatment
- Treatment of complications.

Antibiotics

Question 6

Prevention

Prognosis

Answer 6

2· Prevention:
-Food & water hygiene
-Vaccine~ Ty2la m:Vi capsular conjugate vaccine (TAB vaccine is obsolete)
Prognosis
* With early antibiotic therapy; mortality is less than 1%
* Relapse occur 1-3 weeks later in 10-20% despite appropriate antibiotics