NEET PG High-Yield: Typhoid Fever
A systemic enteric fever caused by Salmonella Typhi is historically significant for its high morbidity in endemic regions.
| Feature | Details |
|---|---|
| Causative Agent | Salmonella enterica serotype Typhi (Gram-negative bacillus). |
| Transmission | Feco-oral route (Contaminated water/food). |
| Incubation Period | 7–14 days (range: 3–60 days). |
Clinical Progression
- Week 1: “Step-ladder” fever pattern, bacteremia.
- Week 2: Abdominal symptoms, “Rose spots” on the trunk, splenomegaly.
- Week 3: Complications: Intestinal hemorrhage and ileal perforation.
High-Yield NEET PG Pearls:
- Gold Standard Diagnosis: Bone marrow culture (most sensitive), followed by blood culture (in 1st week).
- Widal Test: Detects O and H antibodies; requires a 4-fold rise in titer.
- Carrier State: Chronic carriage (usually in the gallbladder) occurs in 1–5% of cases.
- Treatment: Ceftriaxone or Azithromycin is preferred due to fluoroquinolone resistance.
- Prevention: Typhoid Conjugate Vaccine (TCV) is highly recommended for long-term immunity.