PE31.12 | Typhoid — Summary & Reflection

KEY TAKEAWAYS

Typhoid fever at a glance:

• Aetiology: Salmonella Typhi — gram-negative rod, obligate human pathogen, faeco-oral transmission, no animal reservoir

• Clinical stages: Week 1 = stepladder fever + relative bradycardia + constipation; Week 2 = peak toxaemia + hepatosplenomegaly + rose spots + leucopenia; Week 3 = complication risk (perforation, haemorrhage)

• Gold standard diagnosis: Blood culture (60–80% sensitive, week 1 best); Widal test is UNRELIABLE in endemic areas (background titres, cross-reactions) — never use in isolation

• Key lab finding: Leucopenia (WBC 2,000–6,000/µL) with relative lymphocytosis supports diagnosis

• Treatment:
• Uncomplicated: azithromycin 20 mg/kg/day × 7 days (oral)
• Severe/complicated: ceftriaxone 75–100 mg/kg/day IV × 10–14 days
• MDR strains: avoid ampicillin, chloramphenicol, cotrimoxazole; use ceftriaxone or azithromycin

• Perforation: third week, sudden abdomen, free air on X-ray → emergency surgery

• Prevention: Typhoid Conjugate Vaccine (TCV, ≥6 months) in NIS + WASH practices

REFLECT

In India, millions of patients receive empirical treatment for typhoid based on a positive Widal test alone — a test widely acknowledged to be unreliable in endemic settings. Reflect on the tension between the ideal (blood culture gold standard) and the reality (unavailable or delayed in many settings). How would you counsel a family if you suspect typhoid clinically but cannot confirm it with blood culture? What does this scenario illustrate about the skill of clinical diagnosis — distinguishing likelihood from certainty — and the responsibility of the clinician to communicate uncertainty honestly while still making a decision?