A 28-year-old man from Delhi presents with a 10-day history of high-grade fever, headache, and abdominal discomfort. He returned from a visit to a rural area 2 weeks ago where he consumed street food and untreated water. On examination, he is febrile (39.5°C), has a relative bradycardia, and a faint rose-colored rash on the trunk. Blood culture is positive for a Gram-negative rod. Widal test shows O antigen titre of 1:320 and H antigen titre of 1:160. What is the most appropriate next step in management?

Explanation

## Diagnosis and Management of Enteric Fever ### Clinical Presentation Recognition **Key Point:** The constellation of prolonged fever, headache, rose spots (faint maculopapular rash on trunk), relative bradycardia, and positive blood culture in a patient with recent travel to endemic area with poor sanitation is pathognomonic for **Salmonella typhi enteric fever (typhoid).** ### Widal Test Interpretation | Antigen | Acute Infection | Chronic Carrier | Past Infection | |---------|-----------------|-----------------|----------------| | **O antigen (IgM)** | ≥1:320 | Negative | Low titre | | **H antigen (IgG)** | ≥1:160 | Positive | Elevated | | **Both elevated** | Active infection | — | — | **High-Yield:** O antigen ≥1:320 + H antigen ≥1:160 in a febrile patient = **active enteric fever** until proven otherwise. Blood culture positivity confirms diagnosis. ### Current Antibiotic Therapy Guidelines **Key Point:** In India, with increasing fluoroquinolone and cephalosporin-resistant S. typhi (CRST), the **WHO and Indian guidelines (2023)** recommend: 1. **First-line:** Ceftriaxone 2 g IV/IM 12-hourly (or cefixime 400 mg PO BD for uncomplicated cases) 2. **Alternative:** Fluoroquinolone (levofloxacin 750 mg daily) **only if susceptibility confirmed** 3. **Avoid:** Chloramphenicol (outdated, poor CNS penetration, bone marrow toxicity) 4. **Avoid:** Empiric fluoroquinolone in endemic areas due to resistance **Clinical Pearl:** Blood culture positivity is the gold standard diagnosis; Widal is supportive. Start cephalosporin immediately after blood culture is drawn — do NOT wait for susceptibility results in a febrile patient. ### Why Ceftriaxone is Correct - Excellent tissue penetration (including CNS) - Covers resistant S. typhi strains prevalent in India - Rapid defervescence (typically within 3–5 days) - Safe in pregnancy and children - No need to wait for susceptibility — empiric choice in endemic areas ### Duration and Monitoring - **Uncomplicated:** 7–14 days IV therapy - **Complicated (perforation, encephalitis):** 14–21 days - **Defervescence:** Expected by day 3–5; if fever persists, consider complications (perforation, abscess, relapse) **Mnemonic: CEFT-FIRST** = **C**ephalosporin **E**mpiric, **F**luoroquinolone **T**est-guided, **F**irst-line in **I**ndia, **R**esistance-aware, **S**tart **T**herapy immediately