Severe leptospirosis — DTM&H MCQ

Correct answer: D — Intravenous ceftriaxone or benzylpenicillin with organ support

The correct answer is D, intravenous ceftriaxone or benzylpenicillin with organ support. This patient has Weil's disease, the severe icteric form of leptospirosis, signalled by the occupational exposure (rice farming, flooding), conjunctival suffusion, myalgia (calf tenderness), jaundice, acute kidney injury (creatinine 280 micromol/L, oliguria) and thrombocytopenia. Severe leptospirosis with multi-organ involvement requires parenteral antimicrobial therapy plus supportive care (renal replacement, fluid and haemodynamic support) rather than oral therapy, since gut absorption and clinical status cannot be relied upon once organ failure is established. Ceftriaxone and benzylpenicillin both have proven efficacy against Leptospira and remain first-line parenteral options in severe disease, with treatment started empirically given the high mortality of untreated Weil's disease. Why the other options are wrong: B. Oral oseltamivir and home isolation: this treats influenza, which does not cause jaundice, renal failure or conjunctival suffusion in this pattern; home isolation is inappropriate for a patient with organ failure needing admission. A. Praziquantel as a single dose: this is the treatment for schistosomiasis or other fluke infections, which do not produce this acute febrile illness with conjunctival suffusion and rapid renal and hepatic dysfunction after flooding. C. Fluconazole induction therapy: an antifungal used for conditions like cryptococcal meningitis, irrelevant to a bacterial spirochaetal infection with this clinical picture. E. Atovaquone-proguanil treatment dose: this treats malaria, but the specific combination of conjunctival suffusion, calf tenderness and flood-water exposure points away from malaria towards leptospirosis, and this dose would not address the renal failure or thrombocytopenia mechanism here. Key point: conjunctival suffusion plus calf tenderness and jaundice after freshwater or flood exposure is the classic triad for leptospirosis, and severe (icteric) disease with renal failure mandates IV beta-lactam therapy and organ support, not oral treatment.

Reference: UK Health Security Agency (UKHSA), Doxycycline versus azithromycin for treatment of leptospirosis and scrub typhus (research summary); severe leptospirosis (Weil's disease) management with parenteral penicillin or ceftriaxone plus organ support is consistent with WHO leptospirosis guidance and Manson's Tropical Diseases. https://researchportal.ukhsa.gov.uk/en/publications/doxycycline-versus-azithromycin-for-treatment-of-leptospirosis-an/