Leptospirosis — DTM&H MCQ

Correct answer: E — Doxycycline or intravenous beta-lactam according to severity

The correct answer is E, doxycycline or intravenous beta-lactam according to severity. The vignette describes leptospirosis: occupational sewer exposure to rat-contaminated floodwater in an endemic setting (Manila), fever, myalgia with classic calf tenderness, conjunctival suffusion, and renal and hepatic impairment (raised creatinine and bilirubin) suggesting evolving Weil's disease. Mild to moderate leptospirosis is treated with oral doxycycline, while severe disease with organ dysfunction (renal failure, jaundice, pulmonary haemorrhage) requires parenteral therapy with a beta-lactam such as benzylpenicillin or a third-generation cephalosporin (ceftriaxone or cefotaxime). This severity-adapted antibiotic strategy is standard because Leptospira remains sensitive to both drug classes and early treatment reduces duration and complications of illness. Why the other options are wrong: D. Fluconazole: this is an antifungal with no activity against Leptospira, a spirochaete bacterium; there is no fungal element to this presentation. A. Praziquantel: this treats trematode and cestode infections (schistosomiasis, tapeworms); it has no role in a bacterial spirochaetal illness and does not address the acute renal and hepatic picture described. B. Chloroquine: this is an antimalarial; while fever after tropical exposure can suggest malaria, the combination of conjunctival suffusion, calf tenderness and occupational floodwater exposure points specifically away from malaria towards leptospirosis, and chloroquine has no antibacterial action. C. Albendazole: this is an anthelmintic used for soil-transmitted helminths and some tissue parasites; it has no effect on Leptospira and does not fit the clinical syndrome. Key point: conjunctival suffusion plus calf tenderness after floodwater or sewer exposure is the classic clue for leptospirosis, treated with doxycycline for mild disease or intravenous benzylpenicillin/ceftriaxone once severity (renal or hepatic dysfunction) develops.

Reference: Patient.info (Professional Reference, UK): Leptospirosis (Weil's Disease), Doctor - first-choice antibiotic is oral doxycycline or azithromycin for non-critical adults, with severe disease requiring parenteral therapy; https://patient.info/doctor/infectious-disease/leptospirosis-weils-disease