A 22-year-old rice-field worker from Kerala presents with biphasic fever, conjunctival suffusion, calf muscle tenderness, and jaundice. Urinalysis shows haematuria and proteinuria. The MAT (microscopic agglutination test) titre is 1:400 for Leptospira icterohaemorrhagiae. The most appropriate treatment for this severe leptospirosis (Weil's disease) is:

• A Oral doxycycline 100 mg twice daily for 7 days
• B Oral azithromycin 500 mg daily for 5 days
• C IV penicillin G 1.5 million units 6-hourly for 7 days ✓
• D IV ceftriaxone 1 g once daily for 7 days

Explanation

Severe leptospirosis (Weil's disease — jaundice, renal failure, bleeding, pulmonary haemorrhage) requires IV antibiotics. IV penicillin G (1.5 MU 6-hourly for 7 days) or IV ceftriaxone (1 g/day) are the treatment options for severe disease. The MAT (using live antigen panels) is the gold standard reference serological test for leptospirosis, with titre ≥1:400 or fourfold rise in paired sera being diagnostic. Oral doxycycline is appropriate for mild leptospirosis prevention or mild disease. Azithromycin has limited data in severe disease.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.