A cog in the Weil: A case report of severe leptospirosis

The nonspecific presentation of leptospirosis and delays in serologic confirmation often make its diagnosis challenging. The presence of comorbidities or potential drug toxicities, which can mimic or obscure clinical findings, further adds to this diagnostic difficulty. Here, we present the case of a 46-year-old male with well-controlled HIV infection on antiretroviral therapy, who presented with a four-day history of fever, malaise, and jaundice. The patient is a pilot with recent travel to the United Kingdom and prior travel throughout North America, Central America, and the Caribbean. On admission, he was febrile and tachycardic, with laboratory studies demonstrating elevated creatinine and transaminases. Broad-spectrum antibiotics were initiated and subsequently de-escalated to doxycycline, while antiretroviral therapy was temporarily held. A renal biopsy demonstrated acute tubulointerstitial nephritis. The patient improved clinically with doxycycline, with normalization of liver and kidney function by the time of discharge. Post-discharge serologic testing returned positive for Leptospira IgM antibodies, confirming the diagnosis of Weil's disease. This case underscores the diagnostic challenges of leptospirosis, particularly in patients without clear exposure histories, and highlights the importance of early empiric therapy when clinical suspicion is high.