Early Diffuse Alveolar Hemorrhage Revealing Leptospirosis Without Multiorgan Failure: A Case Report and Literature Review.

Diffuse alveolar hemorrhage is a severe manifestation of leptospirosis, typically occurring in advanced stages of the disease and often associated with multiorgan failure. We report the case of a 44-year-old man without significant medical history admitted for acute febrile illness, hypotension, and respiratory symptoms occurring six days after initial symptom onset. Laboratory findings showed thrombocytopenia, elevated inflammatory markers, hepatic cytolysis, and mild acute kidney injury. Chest imaging demonstrated bilateral ground-glass opacities. Bronchoalveolar lavage (BAL) confirmed alveolar hemorrhage, revealing 1,300,000 red blood cells/mm³ with a neutrophil-predominant profile and negative microbiological investigations. Polymerase chain reaction testing confirmed leptospirosis. The patient was treated with intravenous ceftriaxone followed by oral amoxicillin, resulting in rapid clinical and biological improvement. This case highlights an atypical pulmonary presentation of leptospirosis without extra-respiratory involvement. Leptospirosis lung involvement should probably be considered in patients presenting with febrile illness, pulmonary infiltrates, and thrombocytopenia, in endemic settings, even without jaundice or severe renal impairment.