Leptospirosis

Leptospirosis is an infectious disease caused by pathogenic spirochete bacteria of the genus Leptospira. It is a zoonotic illness, meaning it is transmitted from animals to humans, typically through contact with water, soil, or food contaminated with the urine of infected animals such as rodents, dogs, cattle, and pigs. The bacteria can enter the body through cuts or abrasions in the skin, through mucous membranes (eyes, nose, mouth), or through ingestion of contaminated water. Leptospirosis is also known as Weil disease (in its severe form), canicola fever, swamp fever, mud fever, or hemorrhagic jaundice. The disease affects multiple body systems and has a wide clinical spectrum ranging from mild, self-limiting febrile illness to severe, life-threatening multiorgan dysfunction. Common symptoms include high fever, severe headache, muscle pain (particularly in the calves and lower back), chills, conjunctival suffusion (redness of the eyes without discharge), nausea, vomiting, diarrhea, and skin rash. The illness typically presents in two phases: an initial acute septicemic phase lasting about a week, followed by an immune phase. In severe cases (Weil disease, corresponding to ICD-10 code A27.0), patients may develop jaundice, renal failure, hemorrhagic manifestations, pulmonary hemorrhage, meningitis, and cardiovascular collapse, which can be fatal if untreated. Treatment involves antibiotic therapy, with doxycycline and penicillin being the most commonly used agents for mild and severe cases, respectively. Intravenous penicillin G or ceftriaxone is recommended for severe leptospirosis. Supportive care, including fluid management, dialysis for renal failure, and mechanical ventilation for pulmonary complications, may be necessary in severe cases. Early diagnosis and prompt antibiotic treatment significantly improve outcomes. Doxycycline may also be used as prophylaxis in high-risk exposure settings. Leptospirosis is most prevalent in tropical and subtropical regions, particularly during rainy seasons and flooding events, and is considered one of the most widespread zoonotic diseases globally.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Leptospirosis