[Leptospirosis].

Leptospirosis. Leptospirosis is the first worldwide anthropozoonosis with an incidence of 1 000 000 cases per year. It is more frequently encountered in tropical areas but also can be diagnosed in tempered places. In France, the most exposed people are athletes in fresh water (canoeing, rafting, caving...) and agricultural workers. The peak incidence occurs in late summer. After transcutaneous or mucosal penetration, Leptospira can cause direct tissue injury by invasion, or indirect injury by toxinic and/or immunological mechanism. Also called summer flu, the clinical presentation is variable: it ranges from simple flu-like illness to septic shock with multiple organ dysfunction syndrome, with varying degrees of fever, headache or myalgia. Conjunctival suffusion is also very evocative. Biology can show thrombocytopenia, lymphopenia, cholestasis, elevated liver enzymes, renal failure, hematuria and proteinuria. Mortality occurs very rarely if organ failures (renal failure, pulmonary edema lesions ...) are undertaken by adequate therapy. The diagnosis is usually based on serology (micro-agglutination test), repeated 15 days after the first test. A first negative serology is not sufficient to rule out the diagnosis. PCR detection is also available and can facilitate the diagnosis of leptospirosis. A vaccine is available but it only protects against serogroup Icterohaemorrhagiae. It is recommended for professional expositions, but there is no consensus for leisure activities.