leptospirosis /lep′tōspīrō″sis/ [Gk, leptos + speira + osis, condition] , an acute infectious disease caused by several serotypes of the spirochete Leptospira interrogans, considered the most common zoonosis globally. It is transmitted in the urine of infected cattle, horses, pigs, dogs, rodents, or wild animals. Human infections arise directly from bacterial contact with mucous membranes or abraded skin with an infected animal’s urine or tissues or indirectly from contact with contaminated water, food, or soil. Occupational contamination accounts for 30% to 50% of the cases. It is increasingly recognized as a disease of recreation. Clinical symptoms may include hepatitis, jaundice, hemorrhage into the skin, fever, chills, renal failure, meningitis with mental status changes, and muscular pain. The spirochete can be isolated from the urine or blood during the acute stage of the disease, and antibodies can be found in the patient’s blood during convalescence. Treatment with antibiotics, usually penicillin or doxycycline, may be effective if it is administered during the first few days of the disease. Fluid and electrolyte replacement is essential if jaundice or other signs of severe illness are present. The disease is usually short-lived and mild, but severe infections can damage the kidneys and the liver. Blood pressure and vital signs should be monitored, and the patient’s urine should be disposed of carefully to prevent spread of the organism. The most serious form of the disease, Weil’s disease, makes up 5% to 10% of leptospirosis cases. Also called autumn fever, mud fever. See also nanukayami.
