It is caused by the bacterium, Leptospira . In humans, it causes a wide range of symptoms, and some infected persons may have no symptoms at all. Individuals at risk for leptospirosis include people who work outdoors or with animals, particularly farmers, sewer workers, veterinarians, fish workers, dairy farmers or military personnel. Also, leptospirosis is a recreational hazard for campers or those who participate in outdoor sports in contaminated areas. Humans become infected through ingestion of water, food or soil contaminated with the urine of infected animals, including cattle, pigs, horses, dogs, rodents and wild animals.
Leptospirosis occurs worldwide but is most common in temperate or tropical climates.
Symptoms occur 2 days to four weeks after exposure. Diagnosis is confirmed by the detection of antibodies in blood or by identifying the organism in blood or spinal canal fluid. Leptospirosis is treated with antibiotics. Persons with symptoms suggestive of leptospirosis should contact a health care provider. The disease is not known to be spread from person to person.