Their urine can then contaminate water, moist soil, or vegetation with the Leptospira bacterium. Humans can acquire the infection if this contaminated material contacts abraded skin, mucous membranes, or is ingested. Although all persons are susceptible, this uncommon infection occurs mainly in persons whose occupation brings them into contact with animals or with material contaminated with animal urine. Farmers, veterinarians, slaughterhouse workers, sewer workers, and miners are at greater risk of exposure. Although rare, exposures can also occur during recreational activities such as camping or swimming, when there may be contact with or ingestion of contaminated water.
Leptospirosis occurs most often in the summer and in warm climates.
Symptoms usually appear 7 to 13 days after exposure, with a range of 2 to 26 days. The diagnosis can be made by culturing the Leptospira bacterium from body fluids, or by finding elevated levels of antibodies to the bacterium in the patient's blood. Because of non-specific symptoms during early infection, leptospirosis is frequently not considered as a diagnosis until later in illness. Several antibiotics such as penicillin, doxycycline, tetracycline, clindamycin, and erythromycin can be used to treat leptospirosis. Some severely ill patients may require kidney dialysis.