Leptospirosis, the disease of humans and animals caused by the spirochete (a type of bacteria) Leptospira, has become increasingly evident in Michigan within the last few years. These bacteria are found worldwide, with infections being most prominent in temperate or tropical areas. The bacteria are shed in urine of infected animals (and people), and can survive in surface water for extended periods of time. Most people and animals become infected by swallowing contaminated food or water, or through skin contact (especially mucosal surfaces).

Leptospirosis usually occurs in people with occupations that bring them into contact with contaminated waters/animals or in people who frequently do outdoor activities. Following an incubation period of 2-4 weeks the illness begins abruptly with fever and other clinical signs. There are two phases of the disease. During Phase One the individual will have chills, headache, fever, muscle aching, vomiting and diarrhea. There is then a period of apparent recovery followed by Phase Two involving kidney or liver failure, and/or meningitis (inflammation of the lining of the brain and spinal cord). Illness lasts a few days to 3 weeks or longer. Without antibiotic treatment, recovery may take several months.

This disease affects cattle, horses, dogs, rodents, and wild animals. The infection may be inapparent or may have mild to severe clinical signs. The incubation period in animals is 4-12 days followed by fever, depression, anorexia and generalized pain. These mild signs progress into blood coagulation abnormalities, dehydration, vomiting, oral ulcerations, abortions, kidney or liver damage, meningitis, and possibly death. Treatment for the disease involves fluid therapy and antibiotics.

There are vaccines protecting dogs against Leptospira, although vaccination is not 100% protective. People should avoid waters that may be contaminated with animal urine. People exposed to contaminated water/soil should also wear protective clothing or footwear.