What Is Leptospirosis?

Leptospira species are bacteria found in many animals but are most commonly associated with livestock and dogs. Transmission from laboratory rodents to people has been reported. It causes an acute febrile illness with fever, headache, nausea, and vomiting. Leptospirosis in animals is often subclinical- an infected animal may appear healthy even as it sheds the bacteria in its urine.

Routes of Infection

Humans become infected with Leptospires after exposure to fresh urine. The bacterial infect humans by invasion across mucosal surfaces or non-intact skin. Infection may occur via direct contact with urine or through contact with contaminated water and soil. In favorable conditions, leptospires can survive in fresh water for as many as 16 days and in soil for as many as 24 days.


In 10 percent of cases, leptospirosis presentation is dramatic and reaches mortality rates of 10 percent.


Leptospira infection can be prevented by taking the appropriate precautions when handling rodents of unknown lymphochoriomeningitis virus (LCMV) status. Keeping wild rodents out of the animal facility is an important step to prevention of leptospirosis in the laboratory rodent population.