a contagious disease of animals,including man,due to infection with various leptospiral organisms,which are grouped into immunologically distinct serovars.Infections may be asymptomatic or may result in a variety of disease conditions including fever,icterus,hemoglobinuria,abortion,and death.Following acute infection,leptospires frequently localize in the kidneys and are shed in the urine,sometimes in large numbers for months or years.Leptospirosis is essentially a water-borne disease; the organisms survive in surface waters for extended periods