Leptospirosis in small ruminants: current epidemiological situation in Brazil

Abstract

Leptospirosis in small ruminants is a disease that can lead to economic losses due to the occurrence of abortions, stillbirths and decreased milk production. The infection can be presented in acute, chronic and inapparent forms. In the acute infection, anorexia, depression, difficulty breathing, fever, hemoglobinemia and hemoglobinuria can occur. In the chronic form, abortions and stillbirths are common. Several recent serological surveys conducted in Brazil revealed frequencies of seropositivity ranging from 3.4 to 31.3% in goats, and from 0.7 to 34.6% in sheep. Most frequent reactions were obtained with the serovars Autumnalis, Grippotyphosa, Hardjo, Icterohaemorrhagiae and Pyrogenes. The microscopic agglutination test is the most used method to diagnose the infection. The control of leptospirosis in small ruminants is based on the identification of sources of infection, rodent control, control in animal purchasing and systematic immunization with inactivated vaccines that contain regional serovars of leptospires.