Prevalence and risk factors for Leptospira spp. in dairy cattle in western Paraná, Brazil

Leptospirosis is caused by spirochete bacteria of the genus Leptospira and is considered the most widespread zoonosis worldwide. It is an important agent that causes animal production to decrease. In cattle, it affects especially the reproductive tract. The objective of this study was to determine the seroprevalence of Leptospira spp., molecularly detect the bacteria in tissues of aborted fetuses, and identify the main risk factors associated with infection in cattle in dairy farms in Western Paraná. For this purpose, 600 bovine serum samples from 60 properties and 17 bovine fetuses from nine properties were collected. Data about the properties were also collected through an epidemiological questionnaire to assess the main risk factors associated with Leptospira spp. infection. The serum samples were analyzed using microscopic agglutination test (MAT), and the fetal tissues using nested polymerase chain reaction (nested PCR). Seroprevalence of Leptospira spp. in dairy cattle in Western Paraná was 39.83% (239/600) and none of the analyzed fetuses were positive for Leptospira spp. The main risk factors identified are related to the production system, reproductive management, and the presence of dogs on the property. Leptospira spp. infection is widely spread in the cattle population in Western Paraná.