Complete diagnosis of leptospirosis in tropical reproductive cattle

Abstract

Leptospirosis is a worlwide zoonosis of great impact in both animal and public health. Bovine leptospirosis is commonly manifested by reproductive disorders, such as abortion, stillbirth and infertility; causing depletion of the economic balance of livestock farms, along with representing a health risk problem for farm workers. In view of these consequences, we aimed to evaluate the sanitary status of tropical cattle and their role as reproductive disseminators of leptospirosis. We analyzed blood and semen samples from 11 brazilian herds by three diagnostic methods -Culture, Microscopic Agglutination Test and Polymerase Chain Reaction. All animals were negative for bacteriological culture in Fletchers semisolid medium; 66% (264/400) animals were seropositive to at least one of 19 serovars (17 serogroups) of Leptospira spp. by MAT, given that 42.4% and 5.3% of animals presented titers against brazilians isolates Guaricura and Nupezo, respectively; furthermore, five animals were positive by PCR in blood and/or culture samples and three semen samples were positive by PCR (one of them also seropositive). These results highlight the coexistence of both disease's stages (acute and chronic) in the same environment, thus alert for venereal dissemination of leptospirosis, aggravating their sanitary condition and fomenting economic losses. We, authors, recommend the adoption of prophylactic measures, such as systemic vaccination, treatment of animals and improvement of hygienic-sanitary conditions.