Leptospira spp. in Free-Ranging Capybaras (Hydrochoerus hydrochaeris) from Midwestern Brazil

Background: Leptospirosis is a contagious disease that affects domestic and wild animals as well as humans. It is caused by infection with some pathogenic species of the genus Leptospira. In Brazil, studies on leptospirosis in capybaras are scarce or nonexistent in some regions, such as the Federal District. The objective of this study was to analyze the presence of DNA of the agent and/or anti-Leptospira spp. antibodies in capybaras. Materials and Methods: Blood samples were collected from 56 free-living capybaras captured in two different sites in the study region. The samples were submitted to hematology and clinical chemistry tests. To identify Leptospira positive samples, a conventional PCR (cPCR) and analysis of anti-Leptospira spp. antibodies by microscopic agglutination test (MAT) were used. Results: No animal showed cPCR amplification of the Lip32 gene, but 41.1% (23/56) of the animals had anti-Leptospira spp. antibodies on MAT. The serovars present were icterohaemorrhagiae (82.61%), copenhageni (65.22%), grippotyphosa (4.35%), and hardjo (4.35%). In the laboratorial tests, differences (p < 0.05) were observed in the biochemical assays of alkaline phosphatase, creatinine, albumin, and globulin. Although these values differed significantly between groups, they all remained within reference range (excluding albumin), and thus there is not enough to infer that this alteration could be caused by Leptospira infection. Conclusions: cPCR using whole blood samples to evaluate Leptospira spp. infection of free-living capybaras was not an efficient tool. The presence of Leptospira seroreactive capybaras shows that the bacteria are circulating in the urban environment of the Federal District.