Falhas reprodutivas associadas com a presença de do vírus da artrite-encefalite caprina, Toxoplasma gondii e Neospora caninum em caprinos no estado de São Paulo, Brasil

Abstract

This study aimed at assessing the occurrence of antibodies against the caprine arthritis-encephalitis virus (CAEV), Toxoplasma gondii and Neospora caninum, as well as the associations between the presence of antibodies and the occurrence of reproductive failures in goats. Serum samples were collected from 923 goats of both sexes, over 3 months of age, from 17 dairy farms located in different municipalities of São Paulo State, Brazil. Infections by T. gondii, N. caninum and CAEV were evaluated by indirect methods of diagnosis based on indirect fluorescence antibody test (IFAT), Neospora agglutination test (NAT), and agar gel immunodiffusion (AGID), respectively. A survey was conducted on the farms to obtain information about reproduction dates (abortions, stillbirths and births of weak and premature kids) and zoosanitary management. Antibodies against CAEV, T. gondii and N. caninum was found in 37.81%, 23.62% and 17.23% respectively. There was no significant association between the presence of anti-CAEV antibodies and CAEV/T. gondii or CAEV/N. caninum co-infection, suggesting that CAEV does not predispose goats to infection by these agents. However, when CAEV/T. gondii (p<0.01) or CAEV/N. caninum (p<0.001) co-infection was present, the occurrence of reproductive failures was significantly higher what could indicate that CAEV-induced immunosuppression may predispose goats to develop the clinical symptoms of toxoplasmosis and neosporosis increasing the risks of the reproductive failures.

Serological response to Neospora caninum infection in goats and agreement between three diagnostic techniques to detect caprine neosporosis

“…Wide variation in the seroprevalence of caprine neosporosis have been reported in the southeastern region of the country. In the State of São Paulo, southeast Brazil, a seroprevalence of 2.7% of caprine neosporosis was reported in the IFAT assay with a cut-off point of 1:50 (Santos et al 2013) in contrast with a seroprevalence of 19.7% obtained by Modolo et al (2008) and a seroprevalence of 17.23% found by Costa et al (2012) when using the NAT with a cut-off point of 1:25. These variations in seropositivity may be due to a number of differences in each farm including herd management, herd hygiene, presence of definitive hosts in the area, climate variations, and environmental contamination (Dubey & Schares 2011).…”