Seroprevalence of Neospora caninum and risk factors associated with infection in water buffaloes (Bubalus bubalis) from Maranhão State, Brazil.

The aim of this work was to determine the seroprevalence of Neospora caninum in buffaloes (Bubalus bubalis) from Maranhão State, Brazil, and identify risk factors associated with infection. In total, 338 buffaloes of different ages and both sexes from four farms were randomly selected. Information about the study region, animals and management was collected using an epidemiological questionnaire. Sera were subjected to an indirect fluorescent antibody test (IFAT) to detect anti-N caninum antibodies, while N. caninum DNA was detected using the polymerase chain reaction (PCR) assays. The overall seroprevalence of N. caninum in buffaloes was 27.5% (93/338), while DNA was detected in 3.0% (3/101) samples. The proportion of positive animals detected by IFAT and PCR simultaneously was 2.6% (2/77). The risk factors for N. caninum infection were contact with fomites (p = 0.022), management conditions (p = 0.005), calving interval of 20 months (p = 0.010) and deworming management (application 3 times a year in adults and calves, p = 0.020; change of anthelmintic group, p = 0.040). By multivariate analysis, management conditions was a risk factor for N. caninum infection with odds ratio of 2.2 (95% CI 1.0-4.6). This is the first report of the prevalence and risk factors for neosporosis in B. bubalis of Maranhão State, Brazil. Thus, N. caninum is widely distributed in buffalo herds in Maranhão, with management conditions being a risk factor for infection. Further studies should be conducted to elucidate the importance of buffaloes in the epidemiology of neosporosis in Maranhão State.