Seroprevalence and risk factors associated with Neospora caninum in dairy farms from the Province of Salta, Argentina

The objective of this work was to determine the seroprevalence of Neospora caninum in cattle in Valle de Lerma, province of Salta, Argentina, and the risk factors associated with the disease. Serum samples were taken from 40 cows in each dairy herd, which were analyzedby indirect ELISA to detect antibodies against N. caninum. Chronic and acute infections were discriminated by measuring the avidity of these antibodies. All the herds exhibited at least one seropositive animal, the mean being 35.3 +/- 14.9% of positive animals. Specific antibodies were also detected in dogs present in 9 of the herds, which showed a seropositivity value of 71.7% +/- 19.9%. Among the seropositive animals, 56.3% showed acute infections. A negative association was found between seroprevalence and the avidity index of specific antibodies, indicating thatthe presence of animals with acute infections is associated with higher seroprevalence. Fields with grazing showed more recent infections. These results show for the first time the importance of this parasite in this particular region and the need to promote the development of control programs considering the different risk factors that affect the epidemiological situation of the disease. (C) 2020 Asociacion Argentina de Microbiologia. Published by Elsevier Espana, S.L.U.