Neospora caninum: Seroprevalence and DNA detection in blood of sheep from Aguascalientes, Mexico

The purpose of this study was to determine the seroprevalence of anti-Neospora caninum antibodies, the prevalence of the parasite's DNA in blood and to estimate the association between seroprevalence and potential risk factors in sheep herds in Aguascalientes, Mexico. A total of 324 blood samples were taken from 13 farms and tested using ELISA in order to detect N. caninum antibodies and nested PCR was used to determine the prevalence of the parasite's DNA in blood. The association between seroprevalence and some potential risk factors was estimated. The general seroprevalence reached 5.5% (18/324; 95% C.I. 3-8), ranging between 4 and 15% with the presence of seropositive animals in 61.5% of the farms; seroprevalence in ewes was 5.2% (15/286; 95% C.I. 3-8) while in rams it reached 7.9% (3/38; 95% C.I. 2-22). The prevalence of the parasite's DNA in blood was 25% (81/324; 95% C.I. 20-30), with a range from 7.7 to 50%, with 84.6% of the flock with at least one positive animal. Were identified as positive to both tests the 3% of the animals probed (10/324; 95% C.I. 1-5) of which nine were ewes and only one ram. The agreement between tests was k = 0.12. No association statistically significant was found between seroprevalence and the risk factors considered in this study.