Comparison of Neospora caninum distribution, parasite loads and lesions between epidemic and endemic bovine abortion cases.

摘要

It has been suggested that the abortion herd pattern could influence bovine fetal neosporosis. Here, a comparison of (i) Neospora caninum DNA-detectability by PCR, (ii) N. caninum-associated lesions and (iii) parasite loads in target organs was made between epidemic and endemic abortion cases. We observed that N. caninum DNA was predominantly detected in more than one organ in the fetuses from herds with epizootic rather than endemic abortion cases (P&0.05, Fisher F-test). The highest parasite burdens were found in the heart in fetuses from outbreaks of epidemic abortion and in the brain in endemic cases (P&0.05, Kruskal-Wallis H-test). Moreover, fetuses from epidemic outbreaks had significantly higher parasite burdens in heart (P&0.05, Mann-Whitney U-test) than endemic abortion cases. Epidemic abortion cases showed higher lesion frequencies in liver (P&0.05, Fisher F-test). This report confirms that the abortion herd pattern is an important factor that influences pathogenesis in natural N. caninum infections..