Diagnosis and seroepidemiology of Neospora caninum-associated bovine abortion.

A round table was conducted at the VIIIth International Coccidiosis Conference on Neospora diagnosis with particular emphasis on strategies to diagnose bovine abortion. The strength and weakness of different assays for Neospora caninum infection and whether these methods have resulted in the overdiagnosis of neosporosis was discussed. It was evident that each diagnostic method, namely histology, immunohistochemistry, molecular detection and serological assays were, under certain circumstances, valuable in assessing the role N. caninum in abortion. Histological, immunohistochemical and molecular detection assays are of outstanding importance for the examination of tissues of aborted foetuses. While histology and immunohistochemistry allow direct assessment of pathomorphological changes caused by infection, molecular detection assays such as PCR are superior because of higher sensitivity and specificity in identifying N. caninum in foetal tissues. Serological tests, such as ELISA, are useful in determining whether an animal has been infected with N. caninum. Seroepidemiological approaches allow one to assess an abortion problem at a herd level and when used in conjunction with certain statistical methods are able to confirm a suspected N. caninum-associated abortion.