Serological Survey of Neospora caninum in Imported Cattle and Evaluation of ELISA for Detection of Antibodies

A serological survey of Neospora caninum in imported cattle during 1996-1999 was conducted. Stored sera obtained from 1, 184 cattle originated from 30 herds were tested by IFA test, and 15 (50%) of 30 herds and 33 (2.8%) of 1, 184 cattle were sero-positive. The identified sero-prevalence in this study was lower than the one (5.7%) reported previously among domestic cattle. There were no significant differences in the sero-prevalence among the factors such as countries, year, breed and sex. These results indicated that N. caninum were widely distributed without specific geographical or other factor related clusterings. Follow-up survey revealed that 8 cattle (28%) of 28 sero-positive cattle had abortions and stillbirth, and 2 of them were diagnosed as N. caninum infections. The diagnostic results of IFA were highly in accordance with the ones by protein AG-ELISA, therefore, protein AG-ELISA may be a useful screening test for the cases of large sample size.