PREVALENCE OF EQUINE PIROPLASMOSIS IN CENTRAL MONGOLIA

Antigen for the indirect fluorescent antibody test (IFAT) was routinel y prepared from infected erythrocytes from horses experimentally infec ted with Babesia equi and Babesia caballi. With the successful establi shment of in vitro cultures of B. equi and B. caballi, it is now possi ble to employ culture-derived antigens in this test. In this study, in vitro-propagated B. equi-and B. caballi-infected erythrocytes were us ed as antigen in the IFAT. Various modifications to an established pro tocol had to be implemented to allow repeatable results. Cultures with 3-4% parasitized erythrocytes were found to be most suitable. As cros s-reactions of control sera on heterologous antigen were observed at s erum dilutions of up to 1/40, a reciprocal titre of 80 was considered to be positive. In positive samples, specific fluorescence of Babesia parasites and/or erythrocyte membranes was observed. Fifteen sera from Babesia-free horses from Japan all tested negative in the IFAT. One h undred and ten field-horse sera from Central Mongolia were investigate d in this study. The results indicate that both B. equi and B. caballi are endemic in horses in Central Mongolia, with 88,2% and 84,5% of ho rses being seropositive to B. equi and B. caballi, respectively.