SERODIAGNOSIS OF BABESIA-EQUI INFECTION - A COMPARISON OF DOT-ELISA, COMPLEMENT-FIXATION TEST AND CAPILLARY-TUBE AGGLUTINATION-TEST

The present study aimed to develop Dot-ELISA, complement fixation test (CFT) and capillary tube agglutination test (CAT) for serodiagnosis o f Babesia equi infection and to compare their sensitivity with each ot her. For this study, sequential serum samples were collected from four donkeys experimentally infected with B. equi up to 90 days post infec tion(P.I.). B. equi antigen was prepared from the blood of a donkey sh owing more than 80% parasitaemia. Dot-ELISA, CF and CA tests were stan dardized as per the standard method. While performing CFT, it was obse rved that CFT standardized for the donkey system could not be applied to the horse system, and different units of the same antigen and compl ement were required for each. Dot-ELISA detected antibodies from 3-6 d ays P.I. onwards, whereas CF and CA tests could detect antibodies from the 6th day P.I. indicating that Dot-ELISA is the more sensitive. The efficacy of these three tests was also determined by testing 211 fiel d serum samples of apparently healthy horses. By Dot-ELISA 49.76%, by CAT 42.18% and by CFT 27.86% of the serum samples were found positive. As the results of Dot-ELISA and CAT are comparable, it is proposed th at CAT may be used as a screening test. (C) 1997 Elsevier Science B.V.