EVALUATION OF AN ANTIGEN-DETECTION ELISA TEST FOR THE DIAGNOSIS OF TRYPANOSOMIASIS IN NATURALLY INFECTED CATTLE

The sensitivity and the specificity of the antigen detection ELISA pro posed by Nantulya and Lindqvist (1989) for the diagnosis of African An imal Trypanosomiasis have been assessed in naturally-occurring infecti ons. 1633 cattle were sampled in trypanosomiasis endemic area and exam ined for trypanosomes by darkground/phase contrast buffy-coat method d escribed by Murray et al. (1977) and for circulating antigen by ELISA. Fifty sera from Markoye, a tsetse free area in north of Burkina Faso, and 49 sera from Germany were also tested. In trypanosomiasis infeste d area, BCT detected 144 (8.8%) positive animals while Ag-ELISA reveal ed 65.8% of positive. Out of the 144 BCT-parasite-positive, Ag-ELISA e nable to detect 75% of positive. The predominant trypanosomes identifi ed by BCT was Trypanosoma vivax followed by T. congolense while Ag-ELl SA indicated T. congolense followed by T. brucei. Ag-ELISA detected 76 .5% out of the 51 T. congolense-BCT-positive and only 17% of all T. vi vax BCT-positive. Cattle earring mixed infection involving two or thre e trypanosomes, particularly those with T. brucei and T. congolense ar e the most frequent. In tsetse free area, Ag-ELISA detected one positi ve cattle earring T. brucei and T. congolense and showed an apparent s pecificity of 98%. No serum from Germany was detected positive. This s tudy suggests the joint use of Ag-ELISA and BCT for the diagnosis of t rypanosomiasis particularly in epidemiological study in endemic area.