COMPARISON OF THE CIRCULATING ANODIC ANTIGEN-DETECTION ASSAY AND URINE FILTRATION TO DIAGNOSE SCHISTOSOMA-HAEMATOBIUM INFECTIONS IN MALI

The applicability of a circulating Schistosoma antigen detection assay for determining rates of infection and efficacy of chemotherapy was e valuated in Mall. Urine egg counts were compared to circulating anodic antigen enzyme-linked Immunosorbent assay (CAA-ELISA) titres in serum , before and 6 weeks after treatment with a single dose of praziquante l (40 mg/kg), in 2 villages in Dogon Country an area endemic for S. ha ematobium, the predominant schistosome infection in Mall. In Kassa, a village with a moderate prevalence of infection, the serological preva lence.(48%) was significantly higher than the parasitological prevalen ce (31%). In Bore, a village with high parasitological prevalence (76% ), no difference was observed between the results of both methods (pre valence by CAA-ELISA was 75%). Cure rates estimated by CAA-ELISA were lower than those determined parasitologically, suggesting that cure ra tes are overestimated by egg counting. The sensitivity of the CAA-ELIS A was 78%. In both villages, before treatment, a positive correlation was found between the number of eggs in urine and serum CAA titres. It is concluded that, although further simplification and improvement of the sensitivity of the assay is needed, in its present ELISA format t he antigen detection assay is useful for monitoring sentinel populatio ns. Furthermore, the serum CAA assay performed adequately in a Public health laboratory within an endemic country.