DO INTESTINAL PARASITES INTERFERE WITH THE SEROEPIDEMIOLOGIC SURVEILLANCE OF SCHISTOSOMA-MANSONI INFECTION

In view of the known cross-reactivity of sera from patients with intes tinal parasites to some Schistosoma mansoni antigens, field work was c onducted in an area of Venezuela non-endemic for schistosomiasis using the routine immunoenzymatic assay (ELISA) with soluble egg antigen (S EA). False positive reactions represented 15.3% of the total populatio n as determined by SEA-ELISA. SEA-immunoblotting of the false positive sera indicated that protein fractions of 91 and 80 kDa appear to be r esponsible for cross-reactivity. Sera from hookworm infected individua ls produced a higher frequency and intensity of cross-reaction than ot her sera. SEA-fractions of 105, 54, 46, 42, 32, 25 and 15 kDa were the most specific.