RESUMO
The alkaline phosphatase immunoassay (APIA) is an antibody detection technique which permits the diagnosis of schistosomiasis using a butanolic extract preparation from adult worms. APIA has demonstrated high sensitivity and specificity in previous reports with well characterized human sera. Its potential as a diagnostic tool for epidemiological surveillance was assessed in comparison with three other diagnostic tests: stool examination, ELISA with soluble egg antigen (SEA) and the circumoval precipitin test (COPT). APIA was 100% specific in an area without Schistosoma mansoni transmission and had 89% sensitivity in an endemic area where 69% of the infected subjects excreted less than 100 eggs g of faeces. It was found to be less sensitive in children under 5 years of age who were positive by the COPT test. APIA can be applied as an initial screening test, based on its high sensitivity, specificity, absence of cross-reactivity with intestinal parasites and the fact that it is a technique suitable for use in epidemiological surveillance.
