“…Under certain conditions, some serologic tests can better estimate the real prevalence of this parasitosis than the classical stool exams (Noya et al 1999). Techniques for detection of circulating antigens have not attained yet an acceptable degree of sensitivity for the diagnosis of individuals with low parasitic loads (El-Morshedy et al 1996), but methodologies that detect specific antibodies have shown sensitivity indices close to 100% (Lima et al 1996). The indirect immunofluorescence tests on worm paraffin (IgM-IFT) or frozen sections (IgG-IFT) have presented satisfactory degrees of sensitivity and specificity for diagnosis of schistosomiasis (Kanamura et al 1979, Deelder & Kornelis 1981, Silva et al 1992.…”