ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA) FOR THE IMMUNODIAGNOSIS OF SCHISTOSOMIASIS

The enzyme-linked immunosorbent assay (ELISA) done with soluble egg antigens (SEA) of Schistosoma mansoni was utilized for the detection of infections with schistosomes. The method readily detected experimental infections in NIH outbred, New Zealand black, and New Zealand white mice by 6-10 weeks post-exposure to S. mansoni cercariae. In addition, the test was negative when the sera from 11 Puerto Rican normal controls were examined and was positive in 8 of 10 serum samples from humans with schistosomiasis mansoni. However, extensive cross-reactivity was seen when using serum from humans with fascioliasis, trichinosis, cysticercosis, and echinococcosis. Thus the ELISA test done with SEA as antigen lacks immunologic specificity. For the method to be an effective seroepidemiological tool in areas where these parasites are endemic further purification of the antigen and more extensive understanding of its components are needed.