Schistosoma japonicum: use of a radioimmunoassay for anti egg antibodies in human sera.

A solid-phase radioimmunoassay (RIA) was developed for schistosomiasis japonica using extracted egg antigens and compared with circumoval precipitin test (COPT) results on 20 sera from known S. japonicum-infected individuals and on 10 control sera. The quantitative RIA very clearly differentiated between infected and uninfected individuals with highest titers being obtained in teenagers. However, in the series employed, information relevant to immunodiagnosis of S. japonicum infection was contained in the non-quantitative but simple COPT and little was apparently added to the quantitative but expensive RIA.