[A preliminary study on diagnosis of schistosomiasis japonica by indirect immunoperoxidase assay using daughter sporocyst-containing Oncomelania tissue sections].

Schistosoma japonicum daughter sporocysts in Oncomelania tissue sections were, for the first time, used as antigen in the diagnosis of schistosomiasis japonica by indirect immunoperoxidase assay (IIPA-DS). The most strong peroxidase reaction was localized on the tegument of the daughter sporocysts and cercariae, and at some parts of cercarial parenchyma, when IIPA-DS was carried out. Of 112 sera from proven cases of schistosomiasis japonica, 106 (94.6%) were positive, the range of titre dilution was from 1:1 to 1:160, the geometric mean of titres was 1:20. IIPA-DS highly coincided with IHA, COP and ELISA in both sensitivity and strength of reaction. Sera from 101 blood donors and 24 normal rabbits were all negative. No cross reaction with sera from 24 patients with paragonimiasis was observed.