ABSTRACT
Objective To develop a fast, simple immunodiagnosis assay for early diagnosis of schistosomiasis. Methods The soluble cercariae antigen(SCA) labeled colloidal dye was used as the detecting antigen for schistosomiasis. A dipstick dye immunoassay(SCA-DDIA) for early diagnosis of schistosomiasis was established. The antibodies in sera of infected rabbits in early stage of infection by SCA-DDIA were detected and compared with SEA-DDIA. The sera from people with acute and chronic schistosomiasis and other parasitic diseases and from healthy people were tested by SCA-DDIA and SEA-DDIA. Results In infected rabbits during early stage of infection, the average time of antibody detected by SCA-DDIA was 22 d , at day 30 post-infection all experimental rabbits were positive with SCA-DDIA, the detected time was earlier than that with SEA-DDIA. The sensitivity of SCA-DDIA for acute, chronic schistosomiasis japonica were 100.0% and 93.3% respectively. The specificity for healthy persons was 99.0%. The cross reaction rates with paragonimiasis westermani, clonorchiasis sinensis and fasciolopsiasis buski were 26.3%, 0 and 0 respectively. The results were similar to that by SEA-DDIA. Conclusion The SCA-DDIA is more useful for early diagnosis of schistosomiasis.