THE FIELD TRIAL ON RAPID DETECTION OF SCHISTOSOMA CIRCULATING ANTIGENS WITH DOT IMMUNOGOLD FILTRATION ASSAY (DIGFA)

A total number of 2221 sera collected from different kinds of subjects,i.e.patients with various stages of schistosomiasis,nomal individuals,persons with other parasitic diseases or non-parasitic diseases,were detected with Dot Immunogold Filtration Assay (DIGFA) using anti-SVLBP IgG as capturing antibody.Positive rate of 70 sera from patients with acute schistosomiasis was 100%, and the of 307 sera with chronic schistosomiasis was 68.4% .None of 200 sera from normal indriduals showed false positive reactions.No obvious cross reaction was found in sera forom other parasitic/non-parasitic diseases except sera from patients with paragonimiasis.2 batches of sera were detected with DIGFA by single-blindness method.Results showed that sensitivities to chronic schistosomiasis were 69.4% and 68.9%, and 100% to acute schistosomiasis while specificities were 98.9%-99% .508 samples from residents in endemic areas were tested with DIGFA and Kato-Katz.Positive rate of circulating antigen was 20.9% with DIGFA while 65 samples were positive with stool examination.46 samples were positive both by DIGFA and by Kato-Katz.The coincidental rate was 70.8% .These results indicated that DIGFA showed sensitive and specific in the detection of circulating antigens.It will be useful in mass application and valuable in epidemiological survey.