Objective: To evaluate the efficacy of five diagnostic test kits for the detection of antibodies to Schistosoma japonicum in endemic areas of Poyang Lake.
Methods: Residents over 5 years old in three schistosomiasis-endemic administrative villages in the lake region were simultaneously examined by modified Kato-Katz thick smears and nylon bag sedimentation/hatching method. At the same time, five sero-diagnostic test kits for detection of IgG antibody against soluble egg antigen of S. japonicum were carried out.
Results: The distribution of seropositive rates of S. japonicum IgG antibodies determined by sero-diagnostic tests showed similar trends with that of egg positive rates in different age groups, but the seropositive rate (33.1%-57.1%) was significantly higher than that of egg positive rate (5.0%-8.2%), both reached a peak in 40-49-year-old group. The antibody positive rates determined by each test increased with the infection intensity. The sensitivity of the evaluated test kits ranged from 81.2%-94.5%. 26.9% to 46.1% among those egg negatives were antibody positive by the kits. Furthermore, 5.5%-18.8% of the egg positives were antibody negative by the kits.
Conclusion: The five sero-diagnostic kits can be used for epidemiological survey in schistosomiasis endemic areas at community level. Among them, enzyme-linked immunosorbent assay shows higher sensitivity.