Abstract: AIM:To explore if there are some antibody responses to be correlated strongly with susceptibility to reinfection of S.japonicum.METHODS:A group of1 96 individuals aged3 - 25 years old in a schistosomiasis endemic area in Nanshan Island of Poyang Lake,who were treated and followed up for identification of reinfection over a 10 - month period during which intense transmission continued in the study area.Serology for testing isotype- restricted antibody responses quantitatively to SEA and WA was performed according to predetermined design in the cohort. RESULTS: After allowing for age and exposure in a logistic regression analysis, IgG4 antibodies were significantly related to susceptibility to reinfection. The individuals with high levels of SEA-specific IgG4 and/or WA-specific IgG4 being 2.83 and 2.40 times were more likely to become reinfected after treatment. CONCLUSION: These findingsmay form a basis for construction of prognostic tests predicting the probability of reinfection and targeting treatment leading to a reduction in drug costs of chemotherapy

Key words: Schistosomiasis japonica, reinfection, isotype- restricted antibodies