Abstract:

Objective: To research the effect of specific immunity against Schistosoma japonicum on infection rate of schistosomiasis in human. Methods: 91（A group）with positive stool examination of S. japonicum and 223 negative individual（B group）have been selected as research object. After treatment with praziquantel for 10 days, the two groups simultaneously were exposed in rich planting period. Moreover, after planting period for 30 days, fecal examination was also used to observe infection rate whether there were different, in order to infer specific immunity against schistosome infection influence. Results: The infection rate of group A （reinfection） was 38.46%（35/91）, in which children aged 6-14 with the infection rate（re-infection）of 10.53%（2/19）; the infection rate of 15-60 year olds（re-infection rate）was 45.83%（33/72）. The infection rate of group B（re-infection）was 29.60%（66/223）,
in which children aged 6-14 with the infection rate （re-infection）of 20.27% （15/74）; the infection rate of 15-60 year olds （reinfection rate）was 34.23% （51/149）. Conclusion: The specific immunity is relatively low and week resulted from S. japonicum infection, and it had no significant effect in reducing infection rate.

Key words: Schistosoma japonicum, specific immunity, infection rate