Abstract: 　AIM: To assess the preventive effect of oral artesunate against S.japonicum infection. METHODS:Residents in two pilots in the schistosomiasis endemic regions, 562 cases in Yanghe pilot,Wangjiang County and 218 cases in Shashan pilot,Guichi City,Anhui Province, were selected for this study. The residents were divided into two groups.Group Ⅰ received artesunate 6 mg/kg once every 2 weeks for 4 times 2 wk after contacting with infested water from July to September in 1997.Group Ⅱ received the same dosage of placebo at the corresponding times.Four weeks after the last administration,stool examination using hatching method and Katos method was conducted to evaluate the effect.RESULTS: In Yanghe pilot,2 cases were hatching positive in the artesunate-treated group with an infection rate of 0.7%(2/273), while 11 cases were stool positive in placebo group with an infection rate of 3.8%( 11/289)and a mean EPG of 26.40±1.49.In Shashan pilot,all cases in artesunate-treated group were stool negative, while 7 cases were stool positive in the placebo group with an infection rate of 6.3%(7/111),and a mean EPG of 14.23±2.14.The protection rate of artesunate was 80.9% and 100%,respectively,in the two pilots. CONCLUSION:Artesunate can protect the residents from S.japonicum infection effectively.

Key words: Artesunate, prevention, schistosomiasis japonica