Abstract: Objective To evaluate the risk of schistosomiasis transmission in river channels connecting the Yangtze River in Nanjing City,so as to provide evidence for strengthening the control measures and reducing the risk of schistosomiasis transmission. Methods Snail monitoring,human and animal activity investigation,and infection source monitoring were carried out to grasp the risk factors of schistosomiasis transmission in river channels connecting the Yangtze River in Nanjing City,including Chu River,Bianmin River,and Shuiyang River. The risk level was evaluated by the three-dimensional risk matrix method. Results Snail monitoring was carried out in 12 environments in river channels connecting the Yangtze River,and the average density of live snails was 0.20/frame,and no infectious snails were found. The inspection along the river found that there were 10 environments with crowd activities and 4 environments with cattle and sheep grazing. A total of 7 273 residents along the river were investigated for schistosomiasis,with a positive rate of 2.17%. A total of 57 samples of wild feces were detected by miracidium hatching method,and no positive results were detected. A total of 31 wild mice were captured with a density of 2.58%. The results of three-dimensional risk matrix evaluation showed that the Bianmin River in Qixia District and the Chu River in Liuhe District were medium risk,and the Shuiyang River in Gaochun District was high risk. Conclusions The risk factors of schistosomiasis transmission in river channels connecting the Yangtze River in Nanjing City still exist. The risk levels of the Bianmin River and the Chu River are medium,and the Shuiyang River is high. Competent authorities are advised to strengthen the comprehensive environmental management,and strengthen regional joint prevention and control. Meanwhile,it is necessary to improve the schistosomiasis surveillance system to detect and eliminate potential transmission risks in time.

Key words: Schistosomiasis, River channels connecting the Yangtze River, Risk assessment