Objective To evaluate the comprehensive benefit about the installation obstructed snails in large irrigation canals for preventing snails spreading in lake-swamp areas of schistosomiasis.Methods The installation obstructed snails was set up in upper reaches of main canal Shilong, Tianmen City Data of snails and schistosomiasis prevalance were collected and analysed. The comprehesive benefit was analysed with the cost-benefit methods of economic hygienics. Results After the installation obstructed snails was set up the snails areas and human infection rate decreased markedly. New patients with acute and advanced schistosomiasis were not found in the irrigation areas. The ratio of comprehesive cost-benefit was 1∶9.84,the ratio of net benefit was 8.84∶1. Conclusion Setting up the installation obstracted snails to cut off the way of snails spreading was the effective measure of control schistosomiasis in lake-swamp areas.

Objective To evaluate the cost-effectiveness and -benefit of the World Bank Loan Project on Schistosomiasis Control in Qianjiang City. Methods According to the national scheme the cost-effectiveness and cost-benefit of the project were analysed. Results After the project was carried out for 9 years, poputation schistosome infections rate decreased by 56.48%; cattle infections rate decreased by 48.08%; snail areas reduced 1224 hm 2(42.76%). Infected snail areas reduced 273 hm 2(17.13%). Snail infections rate decreased by 97.04%. The investment for infections rate decreased by 1% in 100 people was 1384.47 yuan. The investment for infections rate decreased by 1% in 100 head of cattle was 3386.96 yuan. The investment to reduce 1 hm 2 snail ares was 8935.63 yuan. Conclusion For one yuan investment, the benefit was 7.96 yuan and the total of the net benefit was 106784700 yuan in 9 years.