ABSTRACT
Objective To understand the potential impact of south-north water transfer project on transmission and distribution of Schistosomiasis japonica, and to put forward the countermea-sures of prevention of the disease transferring into other places. Methods The information on the progress of south-north water transfer project and factors related to the distribution of Schistosoma juponicum were collected, and the suggestions on improving the countermeasures were obtained through the group discussions and field visits. Results The potential impact of the project on the disease transferring is existed, mainly the disease transferring will be through the Lixia River basin in Jiangsu Province, and Chaohu areas of Anhui Province in the east route, and Sihu areas of Hubei Province in the middle route. The snail transferring northward will be affected both by the project and global warming, as a result, the endemic areas of Schistosomiasis will probably transfer into the Hongzehu and Chaohu areas in the future. Conclusion In the east route of the project, if the project is not combined with Schistosomiasis control, the endemic areas of Schistosomiasis will extend into other regions, the loss in the society and economy will be very large.
ABSTRACT
Objective To evaluate the effectiveness of the current measure of Oncomelania hupensis control in Jiangsu Province. Methods The snail control was carried out with molluscicides in the high transmission areas every year. Some snail habitat areas were modified. The snail areas within three years were re-treated with molluscicides in the maintenance phase. The snail survey was carried out every spring, and the data were analysed with SAS software. Results From 1995 to 2001, 14519.17 hm 2 of snail habitats were molluscicided, 2768.57 hm 2 were modified, and 8803.64 hm 2 were re-treated with molluscicides in the maintenance phase. The coverage rates of snail control areas dropped by 19.14% every year. The snail areas increased by 6.25% every year from 1995 to 2002. In which, the areas of infected snails increased by 18.52% every year. The correlation analysis showed that the areas of infected snails increased with the increasing of the total snail areas. At the same time, the areas of infected snails increased with the fall of the coverage rates of snail control areas. The analysis of the snail distribution showed that the main problem was poor snail control. Conclusion In recent years, the rise of area of snail habitats is serious in Jiangsu Province. The present measures of the snail control have not effectively stopped the spreading and increasing of snails. The research on the new molluscicides, the new methods of snail control and the better policies are very important.