[Surveillance of endemic situation of schistosomiasis in Gaoyou sections in east route of South-to-North Water Diversion Project before water transfer].

Objective: To understand the endemic situation of schistosomiasis and the distribution of Oncomelania hupensis snails in Gaoyou sections in the east route of the South-to-North Water Diversion Project before water transfer.

Methods: The Grand Canal, the Sanyang River and the range of 3 kilometers of both sides of the rivers were chosen as the surveillance area in the Gaoyou sections in the east route of the South-to-North Water Diversion Project, and the Gaoyou Lake area adjacent to the east route was also chosen as the surveillance area. The human and livestock schistosomiasis and Oncomelania hupensis snails were monitored by the conventional method. Three underwater snail surveillance sites were set up in the Grand Canal and the Sanyang River respectively, and the net salvage method and the method of attracting snails with rice straw curtains were used to survey the snails underwater in the surveillance sites.

Results: The schistosome infected snails, the human and livestock schistosomiasis were not found in the Gaoyou sections in the east route of the South-to-North Water Diversion Project from 2006 to 2012. The snail areas were on the decline in the Grand Canal. The snail was not found in the Sanyang River. A total of 270 kg floatage was refloated and 720 pieces of rice straw curtains were placed in the surveillance sites, and there were no snails in the floatage and the rice straw curtains.

Conclusion: There is no evidence showing that the snails spread to northward in the Gaoyou sections in the east route of the South-to-North Water Diversion Project.