Abstract: Objective To understand the status of snail diffusion in Hubei Province after the flood disaster in 2020 for scientific evidence to control snail spreading in flood season. Methods By systematic sampling and environmental sampling method, we conducted survey on the snail diffusion, based on the water system in individual county, in the snail habitats together with the materials/facilities with snails lodged after the flood in 2020, and the captured snails were subjected to laboratory test. Results A total of 933 environments in 63 counties with schistosomiasis endemic and the neighboring areas were investigated in Hubei Province, which covered an environmental area of 6 965.77 hm² involved in more than 30 water systems. Snail diffusion was found in an area of 4 350.74 hm² in 20 counties with schistosomiasis endemic. In total, 1 360.39 hm² was expanded from the original environment with snails. Snail re-emerging was found in 1 856.19 hm², and newly emerging was seen in 1 134.16 hm². The 159 997 snails were captured, in which 149 928 were live snails. No infected snails were found. A total of 85 458 snails were captured from the materials/facilities in the 20 endemic counties, and the snails were most found in the trees (33 326 snails) and on the walls of infrastructure (35 581 snails), yet infected snails were free. Conclusion Although the flood disaster in 2020 led to a large area of snail spread in the schistosomiasis endemic area of Hubei Province. Nevertheless, control of snail spread in flood season should be the focus of schistosomiasis control in the future.

Key words: Schistosomiasis, Flood disaster, Diffusion of snails, Hubei Province