[Oncomelania hupensis status monitoring in Changzhou City, Jiangsu Province from 2013 to 2016].

Objective To analyze the Oncomelania hupensis snail distribution and the changes of snail situation in Changzhou City from 2013 to 2016, so as to provide the evidence for formulating the schistosomiasis prevention and control interventions. Methods The data of snail monitoring in Changzhou City from 2013 to 2016 were collected and statistically analyzed. Results The total area with snails was 40.17 hm2 and the newly discovered area was 30.63 hm2 in Changzhou City from 2013 to 2016. In the four years, 3 454 snails were dissected, and no schistosome infected snails were found. There were totally 51 spots with snails, and the areas with snails of different types of marshland, inland and mountain were 12.13 (30.19%), 25.54 hm2 (63.57%) and 2.51 hm2 (6.24%), respectively. In the newly discovered snail environment, the areas of types of marshland and inland were 8.00 hm2 (26.12%) and 22.63 hm2 (73.88%), respectively. The main causes for snail existence were external input and adjacent diffusion. In the past four years, the total snail control area with molluscicides was 71.74 hm2, the consolidated snail control area with molluscicides was 155.15 hm2, and the total environmental modification areas in the current snail spots and historic snail spots were 15.90 hm2 and 11.30 hm2 respectively. Conclusion The diffusion of snails in inland rivers is the key of the newly discovered snail areas in Changzhou City in recent years, and the snail monitoring and control measures should be strengthened in the future.