Distribution of Oncomelania hupensis snails in Hunan Province, 2016
XIA Meng, ZHOU Jie, ZHAO Zheng-yuan, HU Ben-jiao, TANG Ling, LI Guang-ping, LUO Zhi-hong, REN Guang-hui
Hunan Institute of Schistosomiasis Control, WHO Collaborating Center for Research and Control on Schistosomiasis in Lake Region, Yueyang, Hunan 414000, China
Abstract:Objective To further investigate the distribution regularity of Oncomelania hupensis snails in Hunan Province so as to provide a basis for implementing the accurate schistosomiasis control strategy in the province. Methods In accordance with the requirements for the national census of Oncomelania hupensis snail by National Health and Family Planning Commission and the National Scheme on Oncomelania hupensis Snail Survey formulated by National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, a provincial-wide survey on existing, historical and suspicious habitats for Oncomelania hupensis snails in Hunan Province was conducted via system sampling combined with environment-based sampling in the spring of 2016. Based on the database in this survey, the corresponding snail indicators at the provincial level, such as the existing distribution areas, epidemiological types, environmental types and vegetation kinds were reviewed. Results Totally, 3.9207 million frames were sampled for snails checking from an area of 3.249 billion m2 in the whole province, with a collection of 319.5 thousand snails and a density of 0.081 living snail/frame. There were a total area of 1.663 billion m2 and 1,707 snail breeding places detected, of which 912 places were attributed to within the embankment areas, with a total area of 17.2548 million m2. Among the 41 counties endemic for schistosomiasis on record, the existing habitats of Oncomelania hupensis snails were found in 31 counties, which were distributed in 743 administrative villages of 170 townships. Marshland dominated over the epidemiological types of the existing endemic areas, accounting for 97.5% of the total areas with the snails. 54.5% of snail habitats were located in the low-lying zones of marshland areas. And Weeds accounted for 70.5% of the vegetation types. A snail census in the provincial-wide covering 41 counties endemic for schistosomiasis on record was conducted in 2016, and the snail data compilation, collection of geographically environmental information in snail habitats and map drawing based on GPS from this investigation were also completed. Conclusions The distribution profile of Oncomelania hupensis snails in Hunan Province is comprehensively surveyed through this snail census,and its results can provide a basis for surveillance, prevention and control of the epidemic situation of schistosomiasis.