Geographical survey of the intermediate host of Schistosoma japonicum: Toward precise management of Oncomelania hupensis

Schistosomiasis caused by Schistosoma japonicum is a public health concern in China, and Hubei is one of the most affected provinces. Although the routine surveillance since the mid 1950s has generated substantial data pertaining to the habitats of the intermediate snail host, Oncomelania hupensis, its spatiotemporal distribution is not known. A review of local chronicles on the annual records of schistosomiasis control program was conducted to retrospectively collect information about O. hupensis habitats. The habitats were mapped by a field survey in 2016. We categorized the habitats into five evolutionary types, namely, Type I, current habitat; Types II-IV, historical habitat; and Type V, suspected habitat according to habitat development. The shape of habitats was determined using geographical information systems. A visual database was established and managed on the ArcGIS platform. A total of 43 472 O. hupensis habitats, covering an area of approximately 430 000 hectares, were identified through the study. Over 60% of these habitats have been eliminated. The highest number of O. hupensis habitats was recorded in 1975; however, most of them were preserved until 1995. Our study, for the first time, sheds light on the spatiotemporal distribution of O. hupensis in the most affected province in China. The data will be valuable for policy making and for formulating strategies to eliminate schistosomiasis in Hubei Province.