Susceptibility and Infection Risk of Schistosomiasis Disease

Abstract The environment of schistosomiasis epidemic areas in China is complex with various forms of geomorphologies. The spatial distribution of schistosome (Schistosoma japonicum) and parasitic hosts is random. It is often difficult to eradicate snails(Oncomelania snails) and cercaria, and to avoid interactions with schistosomiasis-susceptible areas for livestock and humans. Rapid, efficient and timely determination of schistosomiasis-susceptible area holds significant importance. This paper first introduces the initial origin and various definitions of schistosomiasis-susceptible area. We present a new definition according to the key parameters that influence the epidemic and transmission of schistosomiasis. Secondly five study aspects of schistosomiasis-susceptible area are summarized in light of the factors that have influences on the formation of schistosomiasis- susceptible area. Problems, drawbacks and causes in different concepts and study methods of schistosomiasis-susceptible area are introduced. Perspectives of historical medical-geography study of schistosomiasis-susceptible area are reviewed. We present spatial simulation and modeling approaches that are based on remote sensing and geographic information systems(GIS) and data-driven models and knowledge-driven model. They represent an important area of new applications of remote sensing and GIS in health related problem solving. Finally, we suggest to import the concepts in hazard/risk analysis into the schistosmiasis epidemiology. This allowed us to put forward two new concepts: susceptibility level and infection risk, for which a primary calculation framework and internal relation is established. We hope to use them as the base for future studies of chistosomiasis-susceptible areas.