| Poyang Lake is the biggest freshwater lake in China. Study on the Poyang Lake has always been valued for various disciplines, for example, one of the most important research topics is schistosomiasis and its intermediate snail host. The transmission of schistosomiasis in the region is influenced by the local natural environment, social context and other factors. The epidemic situation is complex and the prevention and control task is arduous in this area. How to more effectively take measures to control and intervene schistosomiasis transmission, especially targeted to identify the high risk regions for Schistosoma japonicum infection of human being and other mammals, and to evaluate associated social context and natural environment factors, then to take more effective measures for schistosomiasis control. All above problems are urgent and important for schistosomiasis control.In this thesis, an informational analysis of studies on the subject of "Poyang Lake" based on the scientometrics and map of scientific knowledge were studied. Some key findings, the focus studies and front fields relate to the schistosomiasis control were identified. The high risk regions for S. japonicum infection in humans and other mammals in Poyang Lake region were identified by using spatial analysis, based on epidemic situations data related to humans, cattle, wild feces and snails and digital maps. Some relative factors of the high risk regions for schistosomiasis japonica were analyzed. These factors include relationship between the change of snail indicators and the impact of water lever, the social context of the humans and cattle associated with the high risk regions.The whole study includes four parts as follows:Part Ⅰ Informational analysis of studies on the subject of "Poyang Lake" based on the scientometrics and map of scientific knowledgeStudies on the subject of "Poyang Lake" were analyzed by the scientometrics and map of scientific knowledge. Seven hot topics in the field of "Poyang Lake" were schistosoma schistosomiasis, water resources environment, flooding and so on, meanwhile the number of published papers has increased rapidly. The subject of schistosoma, schistosomiasis and snails is the most important one among these topics, which accounts for46%of the number of citations above10times. However the number of published papers has shown a tendency of fluctuation. A total of16hot topics were detected and the citation strategic diagrams was draw based on these topics in the field of schistosomiasis and snails. The comprehensive control strategy based on the interventions was the biggest concern and biggest novelty in the citation strategic diagrams. These key findings would play a very important role in the following three parts.Part II The establishment of the digital maps on the epidemic situation of schistosomiasis and the intermediate snail host in Poyang Lake regionThe digital maps on the epidemic situations of schistosomiasis and the intermediate snail host in the following counties, Nanchang, Xinjian, Duchang, Poyang, Yu’gan, and Xingzi around the Poyang Lake were established by using geographic information system and Google Earth. These digital maps are used in the next part.Part III Identifying the high risk regions for S. japonicum infection of humans and other mammals in Poyang Lake regionThe high risk regions for S.japonicum infection of humans and other mammals in Poyang Lake region were identified by using spatial analysis, based on epidemic situation data related to human beings, cattle, wild feces and snails and digital maps presented. A total of182high risk marshlands were identified among the marshlands frequented by humans and cattle, and were recognized as key regions for schistosomiasis’s control and intervention. Next step, these high risk regions were certificated by comparing the human infection rate in the area with the average infection rate of the county. We found that, the human infection rates were higher than the average rate in5counties (total6counties). However, the results were different at administrative village level.The primary study results suggest, the high risk regions for S. japonicum infection of humans and other mammals in Poyang Lake region can be identified effectively based on the infected snails and wild feces with shictosomiasis eggs by using spatial technology and analysis. These findings may provide reference for the control and intervention of schistosomiasis and snails.Part Ⅵ Study on the relative factors of the high risk regions for schistosomiasis japonicaBased on identifying the high risk regions for S. japonicum infection of humans and other mammals, specific measures could be tailored for schistosomiasis and snails control and intervention, such as to control the active transmission sites of snail habitats, to prevent humans and cattle to contact with the contaminated water. In this part, we study the change of snail indicators (area ratio with snails, density of living snails, density of infected snails and the snail infection) and the impact of water lever in Duchang Country. The results show, at the county level, the density of living snails and the density of infected snails correlate with the average water level of the first and second month and the previous dry season. The density of living snails correlate with the average water level of the current month. The area ratio with snails and the infection rate of snails correlates with the previous wet season. However, the results are different at administrative villages level. In conclusion, the change of snail indicator is different in different time, location and scale level. Therefore, the snails control measures need to be adjusted. Meanwhile, the social context of humans and cattle associated with the high risk regions was investigated. The results shown that people could contact with contaminated water through cattle grazing, hand washing, swimming and so on. Most people in the area lack awareness of the role that cattle play in the transmission of schisitosomiasis. |
PDF Full Text Request