Study On Endemic Trend Of Schistosomiasis In Hubei With Spatial Statistic Technique

【Objectives】Our study attempted to built up a basic data base and mapping endemic area of Schistosomiasis in Hubei province with Geography Information System (GIS). And so to visualize the spatio-temporal distribution of schistosomiasis at regional scale, the spreading trend of the disease has been revealed easily. The influence factors and transmission mechanism have been discussed based on result of snail and related climate factors. Spatial analysis techniques to explore the natural focal disease in the application, but also for further prevention and control of schistosomiasis has provided new ideas and methods.【Methods】The incidence data of schistosomiasis during 2004-2008 in 47 cities and counties of Hubei province was collected. At the same time, basic geographic information data at 1:5,000,000 and their climate data were also obtained including the annual average temperature, the annual higher temperature, annual lowest temperature, annual average relative humidity, sunshine hours and annual precipitation. With the geographic information soft MapInfo 8.0 and ArcGIS 9.2, using overlay analysis and spatial statistical analysis method of combining temporal and spatial distribution of schistosomiasis in Hubei Province and trends in mapping, the spatial distribution of the statistical analysis and the use of SPSS statistical software-related environmental factors of schistosomiasis regression analysis to identify possible environmental risk factors.【Results】It is indicated that there is obvious high incidence area and low incidence area in Hubei province by using a special schistosomiasis case interpolating charts and map overlay analysis. The results from incidence data of schistosomiasis from 2004 to 2008 and analysis from the spatial statistics of snail show that the Moran's I index is from 0.25 to 0.32 (p<0.01), indicating that there is a positive spatial correlation between the infection rate of schistosomiasis and snail square. The distribution of schistosomiasis is of clustering. The Getis's G index was found to be between 1.34 to 1.75 (p<0.01), indicating there is a clustering not only of snail square , but also of high incidence of schistosomiasis. As the time changes, there is a trend that epidemic transforms from the south to north.Through analysis of the correlation between schistosomiasis and environmental factors, it is found that the climates associated factors include annual average temperature, the annual highest temperature, annual lowest temperature, annual average relative humidity, and sunshine hours.【Conclusions】G1S Spatial Analysis in the domain-wide scale, powerful, strong applications, the law reveals the spatial distribution, and to the indicators of disease for further analysis. A heavy clustering of schistosomiasis was seen, indicating the transmission radius of schistosomiasis is relatively small. The size of transmission radius is associated with the ecological environment of snail (the middle host) and the scope of host's activity. Diffusion of snail research and environmental change on the impact of snail control laws for the important significance of schistosomiasis. Basically defined the distribution of schistosomiasis in Hubei Province and aggregation profile, which is the control of schistosomiasis in Hubei Province has some significance.The results show that schistosomiasis endemic areas with the transfer from south to north trend with time went by. Control of the northern region ecological environment is of positive significance to the control spread of schistosomiasis.