血吸虫病流行的地理信息系统分析

Geographic information system analysis of schistosomiasis transmission

目的应用地理信息系统（GIS）分析血吸虫病的空间分布和流行趋势。方法收集安徽省铜陵县2004年和2008年血吸虫病抽样调查资料，建立GIS数据库，应用ArcGIS9．3空间分析扩展模块中的反距离加权插值法对钉螺面积、钉螺阳性率和人群感染率差值进行空间分析。结果2004与2008年螺感染率差值图显示，铜陵县江心洲南部的老洲乡螺阳性率显著下降，而江心洲北部无显著下降趋势，铜陵县山丘内陆地区螺感染率也无明显变化。螺面积差值图显示近年来铜陵县的有螺面积无显著变化趋势。人群感染率差值图显示江心洲的大部分区域人群感染率下降，山丘内陆地区无显著下降趋势。结论应用GIS制作的差值空间分布图能直观地揭示和分析血吸虫病的疫情变化，结果显示全面实施“以机代牛”、“改水改厕”等传染源控制为主的措施后，钉螺阳性率和人群感染率明显下降，不失为控制洲岛型血吸虫病流行的有效措施。

Objective To analyze the spatial distribution and trends of schistosomiasis by Geographic Information Systems （GIS）. Methods The data of sampling surveys on schistosomiasis in 2004 and 2008 in Tongling county of Aabui province were collected and the databases of GIS were set up. The spatial status of snail infection rate variance, snail habitat area variance and human infection rate variance were analyzed with the method of GIS IDW（ inverse distance weighted） in the spatial analyst extension of AreGIS 9.3. Results The snail infection rate variance map between 2004 and 2008 showed the positive rate of Laozhou village in Jiangxin-island decreased, while there was no significant downward trend in northern part of the Jiangxiu-island and in the inland hilly areas of Tongling county. Snail habitat area variance map showed no significant changes in Tongling county in recent years. Human infection rate variance map showed the infection rate declined in most regions of the Jiangxin-island, while there was no significant decline trend in inland hilly areas of Tangling county. Conclusions Variance maps produced by GIS can visually reveal the endemic trend of schistosomiasis. The snail positive rate and the human infection rate of Laozhou village are descendent after implementing the comprehensive measures with emphasis on infectious source control such as ＂Replacing cattle by machine＂ and ＂Reconstrncting water supply and lavatory＂, indicating that the measures with focus on infectious source control are effective for schistosomiasis control in islet endemic regions.