深圳环境因素对曼氏血吸虫中间宿主藁杆双脐螺的分布影响

Impact of environmental factors on distribution of Schistosoma mansoni intermediate host Biomphalaria straminea in Shenzhen

目的藁杆双脐螺是传播曼氏血吸虫病重要的中间宿主,环境因素的变化对该螺的分布与扩散产生很大影响,研究藁杆双脐螺的空间分布特征及其影响因素,为预测该螺的孽生分布、曼氏血吸虫病传播风险监测等提供科学依据。方法本文在获取深圳市各区河流段的藁杆双脐螺密度数据的基础上,运用空间自相关、空间统计分析等方法,分析了深圳市各区河流段的藁杆双脐螺密度的空间分布特征以及与环境因素的相关性。结果深圳市螺的分布有较强的聚集性,其密度高低受环境因素影响.螺很少出现在水质极好或极差的环境中,主要分布在地势起伏小且坡度在0~9之间、植被为3~9的环境中;受海洋性气候影响,区域温度、湿度的差异对螺分布影响较小。且各环境因素对螺密度影响差异有统计学意义,环境相关性有坡度>植被>湿度>水质>温度。结论分析结果显示藁杆双脐螺的分布特征与环境因素关系密切。环境因素影响其生存条件,并与其分布密度也有一定的相关性。

Objective Biomphalaria straminea is an important intermediate host of Schistosoma mansoni, and thedistribution and diffusion of it are greatly affected by environmental factors. This study explores the characteristics of spatialdistribution of B. straminea and influencing factors, so as to provide the evidence for forecasting the distribution of B. stramineabreeding and monitoring the risk of schistosomiasis mansoni spreading. Methods The data of B. straminea density of riversacross Shenzhen administrative area were collected. The characteristics of spatial distribution and the correlation withenvironmental factors were analyzed by the spatial autocorrelation and statistics. Results There was an intense aggregation ofthe snails＇ distribution, and its density levels were affected by environmental factors. There were no snails when the waterquality was excellent or poor. The snails were mainly distributed in areas that the slope was from 0 to 9 and the vegetation indexwas between 3 and 9（poor-good）. The regional differences of temperature and humidity had little effect on the snails＇ distribution. Finally, the influence of environmental factors on snail density was different, that was slopevegetation indexhumiditywater qualitytemperature. Conclusion The distribution of B. straminea is obviously associated with theenvironmental factors, which have the impact on the living condition, density and distribution of B. straminea.