江苏省江宁县气候因素在钉螺分布中的作用

目的　探求钉螺分布与环境气候因素的关系 .方法　收集江宁县 1990 / 1999螺情及同期的气温、降雨量、日照时间等气候环境资料 ,以逐步回归法进行分析 .结果　影响不同流行区钉螺分布的环境因素不同 ,其中江滩型钉螺密度与1月份平均气温正相关 (r=0 .6 6 4 ,P<0 .0 5 ) ,山区型钉螺密度和 3及 10月份日照时间呈负相关 (r分别为 - 0 .710和- 0 .70 3,P均 <0 .0 5 ) ;进行逐步多元回归分析进一步显示 ,江滩型钉螺密度与 1和 2月份的气温存在 Y=- 1.75 2 +0 .392 t1 +0 .2 74 t2 的关系 (其中 t1 ,t2 分别代表 1,2月份的平均气温 ,Y代表钉螺密度 ) ,山区型钉螺密度与 3月份日照时间存在 Y=0 .70 7- 0 .0 0 375 s3关系 (s3为三月份日照 ) .结论　山区型钉螺分布受日照影响较大 ,过强日照不利于钉螺的生长繁殖 ;而江滩型钉螺分布受气温影响较大 ,过低气温亦不利于钉螺的生长繁殖

Climate factors on distribution of snail in Jiangning county in Jiangsu Province

AIM To explore the relationship between the climate factors (including temperature, rainfall and sunshine time) and the density of schistomiasis transmitted snail in Jiangning County. METHODS The snail density and the climate data supervised by Jiangning weather station from 1990 to 2000 were investigated, including the average temperature, rainfall and sunshine every month, and the annual maximum and minimum data. Then the correlation of the snail density and these climate data was explored using the correlation analysis and multivariable liner regression. RESULTS The snail density of marshland was correlated positively with the average temperature of January ( r =0.664, P <0.05) and the snail density of mountain related negatively to the average sunshine of March and October respectively ( r = -0.710 and -0.703, P <0.05). However, the snail density did not relate to the average rainfall and other climatic parameters. By the multivariable regression, we established the equation : for marshland, Y =1.752+0.392 t 1+0.274 t 2 ( Y is the snail density, t 1 and t 2 are the average temperature of January and February every year), and for mountain, Y = 0.707 -0.00375 s 3 ( s 3 is the sunshine of March every year). CONCLUSION The climate factors can affect the density and distribution of schistosomiasis transmitted snail, and different climatic factors play variable roles in different micro enviroment in which the snail survives.