关键词: 椎实螺, 毛毕吸虫, 中间宿主, 耳萝卜螺, 椭圆萝卜螺

Abstract: Objective To investigate species,infection and breeding regulation of the intermediate host ofTrichobilharziain the Huaihe River System. Methods June of 2002-May of 2003,the snails Lymnaeidae were collected in Yaohe River,Gaotanghu Lake,Jaoganghu Lake and Huajiahu Lake of the branch of the Huaihe River,Huainan City,Anhui Province. Collected snails were fed and observed. The cercariae were examined from the snails mounted directly on a glass slide collected on the spot,and were collected by Shade Drop Bottle to infect ducklings and volunteer skin. The eggs and imagoes were separated from infected ducklings. ResultsRadix swinhoeiand Radix auriculariawere found as the intermediate host of Trichobilharziain the basin and the natural infection rates,were 0.65% ,0.21% 、0.07%-0.26% in April,May,August,September and October respectively,which were significantly different (χ²=32.78,P <0.001;χ²=26.73,P<0.01). BothR.swinhoeiandR.auriculariabecame active in the middle of February,gradually hid into soil to overwinter in the late October and brought up 3 generations per year. Conclusion The results show that the both snails widely dispersed on Huaihe riverside and were main intermediate hosts of Trichobiharziacausing cercarial dermatitis in the Huaihe River System,and the results also offer references to control and wipe out these intermediate hosts.