输入性福寿螺传播广州管圆线虫的潜能研究

目的研究广州管圆线虫对福寿螺和褐云玛瑙螺感染性差异,阐述输入性福寿螺在中国作为广州管圆线虫中间宿主传播广州管圆线虫的潜能。方法生态学调查比较福寿螺和褐云玛瑙螺生存环境的差异及其在中国目前的地理分布,采集不同地理环境下福寿螺和褐云玛瑙螺分析自然环境下广州管圆线虫幼虫的感染率与感染度,同时观察自然环境下野生鼠感染广州管圆线虫的情况;在相同的条件下,用广州管圆线虫I期幼虫感染阴性的福寿螺和褐云玛瑙螺,观察福寿螺和褐云玛瑙螺在实验室的感染差异。结果对调查点发现的螺类检查发现,自然条件下福寿螺的感染率和感染度均低于褐云玛瑙螺,发现螺重与螺感染度呈正相关,大于20 g福寿螺平均感染度高于20 g以下的螺,差异有统计学意义(P0.01);阳性螺孳生地捕获三种鼠,解剖检查发现广州管圆线虫总感染率为9.24%(22/238),褐家鼠的感染率高于黄胸鼠(P0.05),并且雌鼠的感染率显著高于雄鼠(P0.05);两种螺类在实验室人工感染条件下感染率和感染度比较差异均无统计学差异。结论在自然和实验室条件下褐云玛瑙螺、福寿螺对广州管圆线虫均易感,褐云玛瑙螺和福寿螺在自然环境条件下其感染率表现不同。福寿螺在我国适生环境广泛,长江以南均有分布,具备将广州管圆线虫从华南地区扩散到长江以南的潜能,福寿螺的扩散可导致我国广州管圆线虫流行区域的扩大。

Potential of imported Pomacea canaliculate transmitting Angiostrongylus cantonensis in China

Objective To compare the Angiostrongylus cantonensis infectivity difference between Pomacea canaliculate and Achatana fulica,and elaborate the potential of the imported P.canaliculate transmitting A.cantonensis.Methods Ten investigation sites were chosen to collect the snails which were further identified and checked for the infection ofA.cantonensis larva in the laboratory.The wild rats were also captured for examination of the A.cantonensis infections in the epidemic areas.Fifty P.canaliculate and A.fulica snails raised in the laboratory were challenged with larva stage Ⅰ of A.cantonensis in the rat feces under the same conditions.Results The infection rate and intensity ofA.cantonensis in P.canaliculate were both lower than those in A.fulica under the natural conditions.The average infection intensity of P.canaliculate with snail weight over 20 g was significantly higher than that of P.canaliculate with snail weight under 20 g (P＜0.01).Three species of rats were captured in the areas epidemic with A.cantonensis,and the dissection and anatomical study revealed 9.24％(22/238) of infection rate among all the captured rats.Rattus norvegicus had a significantly higher infection rate compared to Rattusflavipectus,and the infection rate in the female rats was higher than that in the male rats with statistical significance.P.canaliculate and A.fulica showed a comparable infection rate and intensity when infected with larva stage Ⅰ of A.cantonensis under the same laboratory conditions.Conclusion P.canaliculate and A.fulica are susceptible to A.cantonensis both in the natural and the laboratory conditions.With the wide area in the south of Yangtze River adapted for P.canaliculate,there is a great possibility for A.cantonensis to spread from South China to other areas also suitable for P.canaliculate.