Abstract: Objective　To evaluate the potential risk of transmission of angiostrongyliasis by common freshwater snails in Dali Bai Autonomous Prefecture, Yunnan Province, so as to provide insights into local surveillance of angiostrongyliasis. Methods 　 Common freshwater snails were collected from Dali Bai Autonomous Prefecture, Yunnan Province from March to April, 2020, and identified and bred in laboratory. SD rats were infected with third⁃stage larvae of Angiostrongylus cantonensis that were isolated from commercially available Pomacea canaliculata snails in Dali Bai Autonomous Prefecture, and freshwater snails were infected with the first⁃stage larvae of A. cantonensis that were isolated from the feces of SD rats 39 days post⁃infection at room temperature. The developmental process and morphological characteristics of worms in hosts were observed, and the percentages of A. cantonensis infections in different species of freshwater snails were calculated. Then, SD rats were infected with the third⁃stage larvae of A. cantonensis that were isolated from A. cantonensis⁃infected freshwater snails, and the larval development and reproduction was observed. Results　More than 3 000 freshwater snail samples were collected from farmlands, ditches and wetlands around Erhai Lake in Dali Bai Autonomous Prefecture, and Cipangopaludina chinensis, P. canaliculata, Parafossarulus striatulus, Oncomelania hupensis robertsoni, Galba pervia, Physa acuta, Radix swinhoei, Assiminea spp., Tricula spp. and Bellamya spp. were morphologically identified. A total of 105 commercially available P. canaliculata snails were tested for A. cantonensis infections, and 2 P. canaliculata snails were found to be infected with A. cantonensis, in which the third⁃stage larvae of A. cantonensis were isolated. Ten species of freshwater snails were artificially infected with the third⁃stage larvae of A. cantonensis, and all 10 species of freshwater snails were found to be infected with A. cantonensis, with the highest positive rate of A. cantonensis infections in Bellamya spp. (62.3%, 137/204), and the lowest in C. chinensis (35.5%, 11/31). After SD rats were infected with the third⁃stage larvae of A. cantonensis isolated from different species of freshwater snails, mature adult worms of A. cantonensis were yielded. Conclusions　Multiple species of freshwater snails may serve as intermediate hosts of A. cantonensis under laboratory conditions in Dali Bai Autonomous Prefecture of Yunnan Province. Further investigations on natural infection of A. cantonensis in wild snails in Dali Bai Autonomous Prefecture seem justified.

Key words: Angiostrongylus cantonensis, Freshwater snail, Artificially infection, Dali Bai Autonomous Prefecture

摘要： 目的　评估云南省大理白族自治州常见淡水螺传播广州管圆线虫病的潜在风险，为当地广州管圆线虫病监测提供参考。方法　2020年3—4月，采集云南省大理白族自治州常见淡水螺类，于实验室鉴定、饲养。自大理白族自治州市售福寿螺体内分离广州管圆线虫Ⅲ期幼虫，感染SD大鼠，39 d后于SD大鼠粪便中分离出广州管圆线虫I期幼虫，室温下分别感染各类淡水螺，观察虫体在宿主体内发育及虫体形态，统计不同螺种广州管圆线虫感染率。分离广州管圆线虫感染阳性螺体内广州管圆线虫Ⅲ期幼虫，再次感染SD大鼠，观察该幼虫是否继续发育繁殖。结果　于大理白族自治州农田、沟渠及洱海周边湿地累计采集3 000余只淡水螺样本，经形态学鉴定分别为中国圆田螺、小管福寿螺、纹沼螺、钉螺滇川亚种、小土蜗、尖膀胱螺、椭圆萝卜螺、拟沼螺待定种、拟钉螺待定种和环棱螺待定种等10种螺类。累计对105只市售福寿螺进行了广州管圆线虫感染检测，发现2只感染阳性螺，从中分离出广州管圆线虫Ⅲ期幼虫。以广州管圆线虫Ⅲ期幼虫人工感染淡水螺，发现10种淡水螺均可感染广州管圆线虫，其中环棱螺待定种感染率最高（62.3%，137/204）、中国圆田螺感染率最低（35.5%，11/31）。从各种淡水螺体内分离出广州管圆线虫Ⅲ期幼虫再次感染SD大鼠，均获得发育成熟的广州管圆线虫成虫。结论　在实验室条件下，云南省大理白族自治州多种淡水螺均可作为中间宿主感染广州管圆线虫，建议进一步对该地区野外螺类自然感染广州管圆线虫进行调查。

关键词: 广州管圆线虫, 淡水螺, 人工感染, 大理白族自治州