Abstract: Objective　To compare the effectiveness of loop⁃mediated isothermal amplification (LAMP) assay and microscopic examinations for detection of Schistosoma japonicum infections in Oncomelania hupensis in transmission⁃interrupted regions, so as to provide insights into the optimization of snail surveillance tools in these regions. Methods　Four hilly schistosomiasis⁃endemic villages where transmission interruption was achieved were selected in Heqing County of Yunnan Province as the study villages, including Xinzhuang and Gule villages in hilly regions and Lianyi and Yitou villages in dam regions. Snail survey was performed by means of systematic sampling combined with environmental sampling in July 2018. All captured snails were identified for S. japonicum infections using microscopy. In addition, 10 to 20 snails were randomly sampled from each snail habitat following microscopy, numbered according to environments and subjected to LAMP assay. The positive rate of settings with S. japonicum⁃infected snails was compared among villages. Results　A total of 7 949 living snails were captured from 83 snail habitats in 4 villages, and no S. japonicum infection was detected in snails. There were 22 mixed samples containing 1 786 snails subjected to LAMP assay, and positive LAMP assay was found in 3 mixed samples from 3 snail habitats in 2 dam villages. The positive rates of settings with S. japonicum⁃infected snails were comparable between Lianyi Village (one setting) and Yitou Village (2 settings) (5.89% vs. 14.29%, P = 0.344). However, the overall positive rate of settings with S. japonicum⁃infected snails was significantly higher in dam villages (9.67%, 3/31) than in hilly villages (0) (P = 0.048). Conclusions　LAMP assay is more sensitive to detect S. japonicum infections in O. hupensis than conventional microcopy method, which may serve as a supplementary method for detection of S. japonicum infections in O. hupensis in high⁃risk snail habitats in hilly transmission⁃interrupted regions.

Key words: Oncomelania snail, Loop?mediated isothermal amplification, Transmission interruption, Yunnan Province

摘要： 目的　比较环介导等温扩增技术（LAMP）和镜检法在血吸虫病传播阻断地区检测血吸虫感染性钉螺的效果，为该类地区优化钉螺监测技术提供科学依据。方法　选择云南省鹤庆县达到传播阻断标准的新庄、古乐、邑头、连义4个山丘型血吸虫病流行村作为研究村，其中新庄、古乐为山区村，连义、邑头为坝区村。2018年7月采用系统抽样结合环境抽查法进行钉螺调查，捕获钉螺用解剖镜检法观察血吸虫感染。同时在各有螺环境捡获的钉螺镜检后随机选择10 ~ 20只进行组织提取，按不同环境分别编号，混合后进行LAMP检测。比较不同流行村环境LAMP阳性率差异。结果　4个村共调查83处有螺环境，捕获活螺7 949只，镜检未发现血吸虫感染性钉螺。1 786只钉螺共混合成226管样品进行LAMP检测，在2个坝区村发现LAMP核酸阳性3管，分布在2个村3处有螺环境，其中连义村1处环境，环境阳性率5.89%；邑头村2处环境，环境阳性率14.29%，2个坝区村环境阳性率差异无统计学意义（P = 0.344），但坝区村环境总阳性率（9.67%，3/31）高于山区村（0）（P = 0.048）。结论　LAMP技术检测血吸虫感染性钉螺较传统解剖镜检法更敏感，可作为山丘型血吸虫病传播阻断流行区高危有螺环境钉螺检测方法的一种补充。

关键词: 钉螺, 环介导等温扩增技术, 传播阻断, 云南省