Abstract: Objective To classify and grade the environments with Oncomelania hupensis snails inside embankment in marsh? land and lake areas，so as to improve the work efficiency and realize the systematic management. Methods The schistosomiasis endemic area Liaodi and Xiongdi villages in Jiangling County，Hubei Province were selected as the experiment villages，and the environments with snails in the two villages were divided into sections with a length of 500 m，then the snail situation were sur? veyed by the systematic sampling method with 10 m and 50 m a frame respectively. The environments were classified according to the discovery of infected snails and wild fecal contamination，and the numbers of sites with snails and their areas in different class? es were recorded. Meanwhile，the data of sites with infected snails in Jingzhou City during the recent 5 years were collected and graded according to the average density of snails，so as to discuss the correlativity between the grades of environments with snails and the numbers of sites with infected snails and the occurrence rate of frames with snails. Results There were 1 967 sites with in? fected snails in Jingzhou City during the recent 5 years，and there was a positive correlation between the grades of environments with snails and the occurrence rate of frames with snails（rs= 0.77，P＜0.01），when the grade was 5，the constituent ratio of num? bers of sites with infected snails was 3.1%，and when the grade was 2-3，the ratio raised to 56.3%. There were 39 sites with snails in the two villages，the Class 1，2 and 3 environments included 1， 18 and 20 sites，with the areas of 1 080， 51 640m2 and 41 220 m2 ， respectively. There were no statistically significant difference between the grades divided by snail survey with 10 m and 50 m a frame（χ2 ＝4.667，P＞0.05），but the time?consuming of the former was 3 times of the latter. Conclusions The classification and grading of the environments with snails inside embankment in marshland and lake areas can master the key point of the snail survey. The subsection and setting frames at a suitable distance can save time and manpower，improve work efficiency，as well as understand the distribution of snail status of the environment with snails，which can realize the sort management of the snail envi? ronments inside embankment.

Key words: Oncomelania hupensis；Classification and grading；Environment with snail；Inside embankment；Marshland and lake area

摘要： 目的 目的 对湖沼地区垸内有螺环境进行分类定级， 以提高查螺工作效率， 实现有螺环境分类管理。方法 方法 选择湖 北省湖沼型血吸虫病流行区江陵县廖堤村和熊堤村为试验村， 对其有螺环境按500 m为段进行分段， 采用系统抽样法， 以 50 m和10 m设框分别对两村进行调查。按是否发现感染性螺点、 有无野粪污染对有螺环境进行分类， 统计两村各类有螺 环境处数及面积。收集荆州市近5年来感染性螺点数据， 按钉螺平均密度对有螺环境进行分级， 探索有螺环境级别与感染 性螺点数和有螺框出现率之间的关系。结果 结果 荆州市近5年来共有1 967处感染性螺点， 有螺环境级别与有螺框出现率呈 正相关关系 （rs= 0.77，P＜0.01）， 有螺环境为5级时， 感染性螺点数构成比为3.1%， 有螺环境为2～3级， 感染性螺点数构成 比达56.3%。两试验村共有39处有螺环境， 1、 2、 3类环境分别为1、 18、 20 处， 面积分别为1 080、 51 640、 41 220 m2 。50 m设 框与10 m设框查出的有螺环境分级差异无统计学意义 （χ2 ＝4.667，P＞0.05）， 但后者查螺用时约为前者的3倍。结论 结论 对垸内有螺环境采用分类定级的查螺模式， 可掌握查灭螺重点。分段定框查螺可节省查螺时间和人力资源， 提高工作效 率， 同时也可掌握有螺环境的螺情分布现状， 从而有利于实现对垸内有螺环境分类管理。

关键词: 钉螺； 分类定级； 有螺环境； 垸内； 湖沼地区