Abstract:

Objective Objective To evaluate the field molluscicidal effect of 5% niclosamide ethanolamine granules，so as to provide a novel Oncomelania hupensis snail control approach for emergency treatment of high?risk settings. Methods Methods Snail control tests with spraying of 5% niclosamide ethanolamine granules were conducted in two settings of 2 counties，and the dose?，time? and setting?specific field molluscicidal effects were tested. Results Results In the small?scale setting，spraying of 5% niclosamide ethanolamine granules at doses of 30，40 and 50 g/m2 resulted in 54.55%，68.41% and 73.45% 1?day snail mortality，57.27%，68.59% and 80.28% 3?day snail mortality，and 63.49%，77.58% and 85.55% 7?day snail mortality，respectively，and no significant dif? ferences were detected in 1? and 3?day snail mortality caused by spraying of 5% niclosamide ethanolamine granules at doses of 30 and 40 g/m2 （all P > 0.05），while significant difference was found in the 7?day snail mortality（χ2 = 4.549，P < 0.05） . In ad? dition，spraying of 5% niclosamide ethanolamine granules at doses of 40 and 50 g/m2 resulted in comparable 1?，3? and 7?day snail mortality（all P > 0.05） . In the large?scale setting，spraying of 5% niclosamide ethanolamine granules at a dose of 40 g/m2 resulted in 85.29% and 87.70% 3?day snail mortality，83.89% and 91.02% 7?day snail mortality，and 83.41% and 91.84% 15? day snail mortality in the environment ? cleaning group and non ? cleaning group，respectively. The overall snail mortality was 90.02% in the environment?cleaning group 3 to 15 days after spraying，which was significantly higher than that（84.28%）in the non?cleaning group（χ2 = 9.950，P < 0.05） . After 15 days of spraying with 5% niclosamide ethanolamine granules at a dose of 40 g/m2 ，the densities of living snails reduced from 19.90 and 19.83 snails/0.1 m2 to 0.60 and 2.60 snails/0.1 m2 in the environ? ment?cleaning group and non?cleaning group，with 96.98% and 86.89% reductions，respectively. Conclusion Conclusion The appropriate dose of 5% niclosamide ethanolamine granules is 40 g/m2 for snail control in the field，and environment cleaning of vegetation with a height of more than 50 cm may improve the molluscicidal efficacy.

Key words: Schistosomiasis, Oncomelania snail；5% niclosamide ethanolamine granules；Molluscicidal efficacy；Emergen? cy treatment； Effect evaluation, Jiangsu Province

摘要：

目的 目的 通过现场试验获得5%杀螺胺颗粒剂现场应用的技术指标， 为血吸虫感染高危环境应急处置提供钉螺控制新技术。 方法 方法 在扬州市邗江区 （小现场） 和仪征市 （大现场） 各选择1个环境进行5%杀螺胺颗粒剂喷撒灭螺试验， 比较不同剂量、 不同时间和是否环境清障条件下的杀螺效果。 结果 结果 小现场试验显示， 30、 40、 50 g/m2 5%杀螺胺颗粒剂喷撒1、 3 d和7 d后， 钉螺死亡率分别为54.55%、 68.41%和73.45%， 57.27%、 68.59%和80.28%， 63.49%、 77.58%和85.55%； 其中30 g/m2 与40 g/m2 剂量组在喷撒后1、 3 d钉螺死亡率差异均无统计学意义 （P均 > 0.05）， 喷撒后7 d钉螺死亡率差异有统计学意义 （χ2 = 4.549， P < 0.05）， 40 g/m2 与50 g/m2 剂量组喷撒后1、 3 d和7 d钉螺死亡率差异均无统计学意义 （P均 > 0.05）。大现场试验显示， 未清障和清障环境采用40 g/m2 5%杀螺胺颗粒剂喷撒3、 7 d和15 d后钉螺死亡率分别为 85.29%、 83.89%、 83.41%和87.70%、 91.02%、 91.84%； 清障组喷撒后3～15 d钉螺总体死亡率为90.02%， 显著高于未清障组 （84.28%）（χ2 = 9.950， P < 0.05）； 清障与未清障组喷撒15 d后活螺密度分别由19.90只/0.1 m2 和19.83只/0.1 m2 下降至0.60只/0.1 m2 和2.60只/0.1 m2 ， 分别下降了96.98%和86.89%。 结论 结论 5%杀螺胺颗粒剂现场喷撒灭螺适宜剂量为40 g/m2 ， 对环境中高于50 cm的植被清障将提高灭螺效果。

关键词: 血吸虫病； 钉螺； 5%杀螺胺颗粒剂； 灭螺效果； 应急处置； 效果评价； 江苏省