Objective: To investigate the effectiveness and cost of 50% and 80% wettable powder of niclosamide ethanolamine salt (NESWP) and 26% metaldehyde and niclosamide suspension concentrate (MNSC) in hilly schistosomiasis-endemic regions, so as to provide insights into the selection of chemical molluscicides in hilly regions.
Methods: In September 2020, a wasteland in Guanshanqiao Village, Yanrui Township, Yushan County of Jiangxi Province was selected as the experimental region, which was sectioned into five blocks and defined as four experimental groups (A1, A2, B, C) and a blank control group (D). 80% NESWP were given at doses of 1 g/m2 and 1.5 g/m2 in groups A1 and A2 using the spraying method, 50% NESWP was given at a dose of 2 g/m2 in Group B using the spraying method, and 26% MNSC was at a dose of 4 g/m2 in Group C using the spraying method, while no chemical treatment was given in Group D. Snail survey was performed using a systematic sampling method before chemical treatment and 1, 3, 7 d and 15 d post-treatment to examine the molluscicidal effect, and all molluscicidal costs were estimated to calculate the cost of chemical treatment per 1 m2 and the cost of the reduction in the mean density of living snails per 1%.
Results: The highest mortality of snails was 78.95% and the lowest density of living snails was 0.2388 snails/0.1 m2 in the experimental groups within 7 d of chemical treatment, and the highest mortality of snails was 94.74% and the lowest density of living snails was 0.058 0 snails/0.1 m2 7 d post-treatment. There were no significant differences in the snail mortality among the A1, A2, B and C groups 1 (χ2 = 2.250, P > 0.05), 3 (χ2 = 1.779, P > 0.05) or 15 d post-treatment (χ2 = 2.286, P > 0.05), while a significant difference was detected in the snail mortality among the four groups 7 d post-treatment (χ2 = 7.990, P = 0.046). In addition, there were no significant differences in the snail mortality between A1 and A2 groups 1 (χ2 = 0.724, P > 0.05), 3 (χ2 = 0.584, P > 0.05), 7 (χ2 = 0.400, P > 0.05) or 15 d post-treatment (χ2 = 0.251, P > 0.05). The costs of chemical treatment per 1 m2 were 0.58, 0.60, 0.64 Yuan and 0.73 Yuan in groups A1, A2, B and C, and the costs of the mean density of living snail per 1% reduction were 19.29, 20.44, 21.68 Yuan and 23.53 Yuan in groups A1, A2, B and C, respectively.
Conclusions: 80% NESWP shows a high molluscicidal efficacy and low cost in hilly schistosomiasis-endemic regions.
［摘要］ 目的 分析 50% 和 80% 杀螺胺乙醇胺盐可湿性粉剂及 26% 四聚杀螺胺悬浮剂在山丘型流行区的应用效果与成本, 为该类流行区选择灭螺药物提供科学依据。方法 2020 年 9 月选择江西省玉山县岩瑞镇关山桥村一片荒田为实验区, 分成 5 个区块, 设 4 个实验组 (A1、A2、B、C 组) 和空白对照组 (D 组), 其中 A1 组和 A2 组分别喷洒 1 g/m2 和 1.5 g/m2 80% 杀螺胺乙醇胺盐可湿性粉剂, B 组喷洒 2 g/m2 50% 杀螺胺乙醇胺盐可湿性粉剂、C组喷洒 4 g/m2 26% 四聚杀螺胺乙醇胺悬浮剂进行灭螺, D组不施用任何灭螺药物。灭螺前及灭螺后1、3、7、15 d, 采用系统抽样法查螺, 观察药物灭螺效果; 统计各项灭螺费用, 计算每组 1 m2 灭螺成本及活螺平均密度每下降 1% 的成本。结果 实验组施药7 d内, 钉螺死亡率最高可达 78.95%, 活螺密度最低可降至 0.238 8 只/0.1 m2; 7 d 后, 钉螺死亡率最高可达 94.74%, 活螺密度最低可降至 0.058 0只/0.1 m2; 施药后 1、3 d和15 d, A1、A2、B 组和C组钉螺死亡率差异无统计学意义 (χ21d = 2.250、χ23d = 1.779、χ215d = 2.286, P 均＞ 0.05), 施药后7 d, 组间差异有统计学意义 (χ27d = 7.990, P = 0.046)。A1组和A2组在施药后1、3、7、15 d钉螺死亡率差异均无统计学意义 (χ21d = 0.724、χ23d = 0.584、χ27d = 0.400、χ215d = 0.251, P 均＞ 0.05)。A1、A2、B组和C组平均每1 m2灭螺成本分别为0.58、0.60、0.64元和0.73元, 各组活螺平均密度每下降1%的成本分别为19.29、20.44、21.68元和23.53元。结论 在山丘型流行区使用80%杀螺胺乙醇胺盐可湿性粉剂灭螺成本较低、效果较好。.
Keywords:
26% metaldehyde and niclosamide suspension concentrate; 50% wettable powder of niclosamide ethanolamine salt; 80% wettable powder of niclosamide ethanolamine salt; Cost-effectiveness; Hilly region;