Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America.
PLoS Negl Trop Dis. 2021 Jan 26;15(1):e0009036. doi: 10.1371/journal.pntd.0009036. eCollection 2021 Jan.
In the absence of vaccines or drugs, insecticides are the mainstay of Aedes-borne disease control. Their utility is challenged by the slow deployment of resources, poor community compliance and inadequate household coverage. Novel application methods are required.
A 10% w/w metofluthrin "emanator" that passively disseminates insecticide from an impregnated net was evaluated in a randomized trial of 200 houses in Mexico. The devices were introduced at a rate of 1 per room and replaced at 3-week intervals. During each of 7 consecutive deployment cycles, indoor resting mosquitoes were sampled using aspirator collections. Assessments of mosquito landing behaviours were made in a subset of houses. Pre-treatment, there were no differences in Aedes aegypti indices between houses recruited to the control and treatment arms. Immediately after metofluthrin deployment, the entomological indices between the trial arms diverged. Averaged across the trial, there were significant reductions in Abundance Rate Ratios for total Ae. aegypti, female abundance and females that contained blood meals (2.5, 2.4 and 2.3-times fewer mosquitoes respectively; P<0.001). Average efficacy was 60.2% for total adults, 58.3% for females, and 57.2% for blood-fed females. The emanators also reduced mosquito landings by 90% from 12.5 to 1.2 per 10-minute sampling period (P<0.05). Homozygous forms of the pyrethroid resistant kdr alleles V410L, V1016L and F1534C were common in the target mosquito population; found in 39%, 24% and 95% of mosquitoes collected during the trial.
CONCLUSIONS/SIGNIFICANCE: This is the first randomized control trial to evaluate the entomological impact of any volatile pyrethroid on urban Ae. aegypti. It demonstrates that volatile pyrethroids can have a sustained impact on Ae. aegypti population densities and human-vector contact indoors. These effects occur despite the presence of pyrethroid-resistant alleles in the target population. Formulations like these may have considerable utility for public health vector control responses.
在缺乏疫苗或药物的情况下，杀虫剂是控制蚊媒疾病的主要手段。但由于资源配置缓慢、社区配合度差以及家庭覆盖范围不足，其效用受到了挑战。需要新的应用方法。
在墨西哥进行的一项 200 户随机试验中，评估了一种 10% w/w 氯菊酯“散发器”，它从浸渍过的网片中被动地传播杀虫剂。以每个房间 1 个的速度引入这些设备，并每 3 周更换一次。在连续 7 个部署周期中的每一个周期，都使用吸气器收集室内休息的蚊子进行样本采集。在一小部分房屋中进行了蚊子降落行为评估。在治疗前，对照组和实验组的埃及伊蚊指数没有差异。在氯菊酯释放后，试验组之间的昆虫学指数立即出现差异。整个试验平均而言，总埃及伊蚊、雌性数量和含有血餐的雌性数量的丰度比率都有显著降低（分别减少 2.5、2.4 和 2.3 倍；P<0.001）。总成虫的平均效力为 60.2%，雌成虫为 58.3%，吸血雌成虫为 57.2%。散发器还将蚊子的降落率从 12.5 只/10 分钟的采样期降低了 90%，降至 1.2 只（P<0.05）。目标蚊群中常见的是对拟除虫菊酯抗性 kdr 等位基因 V410L、V1016L 和 F1534C 的纯合形式，在试验期间收集的蚊子中，分别有 39%、24%和 95%携带这些基因。
结论/意义：这是第一项评估挥发性拟除虫菊酯对城市埃及伊蚊的昆虫学影响的随机对照试验。它表明，挥发性拟除虫菊酯可以对埃及伊蚊种群密度和室内人类与蚊子的接触产生持续影响。这些效果发生在目标种群中存在拟除虫菊酯抗性等位基因的情况下。像这样的制剂可能对公共卫生控制蚊子的应对措施具有相当大的效用。
