London School of Hygiene & Tropical Medicine, London, United Kingdom.
Kilimanjaro Christian Medical University College, Moshi, Kilimanjaro, Tanzania.
PLoS One. 2021 Mar 3;16(3):e0248026. doi: 10.1371/journal.pone.0248026. eCollection 2021.
Novel chemistry for vector control is urgently needed to counter insecticide resistance in mosquitoes. Here a new meta-diamide insecticide, broflanilide (TENEBENALTM), was evaluated in East African experimental huts in Moshi, northern Tanzania. Two consecutive experimental hut trials with broflanilide 50WP were conducted; the first evaluating the efficacy of three concentrations, 50 mg/m2, 100 mg/m2, and 200 mg/m2 using a prototype formulation, and the second trial evaluating an improved formulation. The IRS treatments were applied on both mud and concrete surfaces and efficacy was monitored over time. The mortality, blood-feeding inhibition and exiting behaviour of free-flying wild mosquitoes was compared between treatment arms. Additionally, cone assays with pyrethroid-susceptible and resistant mosquito strains were conducted in the huts to determine residual efficacy. The first trial showed a dosage-mortality response of the prototype formulation and 3-8 months of residual activity, with longer activity on concrete than mud. The second trial with an improved formulation showed prolonged residual efficacy of the 100 mg/m2 concentration to 5-6 months on mud, and mosquito mortality on the concrete surface ranged between 94-100% for the full duration of the trial. In both trials, results with free-flying, wild Anopheles arabiensis echoed the mortality trend shown in cone assays, with the highest dose inducing the highest mortality and the improved formulation showing increased mortality rates. No blood-feeding inhibition or insecticide-induced exiting effects were observed with broflanilide. Broflanilide 50WP was effective against both susceptible and pyrethroid-resistant mosquito strains, demonstrating an absence of cross resistance between broflanilide and pyrethroids. The improved formulation, which has now been branded VECTRONTM T500, resulted in a prolonged residual efficacy. These results indicate the potential of this insecticide as an addition to the arsenal of IRS products needed to maintain both control of malaria and resistance management of malaria-transmitting mosquitoes.
需要新的化学药剂来控制病媒，以应对蚊子对杀虫剂的抗药性。本文评价了一种新型拟除虫菊酯杀虫剂溴氟虫酰胺（TENEBENALTM）在坦桑尼亚北部莫希的东非实验小屋中的效果。进行了两次连续的溴氟虫酰胺 50WP 实验小屋试验；第一次试验评估了三种浓度（50mg/m2、100mg/m2 和 200mg/m2）的功效，使用原型配方；第二次试验评估了改进后的配方。在泥墙和混凝土表面都进行了 IRS 处理，并随着时间的推移监测功效。在处理臂之间比较了自由飞行的野生蚊子的死亡率、吸血抑制和退出行为。此外，还在小屋中进行了带有拟除虫菊酯敏感和抗性蚊株的锥形测定，以确定残留功效。第一次试验表明原型配方具有剂量-死亡率反应，3-8 个月的残留活性，在混凝土上的活性比泥墙上长。第二次试验使用改进后的配方，100mg/m2 浓度在泥墙上的残留效果延长至 5-6 个月，在整个试验期间，在混凝土表面上的蚊子死亡率在 94-100%之间。在这两项试验中，与自由飞行的野生疟蚊的死亡率趋势相符，最高剂量诱导最高死亡率，改进后的配方显示出更高的死亡率。在溴氟虫酰胺处理中未观察到吸血抑制或昆虫诱导的退出作用。溴氟虫酰胺 50WP 对敏感和拟除虫菊酯抗性蚊株均有效，表明溴氟虫酰胺与拟除虫菊酯之间不存在交叉抗性。现已注册品牌 VECTRONTM T500 的改进配方具有延长的残留功效。这些结果表明，该杀虫剂具有作为 IRS 产品的补充的潜力，需要这些产品来维持疟疾的控制和抗疟传病蚊的管理。
