Optimizing low-technology metofluthrin emanators to extend active ingredient release while maximizing protection against malaria transmission

优化低技术含量的甲氧氟菊酯喷射器，以延长活性成分的释放时间，同时最大限度地防止疟疾传播

• 批准号: MR/N027442/1
• 负责人: Gerry Killeen
• 金额: $ 12.64万
• 依托单位: Liverpool School of Tropical Medicine
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FN027442%2F1
• 关键词: Optimizing; low; technology; metofluthrin; emanators

We recently developed a low-technology emanator consisting of commonly available Hessian sacking impregnated with the widely-used volatile pyrethroid transfluthrin, which is slowly released into the air as a vapour. These emanators protected humans against behaviourally and physiologically resistant Anopheles arabiensis indoors and outdoors for over 2 years and killed the vast majority of mosquitoes that succeeded in feeding on protected humans. The disadvantage of transfluthrin is its relatively high melting point, which limits its vapour pressure and efficacy outside of low-altitude equatorial settings with very high night time temperatures. Fortunately, a similarly safe volatile pyrethroid called metofluthrin is also available from generic sources, which has a lower melting point so it remains volatile across the full range of temperatures relevant to malaria transmission.We therefore propose to repeat dose-optimization for this emanator prototype with metofluthrin, rather than transfluthrin, using a range of thicknesses of diffusion-retarding plastic coatings. Our primary objective is to identify the minimum dose, and optimal coating thickness at that dose, which confers at least 80% protection against exposure to biting An. arabiensis, as well as An. gambiae and An. funestus, for at least one year. Our secondary objective is to demonstrate that predicted maximum cost per year of protection is comparable with those for long-lasting insecticidal nets.If both objectives are achieved, this early phase study will be followed by an application to conduct the main study: a community-randomized controlled trial to assess impact upon malaria incidence among both users and non-users, supplemented with participatory social science studies of end-user perceptions. Both studies will be conducted in a relatively high altitude (1100m) region of west Kenya with moderate temperatures.

我们最近开发了一种低技术的散发器，包括常用的黑森麻袋浸渍广泛使用的挥发性拟除虫菊酯四氟菊酯，这是缓慢释放到空气中的蒸汽。这些散发器在室内和室外保护人类免受行为和生理抗性阿拉伯按蚊的侵害超过2年，并杀死了绝大多数成功以受保护人类为食的蚊子。四氟菊酯的缺点是其熔点相对较高，这限制了其在夜间温度非常高的低海拔赤道环境之外的蒸汽压和功效。幸运的是，一种名为甲氧氟菊酯的类似安全的挥发性拟除虫菊酯也可以从仿制药来源获得，它具有较低的熔点，因此在与疟疾传播相关的整个温度范围内保持挥发性。因此，我们建议使用甲氧氟菊酯对这种散发器原型重复剂量优化，而不是使用四氟菊酯，使用一系列厚度的扩散阻滞塑料涂层。我们的主要目标是确定最小剂量，以及在该剂量下的最佳涂层厚度，其赋予至少80%的保护免受暴露于叮咬An。arabiensis，以及An. gambiae和An.至少一年的时间。我们的第二个目标是证明预计的每年最高保护成本与长效驱虫蚊帐的成本相当，如果这两个目标都实现了，在这一早期阶段研究之后，将申请进行主要研究：一项社区随机对照试验，评估对使用者和非使用者疟疾发病率的影响，并辅之以关于最终使用者看法的参与性社会科学研究。这两项研究都将在肯尼亚西部相对高海拔（1100米）的地区进行，气温适中。