Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania.
Mosquito Section, Division of Livestock and Human Health Disease Vector Control, Tropical Pesticides Research Institute, P.O. Box 3024, Arusha, Tanzania.
Malar J. 2019 Oct 1;18(1):335. doi: 10.1186/s12936-019-2973-x.
The decline in malaria cases and vectors is major milestone in fighting against malaria. The efficacy of MAGNet long-lasting insecticidal nets (MAGNet LLIN), an alpha-cypermethrin incorporated long-lasting net, with the target dose ± 25% of 5.8 g active ingredient (AI)/kg (4.35-7.25 g AI/kg) was evaluated in six veranda-trap experimental huts in Muheza, Tanzania against freely flying wild population of Anopheles funestus.
MAGNet LLINs were tested against wild, free-flying, host-seeking An. funestus mosquitoes over a period of 6 weeks (total of 36 nights in the huts). MAGNet LLIN efficacy was determined in terms of mosquito mortality, blood-feeding inhibition, deterrence, induced exiting, personal protection, and insecticidal killing over 20 washes according to WHO standardized procedures. Efficacy was compared with reference to a WHOPES recommended approved LLINs (DuraNet) and to a net conventionally treated (CTN) treated with alpha-cypermethrin at WHO-recommended dose and washed to just before cut-off point. The efficacy of MAGNet was evaluated in experimental huts against wild, free-flying, pyrethroid-resistant An. funestus. The WHO-susceptibility method was used to detect resistance in wild Anopheles exposed to 0.75% permethrin. Mosquito mortality, blood-feeding inhibition and personal protection were compared between untreated nets and standard LLINs. Blood-feeding rates were recorded and compared between the 20 times washed; blood-feeding rates between 20 times washed MAGNet LLIN and 20 times washed WHOPES-approved piperonyl butoxide (PBO)/pyrethroid were not statistically different (p > 0.05).
The results have evidently shown that MAGNet LLIN provides similar blood-feeding inhibition, exophily, mortality, and deterrence to the standard approved LLIN, thus meeting the WHOPES criteria for blood feeding. The significantly high feeding inhibition and personal protection over pyrethroid-resistant An. funestus recorded by both unwashed and 20 times washed MAGNet compared to the unwashed DuraNet, the WHOPES-approved standard pyrethroid-only LLIN provides proof of MAGNet meeting Phase II WHOPES criteria for a LLIN.
Based on this study, MAGNet has been shown to have a promising impact on protection when 20 times washed against a highly resistant population of An. funestus.
疟疾病例和病媒数量的下降是抗击疟疾的重要里程碑。MAGNet 长效杀虫蚊帐（MAGNet LLIN）的功效得到了评估，该蚊帐含有α-氯氰菊酯，目标剂量为 5.8 克有效成分（AI）/公斤（4.35-7.25 克 AI/公斤），在坦桑尼亚穆赫扎的六个阳台诱捕实验棚中，对自由飞行的野生冈比亚按蚊种群进行了测试。
在 6 周的时间里（总共在棚内 36 晚），用 MAGNet LLIN 对野生、自由飞行、寻找宿主的冈比亚按蚊进行了测试。根据世界卫生组织（WHO）标准化程序，按照 WHO 推荐的标准，以蚊死亡率、吸血抑制、驱避、诱导退出、个人保护和 20 次洗涤后的杀虫效果来衡量 MAGNet LLIN 的功效。与 WHOPES 推荐的经批准的长效蚊帐（DuraNet）和用 WHO 推荐剂量处理并洗涤至截止点的常规处理（CTN）进行比较。在实验棚中，用 MAGNet 对野生、自由飞行、对拟除虫菊酯有抗性的冈比亚按蚊进行了评估。采用世界卫生组织（WHO）敏感性方法检测暴露于 0.75%氯菊酯的野生疟蚊的抗药性。对未经处理的蚊帐和标准长效蚊帐之间的蚊死亡率、吸血抑制和个人保护进行了比较。记录并比较了 20 次洗涤后的吸血率；20 次洗涤后的 MAGNet LLIN 和 20 次洗涤后的 WHOPES 批准的增效剂（PBO）/拟除虫菊酯之间的吸血率没有统计学差异（p＞0.05）。
结果表明，MAGNet LLIN 提供了类似于标准批准的长效蚊帐的吸血抑制、趋外性、死亡率和驱避作用，因此符合 WHOPES 的吸血标准。未经处理和 20 次洗涤的 MAGNet 与未经处理的 DuraNet 相比，对耐拟除虫菊酯的冈比亚按蚊的高吸血抑制和高个人保护率，以及 WHOPES 批准的标准拟除虫菊酯长效蚊帐，证明 MAGNet 符合 WHOPES 对长效蚊帐的第二阶段标准。
基于这项研究，MAGNet 在对高度耐药的冈比亚按蚊种群进行 20 次洗涤后，显示出对保护有很大的影响。
