Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire.
Centre d'Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké, Côte d'Ivoire.
Malar J. 2023 Feb 1;22(1):36. doi: 10.1186/s12936-023-04455-z.
Due to the rapid expansion of pyrethroid-resistance in malaria vectors in Africa, Global Plan for Insecticide Resistance Management (GPIRM) has recommended the development of long-lasting insecticidal nets (LLINs), containing insecticide mixtures of active ingredients with different modes of action to mitigate resistance and improve LLIN efficacy. This good laboratory practice (GLP) study evaluated the efficacy of the chlorfenapyr and deltamethrin-coated PermaNet Dual, in comparison with the deltamethrin and synergist piperonyl butoxide (PBO)-treated PermaNet 3.0 and the deltamethrin-coated PermaNet 2.0, against wild free-flying pyrethroid-resistant Anopheles gambiae sensu lato (s.l.), in experimental huts in Tiassalé, Côte d'Ivoire (West Africa).
PermaNet Dual, PermaNet 3.0 and PermaNet 2.0, unwashed and washed (20 washes), were tested against free-flying pyrethroid-resistant An. gambiae s.l. in the experimental huts in Tiassalé, Côte d'Ivoire from March to August 2020. Complementary laboratory cone bioassays (daytime and 3-min exposure) and tunnel tests (nightly and 15-h exposure) were performed against pyrethroid-susceptible An. gambiae sensu stricto (s.s.) (Kisumu strain) and pyrethroid-resistant An. gambiae s.l. (Tiassalé strain).
PermaNet Dual demonstrated significantly improved efficacy, compared to PermaNet 3.0 and PermaNet 2.0, against the pyrethroid-resistant An. gambiae s.l. Indeed, the experimental hut trial data showed that the mortality and blood-feeding inhibition in the wild pyrethroid-resistant An. gambiae s.l. were overall significantly higher with PermaNet Dual compared with PermaNet 3.0 and PermaNet 2.0, for both unwashed and washed samples. The mortality with unwashed and washed samples were 93.6 ± 0.2% and 83.2 ± 0.9% for PermaNet Dual, 37.5 ± 2.9% and 14.4 ± 3.9% for PermaNet 3.0, and 7.4 ± 5.1% and 11.7 ± 3.4% for PermaNet 2.0, respectively. Moreover, unwashed and washed samples produced the respective percentage blood-feeding inhibition of 41.4 ± 6.9% and 43.7 ± 4.8% with PermaNet Dual, 51.0 ± 5.7% and 9.8 ± 3.6% with PermaNet 3.0, and 12.8 ± 4.3% and - 13.0 ± 3.6% with PermaNet 2.0. Overall, PermaNet Dual also induced higher or similar deterrence, exophily and personal protection when compared with the standard PermaNet 3.0 and PermaNet 2.0 reference nets, with both unwashed and washed net samples. In contrast to cone bioassays, tunnel tests predicted the efficacy of PermaNet Dual seen in the current experimental hut trial.
The deltamethrin-chlorfenapyr-coated PermaNet Dual induced a high efficacy and performed better than the deltamethrin-PBO PermaNet 3.0 and the deltamethrin-only PermaNet 2.0, testing both unwashed and 20 times washed samples against the pyrethroid-susceptible and resistant strains of An. gambiae s.l. The inclusion of chlorfenapyr with deltamethrin in PermaNet Dual net greatly improved protection and control of pyrethroid-resistant An. gambiae populations. PermaNet Dual thus represents a promising tool, with a high potential to reduce malaria transmission and provide community protection in areas compromised by mosquito vector resistance to pyrethroids.
由于非洲疟疾病媒对拟除虫菊酯的抗药性迅速扩大，全球杀虫剂抗药性管理计划（GPIRM）建议开发含有不同作用模式的杀虫剂混合物的长效杀虫蚊帐（LLINs），以减轻抗药性并提高 LLIN 的效果。本良好实验室规范（GLP）研究评估了氯氟醚菊酯和溴氰菊酯涂层PermaNet Dual 与溴氰菊酯和增效剂胡椒基丁醚（PBO）处理的 PermaNet 3.0 和溴氰菊酯涂层PermaNet 2.0 相比，对在科特迪瓦（西非）蒂亚萨莱的实验棚中野外飞行的抗药性拟除虫菊酯的野生按蚊 sensu lato（s.l.）的功效。
在 2020 年 3 月至 8 月期间，在科特迪瓦蒂亚萨莱的实验棚中，对未清洗和清洗（20 次）的 PermaNet Dual、PermaNet 3.0 和 PermaNet 2.0 进行了野外飞行的抗药性按蚊 s.l.的测试。还对溴氰菊酯敏感的按蚊 s.s.（基苏木品系）和溴氰菊酯抗性按蚊 s.l.（蒂亚萨莱品系）进行了补充实验室锥形生物测定（白天和 3 分钟暴露）和隧道试验（夜间和 15 小时暴露）。
PermaNet Dual 与 PermaNet 3.0 和 PermaNet 2.0 相比，对野外飞行的抗药性按蚊 s.l.的功效显著提高。事实上，野外抗药性按蚊 s.l.的死亡率和血液摄食抑制率在未清洗和清洗的样本中，PermaNet Dual 与 PermaNet 3.0 和 PermaNet 2.0 相比，总体上均显著更高。未清洗和清洗的样本中 PermaNet Dual 的死亡率分别为 93.6±0.2%和 83.2±0.9%，PermaNet 3.0 分别为 37.5±2.9%和 14.4±3.9%，PermaNet 2.0 分别为 7.4±5.1%和 11.7±3.4%。此外，未清洗和清洗的样本分别产生了 41.4±6.9%和 43.7±4.8%的按蚊 s.l.血液摄食抑制率，PermaNet Dual 为 51.0±5.7%和 9.8±3.6%，PermaNet 3.0 为 12.8±4.3%和-13.0±3.6%，PermaNet 2.0。总的来说，与标准的 PermaNet 3.0 和 PermaNet 2.0 参考网相比，PermaNet Dual 也具有更高或相似的驱避、外向性和个人保护作用，无论是未清洗还是清洗的网样本。与锥形生物测定相反，隧道试验预测了 PermaNet Dual 在当前实验棚试验中所看到的功效。
氯氟醚菊酯和溴氰菊酯涂层的 PermaNet Dual 诱导了高功效，并且比溴氰菊酯-PBO PermaNet 3.0 和仅溴氰菊酯 PermaNet 2.0 更好，对溴氰菊酯敏感和抗性的按蚊 s.l.品系的未清洗和 20 次清洗的样本进行了测试。PermaNet Dual 网中氯氟醚菊酯与溴氰菊酯的结合大大提高了对耐吡虫啉的按蚊种群的保护和控制。因此，PermaNet Dual 是一种很有前途的工具，具有降低疟疾传播和为受蚊子媒介对拟除虫菊酯抗性影响的地区提供社区保护的高潜力。
