Glunt Katey D, Coetzee Maureen, Huijben Silvie, Koffi A Alphonsine, Lynch Penelope A, N'Guessan Raphael, Oumbouke Welbeck A, Sternberg Eleanore D, Thomas Matthew B
Department of Entomology The Pennsylvania State University University Park PA USA.
Wits Research Institute for Malaria Faculty of Health Sciences University of the Witwatersrand Johannesburg South Africa.
Evol Appl. 2017 Dec 4;11(4):431-441. doi: 10.1111/eva.12574. eCollection 2018 Apr.
In spite of widespread insecticide resistance in vector mosquitoes throughout Africa, there is limited evidence that long-lasting insecticidal bed nets (LLINs) are failing to protect against malaria. Here, we showed that LLIN contact in the course of host-seeking resulted in higher mortality of resistant . mosquitoes than predicted from standard laboratory exposures with the same net. We also found that sublethal contact with an LLIN caused a reduction in blood feeding and subsequent host-seeking success in multiple lines of resistant mosquitoes from the laboratory and the field. Using a transmission model, we showed that when these LLIN-related lethal and sublethal effects were accrued over mosquito lifetimes, they greatly reduced the impact of resistance on malaria transmission potential under conditions of high net coverage. If coverage falls, the epidemiological impact is far more pronounced. Similarly, if the intensity of resistance intensifies, the loss of malaria control increases nonlinearly. Our findings help explain why insecticide resistance has not yet led to wide-scale failure of LLINs, but reinforce the call for alternative control tools and informed resistance management strategies.
尽管在非洲各地的媒介蚊子中广泛存在杀虫剂抗性，但证据有限，表明长效杀虫剂蚊帐（LLINs）无法预防疟疾。在这里，我们表明，在寻找宿主过程中与LLIN接触导致抗性蚊子的死亡率高于使用同一蚊帐进行标准实验室暴露所预测的死亡率。我们还发现，与LLIN的亚致死接触导致实验室和野外多株抗性蚊子的吸血量减少以及随后寻找宿主的成功率降低。使用传播模型，我们表明，当这些与LLIN相关的致死和亚致死效应在蚊子的生命周期中累积时，在蚊帐高覆盖率的情况下，它们极大地降低了抗性对疟疾传播潜力的影响。如果覆盖率下降，流行病学影响则更为明显。同样，如果抗性强度增强，疟疾控制的损失将呈非线性增加。我们的研究结果有助于解释为什么杀虫剂抗性尚未导致LLINs的大规模失效，但也强化了对替代控制工具和明智的抗性管理策略的呼吁。
