Imperial College London, Life Sciences Division, Silwood Park, Ascot, England and Present address: Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Scotland
Institute of Biology, Université de Neuchâtel, 11 rue Emile-Argand, CH-2000 Neuchâtel, Switzerland.
Evol Med Public Health. 2015 Aug 29;2015(1):205-15. doi: 10.1093/emph/eov019.
The evolution of insecticide-resistance in malaria vectors is emerging as a serious challenge for the control of malaria. Modelling the spread of insecticide-resistance is an essential tool to understand the evolutionary pressures and dynamics caused by the application of insecticides.
We developed a population-genetic model of the spread of insecticide-resistance in a population of Anopheles vectors in response to insecticides used either as adulticides (focussing on insecticide-treated bed nets (ITNs)) or as larvicides (either for the control of malaria or, as an inadvertent side-product, in agriculture).
We show that indoor use of insecticides leads to considerably less selection pressure than their use as larvicides, supporting the idea that most resistance of malaria vectors is due to the agricultural use of the insecticides that are also used for malaria control. The reasons for the relatively low selection pressure posed by adulticides are (i) that males are not affected by the ITNs and, in particular, (ii) that the insecticides are also repellents, keeping mosquitoes at bay from contacting the insecticide but also driving them to bite either people who do not use the insecticide or alternative hosts.
We conclude by discussing the opposing public health benefits of high repellency at an epidemiological and an evolutionary timescale: whereas repellency is beneficial to delay the evolution of resistance, other models have shown that it decreases the population-level protection of the insecticide.
昆虫抗药性的演变正成为疟疾控制的严重挑战。模拟抗药性的传播是了解杀虫剂应用引起的进化压力和动态的重要工具。
我们开发了一种在疟疾传播媒介按蚊种群中抗药性传播的群体遗传学模型，以应对作为成虫杀虫剂（主要针对经杀虫剂处理的蚊帐（ITN））或幼虫杀虫剂（无论是控制疟疾还是作为农业的意外副作用）使用的杀虫剂。
我们表明，室内使用杀虫剂比作为幼虫杀虫剂的使用产生的选择压力小得多，这支持了这样一种观点，即疟疾媒介的大多数抗药性是由于农业使用了也用于疟疾控制的杀虫剂。成虫杀虫剂的选择压力相对较低的原因是（i）雄性不受 ITN 的影响，特别是（ii）杀虫剂也是驱避剂，使蚊子远离接触杀虫剂，但也驱使它们叮咬不使用杀虫剂的人或替代宿主。
我们通过在流行病学和进化时间尺度上讨论高驱避性的相反公共卫生效益来得出结论：虽然驱避性有利于延迟抗药性的进化，但其他模型表明，它降低了杀虫剂对种群水平的保护。
