Department of Entomology, Texas A&M University College Station, TX, USA.
Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences Ås, Norway.
Evol Appl. 2013 Dec;6(8):1171-83. doi: 10.1111/eva.12094. Epub 2013 Aug 7.
On Bioko Island, Equatorial Guinea, indoor residual spraying (IRS) has been part of the Bioko Island Malaria Control Project since early 2004. Despite success in reducing childhood infections, areas of high transmission remain on the island. We therefore examined fluctuations in the effective population size (N e ) of the malaria vector Anopheles gambiae in an area of persistent high transmission over two spray rounds. We analyzed data for 13 microsatellite loci from 791 An. gambiae specimens collected at six time points in 2009 and 2010 and reconstructed the demographic history of the population during this period using approximate Bayesian computation (ABC). Our analysis shows that IRS rounds have a large impact on N e , reducing it by 65%-92% from prespray round N e . More importantly, our analysis shows that after 3-5 months, the An. gambiae population rebounded by 2818% compared shortly following the spray round. Our study underscores the importance of adequate spray round frequency to provide continuous suppression of mosquito populations and that increased spray round frequency should substantially improve the efficacy of IRS campaigns. It also demonstrates the ability of ABC to reconstruct a detailed demographic history across only a few tens of generations in a large population.
在赤道几内亚的比奥科岛，室内残留喷洒（IRS）自 2004 年初以来一直是比奥科岛疟疾控制项目的一部分。尽管在减少儿童感染方面取得了成功，但该岛仍有一些高传播地区。因此，我们在两轮喷洒过程中检查了持续高传播地区疟疾媒介按蚊种群有效数量（Ne）的波动情况。我们分析了 2009 年和 2010 年六个时间点采集的 791 个按蚊标本的 13 个微卫星基因座的数据，并使用近似贝叶斯计算（ABC）重建了该时期种群的人口历史。我们的分析表明，IRS 轮次对 Ne 有很大的影响，将其从喷洒前的 Ne 减少了 65%-92%。更重要的是，我们的分析表明，在喷洒后 3-5 个月，与喷洒后不久相比，按蚊种群的数量反弹了 2818%。我们的研究强调了适当的喷洒轮次频率对持续抑制蚊虫种群的重要性，并且增加喷洒轮次频率将大大提高 IRS 运动的效果。它还证明了 ABC 在只有几十代的大规模种群中重建详细人口历史的能力。
