Here, we report the first population genetic study to examine the impact of indoor residual spraying (IRS) on Plasmodium falciparum in humans. This study was conducted in an area of high seasonal malaria transmission in Bongo District, Ghana. IRS was implemented during the dry season (November–May) in three consecutive years between 2013 and 2015 to reduce transmission and attempt to bottleneck the parasite population in humans towards lower diversity with greater linkage disequilibrium. The study was done against a background of widespread use of long-lasting insecticidal nets, typical for contemporary malaria control in West Africa. Microsatellite genotyping with 10 loci was used to construct 392 P. falciparum multilocus infection haplotypes collected from two age-stratified cross-sectional surveys at the end of the wet seasons pre- and post-IRS. Three-rounds of IRS, under operational conditions, led to a >90% reduction in transmission intensity and a 35.7% reduction in the P. falciparum prevalence (p < .001). Despite these declines, population genetic analysis of the infection haplotypes revealed no dramatic changes with only a slight, but significant increase in genetic diversity (H_e: pre-IRS = 0.79 vs. post-IRS = 0.81, p = .048). Reduced relatedness of the parasite population (p < .001) was observed post-IRS, probably due to decreased opportunities for outcrossing. Spatiotemporal genetic differentiation between the pre- and post-IRS surveys (D = 0.0329 [95% CI: 0.0209 – 0.0473], p = .034) was identified. These data provide a genetic explanation for the resilience of P. falciparum to short-term IRS programmes in high-transmission settings in sub-Saharan Africa.

中文翻译：

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西非加纳季节性疟疾高传播地区室内滞留喷洒对恶性疟原虫微卫星变异的影响


在此，我们报告了第一项群体遗传学研究，旨在检验室内滞留喷洒（IRS）对人类恶性疟原虫的影响。这项研究是在加纳邦戈区季节性疟疾传播高发地区进行的。 IRS 在 2013 年至 2015 年连续三年在旱季（11 月至 5 月）实施，以减少传播并试图限制人类寄生虫种群，使其多样性降低、连锁不平衡加剧。这项研究是在广泛使用长效杀虫蚊帐的背景下进行的，这是西非当代疟疾控制的典型做法。使用10个位点的微卫星基因分型构建392 P 。恶性疟原虫多位点感染单倍型是从 IRS 前后雨季结束时的两次年龄分层横断面调查中收集的。在运行条件下，三轮 IRS 导致传输强度降低 90% 以上， P降低 35.7%。恶性疟原虫患病率 ( p < .001)。尽管出现这些下降，但感染单倍型的群体遗传分析显示，没有发生显着变化，遗传多样性仅有轻微但显着的增加（ He _： IRS 前 = 0.79 对比 IRS 后 = 0.81， p = .048）。 IRS 后观察到寄生虫种群的相关性降低 ( p < .001)，这可能是由于异型杂交机会减少。确定了 IRS 调查前后的时空遗传差异 ( D = 0.0329 [95% CI: 0.0209 – 0.0473], p = .034)。这些数据为P.的恢复力提供了遗传解释。恶性疟原虫到撒哈拉以南非洲高传播地区的短期 IRS 计划。