West African International Center for Excellence in Malaria Research/Malaria Research and Training Center/International Center for Excellence in Research/University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali.
Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, Florida.
Am J Trop Med Hyg. 2023 Aug 7;109(3):616-620. doi: 10.4269/ajtmh.22-0808. Print 2023 Sep 6.
In Mali, malaria vector control relies mostly on long-lasting insecticidal nets and indoor residual spraying (IRS). From 2008 to 2016, an IRS program was implemented in the district of Koulikoro. After a significant reduction in malaria indicators, IRS was stopped in 2016. This study evaluated the effect of IRS withdrawal on entomological parameters of malaria transmission and incidence in children aged 6 months to 10 years in the district of Koulikoro. Entomological parameters of malaria transmission during the last year of IRS implementation in 2016 were compared with those obtained 2 years after IRS withdrawal in 2018 in two villages of Koulikoro. Mosquito vectors were collected by mouth aspiration and pyrethrum spray catches in the villages to monitor these transmission parameters. A sharp increase (10.8 times higher) in vector abundance after IRS withdrawal was observed. The infection rate of Anopheles gambiae sensu lato to Plasmodium falciparum increased from zero during IRS implementation to 14.8% after IRS withdrawal. The average entomological inoculation rate, which was undetectable before, was 1.22 infected bites per person per month 2 years after IRS was withdrawn, and the cumulative malaria incidence rate observed after IRS was 4.12 times (15.2% versus 3.7%) higher than that observed in 2016 in the villages before IRS withdrawal. This study showed a resurgence of malaria transmission and incidence in the Koulikoro health district after IRS was withdrawn. Thus, to manage the potential consequences of malaria transmission resurgence, alternative approaches are needed when stopping successful malaria control interventions.
在马里，疟疾病媒控制主要依赖长效杀虫蚊帐和室内滞留喷洒（IRS）。从 2008 年到 2016 年，在库利科罗地区实施了 IRS 项目。在疟疾指标显著下降后，IRS 于 2016 年停止。本研究评估了 IRS 停止对库利科罗区 6 个月至 10 岁儿童疟疾传播和发病率的昆虫学参数的影响。在 2016 年 IRS 实施的最后一年，对 IRS 停止后 2018 年两个村庄的疟疾传播昆虫学参数进行了比较。通过口吸和拟除虫菊酯喷雾收集蚊子病媒，以监测这些传播参数。在 IRS 停止后，观察到媒介丰度急剧增加（增加了 10.8 倍）。对恶性疟原虫的冈比亚按蚊亚种的感染率从 IRS 实施期间的零增加到 IRS 停止后的 14.8%。在 IRS 停止后 2 年，平均昆虫接种率从之前未检测到的水平上升到每人每月 1.22 人感染的蚊虫叮咬，IRS 停止后的累积疟疾发病率比 IRS 停止前 2016 年的村庄高 4.12 倍（15.2%比 3.7%）。本研究表明，在 IRS 停止后，库利科罗卫生区的疟疾传播和发病率再次出现。因此，在停止成功的疟疾控制干预措施时，需要采取替代方法来管理疟疾传播再次出现的潜在后果。
