Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique.
ISGlobal, Barcelona, Spain.
PLoS One. 2022 Oct 3;17(10):e0272655. doi: 10.1371/journal.pone.0272655. eCollection 2022.
Indoor residual spraying (IRS) has been and remains an important malaria control intervention in southern Mozambique, South Africa and Eswatini. A better understanding of the effectiveness of IRS campaigns is critical to guide future elimination efforts. We analyze the three IRS campaigns conducted during a malaria elimination demonstration project in southern Mozambique, the "Magude project", and propose a new method to calculate the efficacy of IRS campaigns adjusting for IRS coverage, pace of house spraying and IRS residual efficacy on different wall types. Anopheles funestus sensu lato (s.l.) and An. gambiae s.l. were susceptible to pirimiphos-methyl and DDT. Anopheles funestus s.l. was resistant to pyrethroids, with 24h post-exposure mortality being lower for An. funestus sensu stricto (s.s.) than for An. parensis (collected indoors). The percentage of structures sprayed was above 90% and percentage of people covered above 86% in all three IRS campaigns. The percentage of households sprayed was above 83% in 2015 and 2016, but not assessed in 2017. Mosquito mortality 24h post-exposure stayed above 80% for 196 days after the 2016 IRS campaign and 222 days after the 2017 campaign and was 1.5 months longer on mud walls than on cement walls. This was extended by up to two months when 120h post-exposure mortality was considered. The district-level realized IRS efficacy was 113 days after the 2016 campaign. While the coverage of IRS campaigns in Magude were high, IRS protection did not remain optimal for the entire high malaria transmissions season. The use of a longer-lasting IRS product could have further supported the interruption of malaria transmission in the district. To better estimate the protection afforded by IRS campaigns, National Malaria Control Programs and partners are encouraged to adjust the calculation of IRS efficacy for IRS coverage, pace of house spraying during the campaign and IRS efficacy on different wall types combined with wall type distribution in the sprayed area.
室内滞留喷洒（IRS）一直是并仍然是南非和斯威士兰南部重要的疟疾控制干预措施。更好地了解 IRS 运动的效果对于指导未来的消除工作至关重要。我们分析了在莫桑比克南部进行的疟疾消除示范项目“马古德项目”期间进行的三次 IRS 运动，并提出了一种新方法来计算 IRS 运动的效果，方法是调整 IRS 覆盖率、房屋喷洒速度和不同墙壁类型上 IRS 的残留效果。按蚊属（Anopheles）长角亚属（s.l.）和冈比亚按蚊亚属（s.l.）对派卡瑞丁和滴滴涕敏感。按蚊属长角亚属（s.l.）对拟除虫菊酯有抗药性，24 小时接触后死亡率按蚊属（s.s.）比按蚊属（室内采集）低。所有三次 IRS 运动的喷洒结构比例均超过 90%，覆盖人群比例均超过 86%。2015 年和 2016 年，喷洒的家庭比例均超过 83%，但 2017 年未进行评估。2016 年 IRS 运动后 24 小时内蚊虫死亡率保持在 80%以上，2017 年 IRS 运动后 222 天内保持在 80%以上，泥墙比水泥墙高 1.5 个月。考虑到 120 小时接触后死亡率，这一数字延长了两个月。2016 年 IRS 运动后第 113 天，实现了区县级 IRS 效果。尽管 Magude 的 IRS 运动覆盖率很高，但 IRS 保护并没有在整个高疟疾传播季节保持最佳状态。使用更持久的 IRS 产品可以进一步支持该地区中断疟疾传播。为了更好地估计 IRS 运动提供的保护，鼓励国家疟疾控制规划和合作伙伴调整 IRS 效果的计算，方法是调整 IRS 覆盖率、运动期间房屋喷洒速度以及不同墙壁类型上 IRS 的效果，同时结合喷洒区域的墙壁类型分布。
