PMI VectorLink Project, PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA, 98121, USA.
Programme National de Lutte Contre le Paludisme, Ouagadougou, Burkina Faso.
Malar J. 2024 Aug 2;23(1):229. doi: 10.1186/s12936-024-05054-2.
Indoor residual spraying (IRS) is a cornerstone malaria control intervention in Burkina Faso. From 2018 to 2021, non-pyrethroid IRS was implemented annually in two regions of Burkina Faso with distinct malaria transmission patterns, concurrently with annual seasonal malaria chemoprevention (SMC), and a mass insecticide-treated net (ITN) distribution in 2019.
A retrospective quasi-experimental approach was used to evaluate the impact of the 2018, 2020, and 2021 IRS campaigns on routinely reported confirmed malaria case incidence at health facilities. The 2019 campaign was excluded due to lack of data reporting during a health sector strike. Controlled interrupted time series models were fit to detect changes in level and trend in malaria case incidence rates following each IRS campaign when compared to the baseline period 24-months before IRS. IRS districts Solenzo (Sudano-Sahelien climate), and Kampti (tropical climate) were compared with neighbouring control districts and the analyses were stratified by region. Modelled health facility catchment population estimates based on travel time to health facilities and weighted by non-malaria outpatient visits were used as an offset. The study period encompassed July 2016 through June 2022, excluding July 2018 to June 2019.
District-level population and structure coverage achieved by IRS campaigns was greater than 85% in 2018, 2020, and 2021 in Solenzo and Kampti. In Solenzo a significant difference in malaria case incidence rates was detected after the 2018 campaign (IRR = 0.683; 95% CI 0.564-0.827) when compared to the control district. The effect was not detected following the 2020 or 2021 IRS campaigns. In Kampti, estimated malaria incidence rates were between 36 and 38% lower than in the control district following all three IRS campaigns compared to the baseline period.
Implementation of IRS in Kampti, a tropical region of Burkina Faso, appeared to have a consistent significant beneficial impact on malaria case rates. An initial positive impact in Solenzo after the first IRS campaign was not sustained in the successive evaluated IRS campaigns. This study points to a differential effect of IRS in different malaria transmission settings and in combination with ITN and SMC implementation.
室内滞留喷洒（IRS）是布基纳法索控制疟疾的一项重要干预措施。从 2018 年到 2021 年，布基纳法索两个地区每年都实施非拟除虫菊酯 IRS，这两个地区的疟疾传播模式不同，同时每年进行季节性疟疾化学预防（SMC），并在 2019 年大规模分发驱虫蚊帐。
采用回顾性准实验方法，评估 2018 年、2020 年和 2021 年 IRS 运动对医疗机构常规报告的确诊疟疾病例发病率的影响。由于在卫生部门罢工期间缺乏数据报告，2019 年的运动被排除在外。在 IRS 之前的 24 个月的基线期之后，当与基线期相比时，每个 IRS 运动后，控制中断时间序列模型都被用来检测疟疾病例发病率的水平和趋势的变化。对 Solenzo（萨赫勒地区）和 Kampti（热带地区）的 IRS 区与邻近对照区进行比较，并按地区进行分层分析。根据到医疗机构的旅行时间和非疟疾门诊就诊次数加权的模型估计的医疗机构集水区人口估计数被用作偏移量。研究期间为 2016 年 7 月至 2022 年 6 月，不包括 2018 年 7 月至 2019 年 6 月。
2018 年、2020 年和 2021 年，Solenzo 和 Kampti 的 IRS 运动的地区级人口和结构覆盖率均超过 85%。在 Solenzo，与对照区相比，2018 年 IRS 运动后疟疾发病率有显著差异（IRR=0.683；95%CI 0.564-0.827）。2020 年或 2021 年 IRS 运动后未检测到这种效果。在 Kampti，与基线期相比，在所有三次 IRS 运动后，估计的疟疾发病率比对照区低 36%至 38%。
在布基纳法索热带地区 Kampti 实施 IRS 似乎对疟疾发病率有持续的显著积极影响。在第一次 IRS 运动后，Solenzo 最初的积极影响在随后评估的 IRS 运动中并未持续。本研究表明 IRS 在不同的疟疾传播环境中以及与 ITN 和 SMC 实施相结合时具有不同的效果。
