Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 2320, New Orleans, 70112, USA.
PATH Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Chainama Hospital College Grounds, Lusaka, Zambia.
Malar J. 2021 Apr 1;20(1):173. doi: 10.1186/s12936-021-03710-5.
Widespread insecticide resistance to pyrethroids could thwart progress towards elimination. Recently, the World Health Organization has encouraged the use of non-pyrethroid insecticides to reduce the spread of insecticide resistance. An electronic tool for implementing and tracking coverage of IRS campaigns has recently been tested (mSpray), using satellite imagery to improve the accuracy and efficiency of the enumeration process. The purpose of this paper is to retrospectively analyse cross-sectional observational data to provide evidence of the epidemiological effectiveness of having introduced Actellic 300CS and the mSpray platform into IRS programmes across Zambia.
Health facility catchment areas in 40 high burden districts in 5 selected provinces were initially targeted for spraying. The mSpray platform was used in 7 districts in Luapula Province. An observational study design was used to assess the relationship between IRS exposure and confirmed malaria case incidence. A random effects Poisson model was used to quantify the effect of IRS (with and without use of the mSpray platform) on confirmed malaria case incidence over the period 2013-2017; analysis was restricted to the 4 provinces where IRS was conducted in each year 2014-2016.
IRS was conducted in 283 health facility catchment areas from 2014 to 2016; 198 health facilities from the same provinces, that received no IRS during this period, served as a comparison. IRS appears to be associated with reduced confirmed malaria incidence; the incidence rate ratio (IRR) was lower in areas with IRS but without mSpray, compared to areas with no IRS (IRR = 0.91, 95% CI 0.84-0.98). Receiving IRS with mSpray significantly lowered confirmed case incidence (IRR = 0.75, 95% CI 0.66-0.86) compared to no IRS. IRS with mSpray resulted in lower incidence compared to IRS without mSpray (IRR = 0.83, 95% CI 0.72-0.95).
IRS using Actellic-CS appears to substantially reduce malaria incidence in Zambia. The use of the mSpray tool appears to improve the effectiveness of the IRS programme, possibly through improved population level coverage. The results of this study lend credence to the anecdotal evidence of the effectiveness of 3GIRS using Actellic, and the importance of exploring new platforms for improving effective population coverage of areas targeted for spraying.
广泛的杀虫剂对拟除虫菊酯的抗药性可能会阻碍消除工作的进展。最近，世界卫生组织鼓励使用非拟除虫菊酯杀虫剂来减少杀虫剂抗药性的传播。一种用于实施和跟踪 IRS 运动覆盖率的电子工具（mSpray）最近已经过测试，它利用卫星图像来提高计数过程的准确性和效率。本文的目的是回顾性分析横断面观察数据，为在赞比亚 IRS 项目中引入 Actellic 300CS 和 mSpray 平台提供流行病学效果的证据。
最初选择了 5 个选定省份的 40 个高负担地区的卫生机构集水区进行喷洒。卢阿普拉省的 7 个地区使用了 mSpray 平台。采用观察性研究设计来评估 IRS 暴露与确诊疟疾病例发生率之间的关系。使用随机效应泊松模型来量化 IRS（使用和不使用 mSpray 平台）对 2013-2017 年确诊疟疾病例发生率的影响；分析仅限于 2014-2016 年每年在 IRS 进行的 4 个省份。
2014 年至 2016 年在 283 个卫生机构集水区进行了 IRS；来自同一省份的 198 个卫生机构在这期间没有接受 IRS，作为对照。IRS 似乎与降低确诊疟疾发病率有关；与没有 IRS 的地区相比，接受 IRS 但没有使用 mSpray 的地区发病率较低（发病率比[IRR]为 0.91，95%CI 0.84-0.98）。与没有 IRS 的地区相比，接受 IRS 并使用 mSpray 显著降低了确诊病例的发病率（IRR 为 0.75，95%CI 0.66-0.86）。与没有使用 mSpray 的 IRS 相比，使用 mSpray 的 IRS 导致发病率较低（IRR 为 0.83，95%CI 0.72-0.95）。
在赞比亚，使用 Actellic-CS 的 IRS 似乎可大大降低疟疾发病率。使用 mSpray 工具似乎可通过提高人群水平的覆盖率来提高 IRS 计划的效果。本研究结果证实了使用 Actellic 进行 3GIRS 的传闻证据的有效性，以及探索新平台以提高喷洒目标地区有效人口覆盖率的重要性。
