Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands.
School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi.
Malar J. 2021 May 22;20(1):232. doi: 10.1186/s12936-021-03769-0.
Current standard interventions are not universally sufficient for malaria elimination. The effects of community-based house improvement (HI) and larval source management (LSM) as supplementary interventions to the Malawi National Malaria Control Programme (NMCP) interventions were assessed in the context of an intensive community engagement programme.
The study was a two-by-two factorial, cluster-randomized controlled trial in Malawi. Village clusters were randomly assigned to four arms: a control arm; HI; LSM; and HI + LSM. Malawi NMCP interventions and community engagement were used in all arms. Household-level, cross-sectional surveys were conducted on a rolling, 2-monthly basis to measure parasitological and entomological outcomes over 3 years, beginning with one baseline year. The primary outcome was the entomological inoculation rate (EIR). Secondary outcomes included mosquito density, Plasmodium falciparum prevalence, and haemoglobin levels. All outcomes were assessed based on intention to treat, and comparisons between trial arms were conducted at both cluster and household level.
Eighteen clusters derived from 53 villages with 4558 households and 20,013 people were randomly assigned to the four trial arms. The mean nightly EIR fell from 0.010 infectious bites per person (95% CI 0.006-0.015) in the baseline year to 0.001 (0.000, 0.003) in the last year of the trial. Over the full trial period, the EIR did not differ between the four trial arms (p = 0.33). Similar results were observed for the other outcomes: mosquito density and P. falciparum prevalence decreased over 3 years of sampling, while haemoglobin levels increased; and there were minimal differences between the trial arms during the trial period.
In the context of high insecticide-treated bed net use, neither community-based HI, LSM, nor HI + LSM contributed to further reductions in malaria transmission or prevalence beyond the reductions observed over two years across all four trial arms. This was the first trial, as far as the authors are aware, to test the potential complementary impact of LSM and/or HI beyond levels achieved by standard interventions. The unexpectedly low EIR values following intervention implementation indicated a promising reduction in malaria transmission for the area, but also limited the usefulness of this outcome for measuring differences in malaria transmission among the trial arms. Trial registration PACTR, PACTR201604001501493, Registered 3 March 2016, https://pactr.samrc.ac.za/ .
目前的标准干预措施并非对所有疟疾都有效。本研究在强化社区参与项目的背景下，评估以社区为基础的房屋改善（HI）和幼虫源管理（LSM）作为马拉维国家疟疾控制规划（NMCP）干预措施的补充干预措施的效果。
这是一项在马拉维进行的两因素、集群随机对照试验。村庄集群被随机分配到四个组：对照组；HI 组；LSM 组；和 HI+LSM 组。所有组均采用马拉维 NMCP 干预措施和社区参与。在 3 年的时间里，每隔两个月进行一次家庭层面的横断面调查，以测量寄生虫学和昆虫学结果，其中包括一年的基线。主要结局指标是昆虫接种率（EIR）。次要结局指标包括蚊虫密度、恶性疟原虫流行率和血红蛋白水平。所有结局均采用意向治疗进行评估，并在集群和家庭层面进行了试验组之间的比较。
18 个来自 53 个村庄的集群共 4558 户家庭和 20013 人被随机分配到四个试验组。平均夜间 EIR 从基线年的每人 0.010 传染性叮咬（95%CI 0.006-0.015）降至试验最后一年的 0.001（0.000，0.003）。在整个试验期间，四组之间的 EIR 没有差异（p=0.33）。其他结果也观察到类似的结果：在 3 年的采样期间，蚊虫密度和恶性疟原虫流行率下降，而血红蛋白水平上升；试验期间，各组之间的差异很小。
在高使用经杀虫剂处理的蚊帐的情况下，基于社区的 HI、LSM 或 HI+LSM 均未对疟疾传播或流行率的进一步降低做出贡献，这低于所有四组在两年内观察到的降低幅度。据作者所知，这是首次在标准干预措施水平之外测试 LSM 和/或 HI 的潜在补充影响的试验。干预实施后意外的低 EIR 值表明该地区疟疾传播有令人鼓舞的减少，但也限制了该结果用于测量试验组之间疟疾传播差异的有用性。
试验注册 PACTR，PACTR201604001501493，注册日期 2016 年 3 月 3 日，https://pactr.samrc.ac.za/ 。
