在莫桑比克高度流行地区，室内残留喷洒对疟疾发病率的持续影响：一项基于群组随机研究的结果。

Incremental impact on malaria incidence following indoor residual spraying in a highly endemic area with high standard ITN access in Mozambique: results from a cluster-randomized study.

机构信息

ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.

Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique.

出版信息

Malar J. 2021 Feb 10;20(1):84. doi: 10.1186/s12936-021-03611-7.

BACKGROUND

Attaining the goal of reducing the global malaria burden is threatened by recent setbacks in maintaining the effectiveness of vector control interventions partly due to the emergence of pyrethroid resistant vectors. One potential strategy to address these setbacks could be combining indoor residual spraying (IRS) with non-pyrethroids and standard insecticide-treated nets (ITNs). This study aimed to provide evidence on the incremental epidemiological benefit of using third-generation IRS product in a highly endemic area with high ITN ownership.

METHODS

A cluster-randomized, open-label, parallel-arms, superiority trial was conducted in the Mopeia district in Zambezia, Mozambique from 2016 to 2018. The district had received mass distribution of alphacypermethrin ITNs two years before the trial and again mid-way. 86 clusters were defined, stratified and randomized to receive or not receive IRS with pirimiphos-methyl (Actellic®300 CS). Efficacy of adding IRS was assessed through malaria incidence in a cohort of children under five followed prospectively for two years, enhanced passive surveillance at health facilities and by community health workers, and yearly cross-sectional surveys at the peak of the transmission season.

FINDINGS

A total of 1536 children were enrolled in the cohort. Children in the IRS arm experienced 4,801 cases (incidence rate of 3,532 per 10,000 children-month at risk) versus 5,758 cases in the no-IRS arm (incidence rate of 4,297 per 10,000 children-month at risk), resulting in a crude risk reduction of 18% and an incidence risk ratio of 0.82 (95% CI 0.79-0.86, p-value < 0.001). Facility and community passive surveillance showed a malaria incidence of 278 per 10,000 person-month in the IRS group (43,974 cases over 22 months) versus 358 (95% CI 355-360) per 10,000 person-month at risk in the no-IRS group (58,030 cases over 22 months), resulting in an incidence rate ratio of 0.65 (95% CI 0.60-0.71, p < 0.001). In the 2018 survey, prevalence in children under five in the IRS arm was significantly lower than in the no-IRS arm (OR 0.54, 95% CI, 0.31-0.92, p = 0.0241).

CONCLUSION

In a highly endemic area with high ITN access and emerging pyrethroid resistance, adding IRS with pirimiphos-methyl resulted in significant additional protection for children under five years of age.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02910934, registered 22 September 2016, https://clinicaltrials.gov/ct2/show/NCT02910934?term=NCT02910934&draw=2&rank=1 .

背景

由于拟除虫菊酯抗性媒介的出现，部分破坏了病媒控制干预措施的有效性，降低全球疟疾负担的目标受到了最近的挫折。应对这些挫折的一种潜在策略可能是将室内滞留喷洒（IRS）与非拟除虫菊酯和标准驱虫蚊帐（ITN）结合使用。本研究旨在为在高度流行地区和高 ITN 拥有率地区使用第三代 IRS 产品提供额外的流行病学效益证据。

方法

2016 年至 2018 年，在莫桑比克赞比西亚省的莫佩亚区进行了一项集群随机、开放标签、平行臂、优效性试验。该地区在试验前两年和中途两次接受了大规模发放的溴氰菊酯 ITN。将 86 个集群定义、分层和随机分组，接受或不接受使用吡丙醚（Actellic®300 CS）的 IRS。通过对两年内前瞻性随访的 5 岁以下儿童的疟疾发病率、在卫生设施和社区卫生工作者处加强的被动监测以及在传播季节高峰进行的年度横断面调查，评估添加 IRS 的效果。

结果

共有 1536 名儿童入组该队列。IRS 组的儿童发生了 4801 例病例（发病率为每 10000 名儿童-月 3532 例），而无 IRS 组发生了 5758 例病例（发病率为每 10000 名儿童-月 4297 例），导致发病率降低了 18%，发病率风险比为 0.82（95%CI 0.79-0.86，p 值<0.001）。设施和社区的被动监测显示，IRS 组的疟疾发病率为每 10000 人-月 278 例（22 个月共 43974 例），而无 IRS 组的发病率为每 10000 人-月 358 例（95%CI 355-360）（22 个月共 58030 例），导致发病率风险比为 0.65（95%CI 0.60-0.71，p<0.001）。在 2018 年的调查中，IRS 组 5 岁以下儿童的患病率明显低于无 IRS 组（OR 0.54，95%CI，0.31-0.92，p=0.0241）。