Epidemiology Unit, Ministry of Health, Colombo, Sri Lanka.
National Dengue Control Unit (NDCU), Ministry of Health, Colombo, Sri Lanka.
Trials. 2023 Jan 4;24(1):9. doi: 10.1186/s13063-022-06998-z.
Spatial repellents (SRs) have been widely used for prevention of mosquito bites, but their efficacy in reducing Aedes-borne viruses (ABV) has not been tested rigorously at large scale in Asia. To address this knowledge gap, a trial to evaluate the efficacy of Mosquito Shield™, a transfluthrin SR, was developed in Gampaha District of Sri Lanka across three Medical Officer of Health areas; i.e., Negombo, Wattala, and Kelaniya.
This trial is a cluster-randomized, placebo-controlled, double-blinded clinical trial. A total of ~14,430 subjects aged ≥ 6 months in 30 clusters (15 intervention, 15 placebo) from ~3900 households (HH) will be randomly selected for enrolment into a "febrile surveillance cohort." A subset of the surveillance cohort, ~3570 subjects aged ≥4-16 years that test seronegative (naïve) or are serologically positive for a previous single dengue virus (DENV) infection (monotypic) at baseline sampling, will be enrolled into a "longitudinal cohort" for measuring DENV infection based on laboratory-confirmed seroconversion during the trial. Persons identified positive for antibodies against multiple DENV serotypes (multitypic) at baseline will be monitored for secondary analyses. Active ABV disease will be assessed using an enhanced passive surveillance system with case ascertainment performed in designated healthcare facilities. Serum samples will be taken from longitudinal cohort subjects within 1-2 weeks of when intervention is first deployed (T0) with additional samples taken ~12 (T1) and ~24 months (T2) from baseline sampling. DENV seroconversion and ABV active disease rates from baseline (pre-intervention) and follow-up (post-intervention) samples will be compared between intervention and placebo clusters. Participating houses will be monitored entomologically (indoor adult Aedes aegypti population densities and adult female blood fed status) within 3 months before intervention deployment and monthly during the intervention phase. Entomological surveys will monitor indoor adult Ae. aegypti population densities and blood fed status. Dengue incidence in each cohort will be estimated and compared to determine the public health benefit of using an SR. Entomological parameters will be measured to determine if there are entomological correlates of SR efficacy that may be useful for the evaluation of new SR products.
The trial will serve as an efficacy assessment of SR products in South Asia. Results will be submitted to the World Health Organization Vector Control Advisory Group for assessment of public health value towards an endorsement to recommend inclusion of SRs in ABV control programs.
Sri Lanka Clinical Trial Registry SLCTR /2022/018. Registered on July 1, 2022.
gov NCT05452447 . Registered on July 11, 2022. The Universal Trial Number is U1111-1275-3055.
空间驱避剂（SRs）已被广泛用于预防蚊虫叮咬，但它们在亚洲大规模减少登革热病毒（ABV）方面的功效尚未经过严格测试。为了解决这一知识空白，在斯里兰卡的加勒地区开展了一项评估 Mosquito Shield™（一种四氟苯菊酯 SR）功效的试验，该试验涉及三个卫生官员辖区；即尼甘布、瓦塔拉和凯莱尼亚。
该试验是一项整群随机、安慰剂对照、双盲临床试验。将从约 3900 户家庭（HH）中随机选择约 14430 名年龄≥6 个月的个体（15 名干预组，15 名安慰剂组）进入“发热监测队列”。监测队列的一个子集，即约 3570 名年龄≥4-16 岁的个体，在基线采样时血清学阴性（初免）或先前单次登革热病毒（DENV）感染（单型）呈血清学阳性（单型），将被纳入“纵向队列”，以根据试验期间实验室确认的血清转化来测量 DENV 感染。在基线时检测出针对多种 DENV 血清型（多型）抗体的个体将进行二次分析。通过在指定医疗机构进行病例确定的强化被动监测系统评估活性 ABV 疾病。将在干预首次部署后 1-2 周内（T0）从纵向队列受试者中采集血清样本，并在基线采样后约 12（T1）和 24 个月（T2）时采集额外样本。将比较干预和安慰剂组之间从基线（干预前）和随访（干预后）样本得出的 DENV 血清转化率和 ABV 活动性疾病率。在干预部署前 3 个月内以及干预期间每月，对参与房屋进行蚊虫学监测（室内成蚊埃及伊蚊种群密度和成年雌性吸血状态）。蚊虫调查将监测室内成蚊埃及伊蚊种群密度和吸血状态。将估算每个队列的登革热发病率，并进行比较，以确定使用 SR 的公共卫生效益。将测量蚊虫学参数，以确定是否存在可能有助于评估新的 SR 产品的 SR 功效的蚊虫学相关性。
该试验将作为南亚对 SR 产品的功效评估。结果将提交给世界卫生组织病媒控制咨询小组，以评估其对推荐将 SR 纳入 ABV 控制计划的公共卫生价值。
斯里兰卡临床试验注册处 SLCTR /2022/018。于 2022 年 7 月 1 日注册。
gov NCT05452447。于 2022 年 7 月 11 日注册。通用试验编号为 U1111-1275-3055。
