Department of Zoological Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Public Health Entomology Research Team, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
BMC Med. 2024 Jan 29;22(1):41. doi: 10.1186/s12916-024-03255-9.
Conventional vector control strategies have significantly reduced the malaria burden. The sustainability of these methods is currently challenged. Odour-based traps are emerging technologies that can complement the existing tools. Implementation of odour-based traps for mass trapping is limited due to the restricted range of vectors caught with available carbon dioxide-dependent lures, and the lack of comprehensive field studies. The objective of this study was to assess the impact of odour-mediated mass trapping targeting outdoor vectors, using a synthetic cattle urine lure that attracts a wide range of vector species in a variety of physiological states, on malaria prevalence and entomological parameters to determine malaria transmission intensities.
A controlled before-and-after study was conducted in two rural communities in southern Ethiopia. Baseline monthly entomological and seasonal cross-sectional malaria prevalence surveys were conducted in both communities for a year. Then, mass trapping of mosquitoes was conducted in one of the villages, while the monthly entomological surveillance and seasonal malaria prevalence surveys continued in both villages. Generalised linear mixed models were constructed and tested to determine which factors were significantly affected by the intervention.
Mass trapping contributed to the reduction of the population of the principal malaria vector, Anopheles arabiensis, and the associated entomological indicators, the human bite rate (HBR) and the entomological inoculation rate (EIR), in the intervention village compared to the control village. The intervention village had an average HBR by An. arabiensis of 3.0 (95% CI 1.4-4.6) during the peak malaria transmission season, compared to 10.5 (95% CI - 0.5-21.5; P < 0.0001) in the control village. The intervention village (mean 0.02, 95% CI - 0.05-0.4.8) had a daily EIR eight times lower than the control village (mean 0.17, 95% CI), which likely contributed to the reduced malaria prevalence in the intervention community following its introduction by ca. 60% (95% CI 55-63).
The combined use of odour-based mass trapping and conventional control strategies coincided with a reduction of human-vector contact and malaria prevalence, providing support for odour-baited technologies as a viable option for next-generation vector control tools. Further cluster-randomised control studies are recommended in different eco-epidemiological settings with varying malaria transmission intensities.
传统的病媒控制策略已显著降低了疟疾负担。这些方法的可持续性目前受到挑战。基于气味的诱捕器是新兴技术，可以补充现有工具。由于现有的二氧化碳依赖型诱饵只能捕获有限范围的媒介，而且缺乏全面的现场研究，因此基于气味的诱捕器的大规模诱捕实施受到限制。本研究的目的是评估使用一种合成牛尿诱饵针对户外媒介进行气味介导的大规模诱捕的效果，该诱饵可以吸引多种不同生理状态的媒介物种，以确定疟疾流行率和昆虫学参数，从而确定疟疾传播强度。
在埃塞俄比亚南部的两个农村社区进行了一项对照前后研究。在这两个社区进行了为期一年的基线每月昆虫学和季节性横断面疟疾流行率调查。然后，在一个村庄进行了大规模诱捕蚊子，而在两个村庄继续进行每月昆虫学监测和季节性疟疾流行率调查。构建并测试了广义线性混合模型，以确定哪些因素受到干预的显著影响。
与对照村相比，大规模诱捕有助于减少主要疟疾媒介按蚊的数量以及相关的昆虫学指标，如人咬率（HBR）和昆虫接种率（EIR）。干预村在疟疾传播高峰期的平均 HBR 为 3.0（95%置信区间 1.4-4.6），而对照村为 10.5（95%置信区间-0.5-21.5；P<0.0001）。干预村（平均 0.02，95%置信区间-0.05-0.4）的每日 EIR 比对照村（平均 0.17，95%置信区间）低 8 倍，这可能导致干预社区在引入后疟疾流行率降低了约 60%（95%置信区间 55-63）。
基于气味的大规模诱捕与传统控制策略相结合，减少了人与媒介的接触，降低了疟疾的流行率，为气味诱饵技术作为下一代病媒控制工具的可行选择提供了支持。建议在不同的生态流行病学环境中，根据疟疾传播强度的不同，开展进一步的集群随机对照研究。
