BACKGROUND The complexity of mosquito-borne diseases poses a major challenge to global health efforts to mitigate their impact on people residing in sub-tropical and tropical regions, to travellers and deployed military personnel. To supplement drug- and vaccine-based disease control programmes, other strategies are urgently needed, including the direct control of disease vectors. Modern vector control research generally focuses on identifying novel active ingredients and/or innovative methods to reduce human-mosquito interactions. These efforts include the evaluation of spatial repellents, which are compounds capable of altering mosquito feeding behaviour without direct contact with the chemical source. METHODS This project examined the impact of airborne transfluthrin from impregnated textile materials on two important malaria vectors, Anopheles dirus and Anopheles minimus. Repellency was measured by movement within taxis cages within a semi-field environment at the National Institute of Hygiene and Epidemiology in Hanoi, Vietnam. Knockdown and mortality were measured in adult mosquito bioassay cages. Metered-volume air samples were collected at a sub-set of points in the mosquito exposure trial. RESULTS Significant differences in knockdown/mortality were observed along a gradient from the exposure source with higher rates of knockdown/mortality at 2 m and 4 m when compared with the furthest distance (16 m). Knockdown/mortality was also greater at floor level and 1.5 m when compared to 3 m above the floor. Repellency was not significantly different except when comparing 2 m and 16 m taxis cages. Importantly, the two species reacted differently to transfluthrin, with An. minimus being more susceptible to knockdown and mortality. The measured concentrations of airborne transfluthrin ranged from below the limit of detection to 1.32 ng/L, however there were a limited number of evaluable samples complicating interpretation of these results. CONCLUSIONS This study, measuring repellency, knockdown and mortality in two malaria vectors in Vietnam demonstrates that both species are sensitive to airborne transfluthrin. The differences in magnitude of response between the two species requires further study before use in large-scale vector control programmes to delineate how spatial repellency would impact the development of insecticide resistance and the disruption of biting behaviour.

中文翻译：

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跨氟菊酯对越南主要疟疾蚊子媒介的空间驱避性的影响：按蚊和小按蚊。

背景技术蚊媒疾病的复杂性对减轻其对居住在亚热带和热带地区的人们，旅行者和部署的军事人员的影响的全球卫生工作提出了重大挑战。为了补充基于药物和疫苗的疾病控制计划，迫切需要其他策略，包括直接控制病媒。现代媒介控制研究通常集中于确定新型活性成分和/或减少人-蚊相互作用的创新方法。这些努力包括对空间驱虫剂的评估，这些驱虫剂是能够改变蚊子摄食行为而无需与化学源直接接触的化合物。方法该项目研究了浸渍的纺织材料中的空中通氟菊酯对两种重要疟疾媒介的影响，di按蚊和小按蚊。通过在越南河内的国家卫生与流行病学研究所的半田野环境中的出租车笼内移动来测量驱蚊性。在成年蚊子生物测定笼中测量击倒率和死亡率。在蚊子暴露试验中，在一组子集上收集了定量的空气样本。结果沿距离暴露源的梯度观察到了击倒/死亡率的显着差异，与最远距离（16 m）相比，在2 m和4 m处的击倒/死亡率更高。在地面水平和1.5 m处的击倒/死亡率也高于地面3 m。除了比较2 m和16 m的出租车笼子外，排斥性没有显着差异。重要的是，这两个物种与An对异氟乐灵的反应不同。极小动物更容易击倒和死亡。空气中的氟菌灵的测量浓度范围从检测限以下至1.32 ng / L，但是可评估的样品数量有限，使这些结果的解释变得复杂。结论这项研究测量了越南两种疟疾媒介的驱避性，​​击倒性和死亡率，证明这两种物种均对机载的transfluthrin敏感。在用于大规模媒介控制程序之前，需要进一步研究这两种物种之间反应强度的差异，以描述空间排斥性如何影响杀虫剂抗药性的发展以及对咬人行为的破坏。空气中的氟菌灵的测量浓度范围从检测限以下至1.32 ng / L，但是可评估的样品数量有限，使这些结果的解释变得复杂。结论这项研究测量了越南两种疟疾媒介的驱避性，​​击倒性和死亡率，证明这两种物种均对机载的transfluthrin敏感。在用于大规模媒介控制程序之前，需要进一步研究这两种物种之间反应强度的差异，以描述空间排斥性如何影响杀虫剂抗药性的发展以及对咬人行为的破坏。空气中的氟菌灵的测量浓度范围从检测限以下至1.32 ng / L，但是可评估的样品数量有限，使这些结果的解释变得复杂。结论这项研究测量了越南两种疟疾媒介的驱避性，​​击倒性和死亡率，证明这两种物种均对机载的transfluthrin敏感。在用于大规模媒介控制程序之前，需要进一步研究这两种物种之间反应强度的差异，以描述空间排斥性如何影响杀虫剂抗药性的发展以及对咬人行为的破坏。在越南，两种疟疾媒介的击倒率和死亡率均表明这两种物种均对机载的泛氟素敏感。在用于大规模媒介控制程序之前，需要进一步研究这两种物种之间反应强度的差异，以描述空间排斥性如何影响杀虫剂抗药性的发展以及对咬人行为的破坏。在越南，两种疟疾媒介的击倒率和死亡率均表明这两种物种均对空气中的泛氟素敏感。在用于大规模媒介控制程序之前，需要进一步研究这两种物种之间反应强度的差异，以描述空间排斥性如何影响杀虫剂抗药性的发展以及对咬人行为的破坏。