Parker J E A, Kakilla C, Nelwin K, Kroner C, Logan R, Ismail H M, Towers C, Manjurano A, Towers D, McCall P J
Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
National Institute of Medical Research, Mwanza, Tanzania.
R Soc Open Sci. 2024 May 29;11(5):231165. doi: 10.1098/rsos.231165. eCollection 2024 May.
Insecticide-treated nets (ITNs) are the most effective method for malaria prevention in Africa. Using near-infrared video tracking in a laboratory environment, we recorded and assessed bednet entry and exit by a northern Tanzanian population of at a human-occupied untreated net and a PermaNet® 2.0 ITN. Both had 12 holes, each 10 cm in diameter, punctured at specific locations, and the ITN was washed 20 times to further simulate the wear and tear of ageing. Washing reduced the insecticide content of ITNs by 61%, which then showed similar rates to the untreated nets for net entry (39% entered untreated net and 41% entered ITN; = 0.84) and exit (37% and 43%, respectively; 0.67). Regardless of treatment, approximately 40% of mosquitoes entered nets within 20 s of first appearing in the field of view and reached the volunteer's skin within 5 s of entering the net. Mortality rates post-exposure were significantly higher ( 0.048) at ITNs (26.6%; 95% CI 13.4%-39.7%) than at untreated controls (6.4%; 95% CI 1.8%-14.6%). The washed and aged ITN provided little additional personal protection for the sleeper over an untreated net. Simple adjustments to materials and design that could extend the effective lifespan of ITNs are discussed.
经杀虫剂处理的蚊帐（ITNs）是非洲预防疟疾最有效的方法。在实验室环境中，我们使用近红外视频跟踪技术，记录并评估了坦桑尼亚北部人群在未处理蚊帐和长效驱虫蚊帐PermaNet® 2.0中的进出情况。两种蚊帐都在特定位置有12个直径为10厘米的洞，并且对长效驱虫蚊帐进行了20次洗涤，以进一步模拟老化的磨损情况。洗涤使长效驱虫蚊帐的杀虫剂含量降低了61%，然后其进入蚊帐（39%进入未处理蚊帐，41%进入长效驱虫蚊帐；P = 0.84）和离开蚊帐（分别为37%和43%；P = 0.67）的比例与未处理蚊帐相似。无论是否经过处理，约40%的蚊子在首次出现在视野内20秒内进入蚊帐，并在进入蚊帐后5秒内到达志愿者皮肤。暴露后，长效驱虫蚊帐的死亡率（26.6%；95%置信区间13.4%-39.7%）显著高于未处理对照组（6.4%；95%置信区间1.8%-14.6%）（P = 0.048）。经过洗涤和老化的长效驱虫蚊帐为睡眠者提供的额外个人防护几乎不比未处理蚊帐多。本文讨论了对材料和设计进行简单调整以延长长效驱虫蚊帐有效使用寿命的方法。
