LLIN Evaluation in Uganda Project (LLINEUP) – The durability of long-lasting insecticidal nets treated with and without piperonyl butoxide (PBO) in Uganda
LLIN Evaluation in Uganda Project (LLINEUP) – The durability of long-lasting insecticidal nets treated with and without piperonyl butoxide (PBO) in Uganda
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乌干达 LLIN 评估项目 (LLINEUP) – 乌干达经或不含胡椒基丁醚 (PBO) 处理的长效杀虫蚊帐的耐久性
DOI：
10.1101/2022.02.17.480046
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
A. Lynd
中科院分区：
文献类型：
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作者：
F. Mechan;Agaba Katureebe;Violet Tuhaise;Martin Mugote;Ambrose Oruni;Ismail Onyige;Kawesa Bumali;Jonathan Thornton;Kilama Maxwell;Mary Kyohere;M. Kamya;Peter Mutungi;Simon P. Kigozi;Adoke Yeka;J. Opigo;Catherine Maiteki;S. Gonahasa;J. Hemingway;G. Dorsey;L. Reimer;S. Staedke;M. Donnelly;A. Lynd
由于对拟除虫菊酯类杀虫剂的抗药性日益增加，已经开发出了增效剂胡椒酰丁醇的长效杀虫蚊帐，但其在田间的耐久性仍然缺乏描述。在乌干达2017-2018年的分布中嵌入了一项实用的集群随机试验，以比较有PBO和没有PBO的LLIN的持久性。总共包括104个集群，每个集群使用四种LLIN产品中的一种，两个使用拟除虫菊酯+PBO (Olyset Plus和PermaNet 3.0)，两个仅使用拟除虫菊酯（Olyset Net和PermaNet 2.0）。蚊帐在分发后的基线、12个月和25个月取样，以评估其物理状况、化学成分和生物功效。物理状态用比例孔指数定量，化学含量用高效液相色谱测定。采用抗拟除虫菊酯的三分钟WHO Cone和Wireball测定法评估生物功效。冈比亚，1小时基因敲除，24小时死亡。评估的LLIN产品在物理耐久性方面没有差异（p=0.644）。所有产品的拟除虫菊酯含量在各时间点保持相对稳定，但PBO含量分别在Olyset Plus和PermaNet 3.0中下降了55% （p<0.001）和58% （p<0.001）。这两种PBO LLINs对新的拟除虫菊酯抗性蚊子非常有效，可以击倒所有蚊子。然而，随着时间的推移，生物功效下降，25个月后，Olyset Plus降低45.72% (95% CI: 22.84-68.62, p=0.021), Permanet 3.0降低78.57% （95% CI: 63.57-93.58, p<0.001）。在这里，我们证明了Olyset Plus和PermaNet 3.0与它们的纯拟除虫菊酯等效物一样耐用，并且对耐拟除虫菊酯的An具有优越的生物功效。冈比亚按蚊。然而，PBO- llins的优势随着操作使用而下降，与总PBO含量的减少有关。仅仅两年后生物功效的下降令人担忧，迫切需要评估PBO LLINs在其他环境中的耐久性。
Long Lasting Insecticidal Nets (LLINs) supplemented with the synergist piperonyl butoxide have been developed in response to growing pyrethroid resistance however their durability in the field remains poorly described. A pragmatic cluster-randomised trial was embedded into Uganda’s 2017-2018 distribution to compare the durability of LLINs with and without PBO A total of 104 clusters were included with each receiving one of four LLIN products, two with pyrethroid+PBO (Olyset Plus and PermaNet 3.0) and two pyrethroid-only (Olyset Net and PermaNet 2.0). Nets were sampled at baseline, 12, and 25 months post-distribution to assess physical condition, chemical content, and bioefficacy. Physical condition was quantified using proportionate Hole Index and chemical content measured using high-performance liquid chromatography. Bioefficacy was assessed with three-minute WHO Cone and Wireball assays using pyrethroid-resistant An. gambiae, with 1hr knockdown and 24hr mortality recorded. There was no difference in physical durability between LLIN products assessed (p=0.644). The pyrethroid content of all products remained relatively stable across timepoints but PBO content declined by 55% (p<0.001) and 58% (p<0.001) for Olyset Plus and PermaNet 3.0 respectively. Both PBO LLINs were highly effective against pyrethroid-resistant mosquitoes when new, knocking down all mosquitoes. However, bioefficacy declined over time with Olyset Plus knocking down 45.72% (95% CI: 22.84-68.62, p=0.021) and Permanet 3.0 knocking down 78.57% (95% CI: 63.57-93.58, p<0.001) after 25 months. Here we demonstrate that both Olyset Plus and PermaNet 3.0 are as durable as their pyrethroid-only equivalents and had superior bioefficacy against pyrethroid-resistant An. gambiae. However, the superiority of PBO-LLINs decreased with operational use, correlating with a reduction in total PBO content. This decline in bioefficacy after just two years is concerning and there is an urgent need to assess the durability of PBO LLINs in other settings.