Following guidance from the US President’s Malaria Initiative, durability monitoring of DawaPlus® 2.0 brand of long-lasting insecticidal net (LLIN) distributed during the 2015/16 mass campaign was set up in three ecologically different states: Zamfara, Ebonyi and Oyo. This was a prospective cohort study of representative samples of households from each location, recruited at baseline, 1 to 6 months after the mass campaign. All campaign nets in the households were labelled and followed up over a period of 36 months in Zamfara and Ebonyi and 24 months in Oyo. Primary outcome was the “proportion of nets surviving in serviceable condition” based on attrition and integrity measures and the median survival in years. The outcome for insecticidal durability was determined by bio-assay from sub-samples of campaign nets. A total of 439 households (98% of target) and 1096 campaign nets (106%) were included in the study. Definite outcomes could be determined for 92% of the cohort nets in Zamfara, 88% in Ebonyi and 75% in Oyo. All-cause attrition was highest in Oyo with 47% no longer present after 24 months, 53% in Ebonyi and 28% in Zamfara after 36 months. Overall only 1% of all campaign nets were used for other purposes. Estimated survival in serviceable condition of the campaign nets was 80% in Zamfara, 55% in Ebonyi (36 months follow-up) and 75% in Oyo (24 months follow-up) corresponding to median survival of 5.3, 3.3, 3.2 years, respectively. Factors associated with better survival were exposure to social messaging combined with a positive net-care attitude and only adult users. Failing to fold the net when hanging and having children under 5 years of age in the household negatively impacted net survival. Insecticidal effectiveness testing at final survey showed knock-down rates of 50–69%, but 24-h mortality above 95% resulting in 100% optimal performance in Ebonyi and Oyo and 97% in Zamfara. Results confirm the strong influence of net-use environment and behavioural factors in the physical survival of the same LLIN brand, which can increase the time until 50% of nets are no longer serviceable by up to 2 years.

中文翻译：

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监控长效驱虫净DawaPlus的物理和杀虫耐久性^® 2.0在三个国家在尼日利亚

在美国总统疟疾倡议的指导下，在三个生态不同的州（赞法拉州，埃邦尼州和奥约州）建立了DawaPlus®2.0品牌长效杀虫网（LLIN）在2015/16大规模运动期间分发的耐久性监测。这是前瞻性队列研究，该研究是在大规模运动后1至6个月从基线收集的每个地点的代表性家庭样本的。在扎姆法拉（Zamfara）和埃博尼（Ebonyi）进行了为期36个月的跟踪调查，在奥约（Oyo）进行了24个月的跟踪跟踪了住户中所有的竞选网。主要结果是基于损耗和完整性测量的“网状结构在可使用条件下生存的比例”以及中位生存期（以年为单位）。杀虫剂耐久性的结果是通过运动网子样品的生物测定确定的。该研究总共包括439户家庭（目标的98％）和1096个竞选网（106％）。可以确定Zamfara的92％的队列网络，Ebonyi的88％和Oyo的75％的队列结果是肯定的。Oyo的全因损耗是最高的，在24个月后不再存在47％，Ebonyi为53％，在Zamfara为36％后出现28％。总体而言，所有竞选网中只有1％用于其他目的。战役网的可用状态估计生存率在Zamfara为80％，在Ebonyi为55％（随访36个月），在Oyo为75％（随访24个月），对应的中位生存期为5.3、3.3、3.2年，分别。与更好的生存相关的因素是接触社交消息，积极的网络护理态度以及仅成人用户。吊网时无法折叠网，并且家庭中有5岁以下的儿童会对网的生存造成负面影响。最终调查中的杀虫效力测试表明，其击倒率为50-69％，但24小时死亡率高于95％，导致Ebonyi和Oyo的最佳性能为100％，Zamfara为97％。结果证实了网络使用环境和行为因素对同一LLIN品牌的物理存活率的强烈影响，这可能会增加50％的蚊帐不再使用2年的时间。