Malaria Consortium - International, London, UK.
Malar J. 2011 Oct 13;10:299. doi: 10.1186/1475-2875-10-299.
Long-lasting insecticidal nets (LLIN) are now standard for the prevention of malaria. However, only products with recommendation for public use from the World Health Organization should be used and this evaluation includes the assessment of net effectiveness after three years of field use. Results for one of the polyester-based products, Interceptor is presented.
In five villages, 190 LLIN and 90 nets conventionally treated with the insecticide alpha-cypermethrin at 25 mg/m2 were distributed randomly and used by the families. Following a baseline household survey a net survey was carried out every six months to capture use, washing habits and physical condition of the nets. Randomly selected nets were collected after 6, 12, 24, 36 and 42 months and tested for remaining insecticide content and ability to knock-down and kill malaria transmitting mosquitoes.
During the three and a half years of observation only 16 nets were lost to follow-up resulting in an estimated attrition rate of 12% after three and 20/% after 3.5 years. Nets were used regularly and washed on average 1.5 times per year. After three and a half years 29% of the nets were still in good condition while 13% were seriously torn with no difference between the LLIN and control nets. The conventionally treated nets quickly lost insecticide and after 24 months only 7% of the original dose remained (1.6 mg/m2). Baseline median concentration of alpha-cypermethrin for LLIN was 194.5 mg/m2 or 97% of the target dose with between and within net variation of 11% and 4% respectively (relative standard deviation). On the LLIN 73.8 mg/m2 alpha-cypermethrin remained after three years of use and 56.2 mg/m2 after three and a half and 94% and 81% of the LLIN still had > 15 mg/m2 left respectively. Optimal effectiveness in bio-assays (≥ 95% 60 minute knock-down or ≥ 80% 24 hour mortality) was found in 83% of the sampled LLIN after three and 71% after three and a half years.
Under conditions in Western Uganda the tested long-lasting insecticidal net Interceptor fulfilled the criteria for phase III of WHO evaluations and, based on preliminary criteria of the useful life, this product is estimated to last on average between three and four years.
长效杀虫蚊帐（LLIN）现在是预防疟疾的标准用品。然而，只有世界卫生组织推荐的公共使用产品才应该被使用，这一评估包括经过三年野外使用后的防虫网有效性的评估。本文呈现的是聚酯基产品Interceptor 的评估结果。
在五个村庄，随机分发 190 顶 LLIN 和 90 顶经过传统杀虫剂 alpha-氯菊酯 25mg/m2 处理的防虫网，供家庭使用。在基线家庭调查后，每六个月进行一次防虫网调查，以捕捉使用、洗涤习惯和防虫网的物理状况。在 6、12、24、36 和 42 个月后，随机收集防虫网，测试剩余杀虫剂含量以及击倒和杀死传播疟疾的蚊子的能力。
在三年半的观察期间，只有 16 顶防虫网失访，估计三年后失访率为 12%，三年半后为 20%。防虫网被定期使用，平均每年洗涤 1.5 次。三年半后，29%的防虫网状况良好，而 13%的防虫网严重撕裂，LLIN 和对照防虫网之间没有差异。传统处理的防虫网很快失去杀虫剂，24 个月后仅残留原剂量的 7%（1.6mg/m2）。LLIN 的 alpha-氯菊酯基线中值浓度为 194.5mg/m2，或目标剂量的 97%，网间和网内分别有 11%和 4%的变异（相对标准偏差）。三年后，LLIN 上仍残留 73.8mg/m2 alpha-氯菊酯，三年半后残留 56.2mg/m2，分别有 94%和 81%的 LLIN 仍残留 > 15mg/m2。在生物测定中发现，83%的抽样 LLIN 在三年后达到了最佳效果（≥95%60 分钟击倒或≥80%24 小时死亡率），而在三年半后，这一比例为 71%。
在乌干达西部的条件下，经过测试的长效杀虫蚊帐Interceptor 符合世界卫生组织第三阶段评估的标准，并且根据有用寿命的初步标准，该产品的估计平均使用寿命为三到四年。
