评价塞内加尔 5 种长效驱虫蚊帐（LLINs）的残余功效和物理耐久性。

Evaluation of the residual efficacy and physical durability of five long-lasting insecticidal nets (LLINs) in Senegal.

机构信息

Laboratoire d'Ecologie Vectorielle et Parasitaire, Département de Biologie Animal, Faculté Des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Sénégal.

Division of Parasitic Diseases and Malaria, Centers for Disease Control (CDC) and Prevention, Atlanta, GA, USA.

出版信息

Malar J. 2022 Jul 2;21(1):210. doi: 10.1186/s12936-022-04230-6.

BACKGROUND

The preventive and curative strategies of malaria are based on promoting the use of long-lasting insecticidal nets (LLINs) and treating confirmed cases with artemisinin-based combination therapy. These strategies have led to a sharp decline in the burden of malaria, which remains a significant public health problem in sub-Saharan countries. The objective of this study was to determine and compare the residual efficacy of LLINs recommended by the World Health Organization.

METHODS

The study was conducted in six villages in two sites in Senegal located in the Sahelo-Sudanian area of the Thiès region, 70 km from Dakar and in Mbagame, a semi-urban zone in the Senegal River Valley. A census was conducted of all sleeping places in each household to be covered by LLINs. Five brands of LLIN were distributed, and every six months, retention rates, net use, maintenance, physical integrity, insecticide chemical content, and biological efficacy were examined for each type of LLIN.

RESULTS

A total of 3012 LLINs were distributed in 1249 households in both sites, with an average coverage rate of 94% (95% CI 92.68-95.3). After 36 months, the average retention rate was 12.5% and this rate was respectively 20.5%, 15.1%, 10%, 7%, and 3% for Olyset Net, Dawa Plus 2.0, PermaNet 2.0, NetProtect and Life Net, respectively. The proportion of LLINs with holes and the average number of holes per mosquito net increased significantly during each follow-up, with a large predominance of size 1 (small) holes for all types of LLINs distributed. During the three-year follow-up, bioassay mortality rates of a susceptible strain of insectary reared Anopheles coluzzii decreased in the following net types: in Dawa Plus 2.0 (100% to 51.7%), PermaNet 2.0 (96.6% to 83%), and Olyset Net (96.6% to 33.3%). Mortality rates remained at 100% in Life Net over the same time period. After 36 months, the average insecticide content per brand of LLIN decreased by 40.9% for Dawa Plus 2.0, 31% for PermaNet 2.0, 39.6% for NetProtect and 51.9% for Olyset Net and 40.1% for Life Net.

CONCLUSIONS

Although some net types retained sufficient insecticidal activity, based on all durability parameters measured, none of the net types survived longer than 2 years.

背景

疟疾的预防和治疗策略基于推广使用长效驱虫蚊帐（LLINs）和用青蒿素为基础的联合疗法治疗确诊病例。这些策略导致疟疾负担急剧下降，但在撒哈拉以南国家，疟疾仍然是一个重大的公共卫生问题。本研究的目的是确定和比较世界卫生组织推荐的 LLINs 的残留效果。

方法

这项研究在塞内加尔的两个地点的六个村庄进行，这两个地点位于达喀尔 70 公里处的 Thiès 地区的萨赫勒-苏丹地区和塞内加尔河谷的半城市 Mbagame。对每个家庭中所有将被 LLINs 覆盖的睡眠场所进行了普查。分发了五种品牌的 LLINs，每六个月检查一次每种 LLIN 的保留率、网的使用、维护、物理完整性、杀虫剂化学成分和生物功效。

结果

在两个地点的 1249 户家庭中，共分发了 3012 顶 LLINs，覆盖率平均为 94%（95%置信区间 92.68-95.3）。36 个月后，平均保留率为 12.5%，分别为 Olyset Net、Dawa Plus 2.0、PermaNet 2.0、NetProtect 和 Life Net 的 20.5%、15.1%、10%、7%和 3%。在每次随访中，LLINs 上的洞的比例和每顶蚊帐上的平均洞数都显著增加，所有分发的 LLINs 都以尺寸 1（小）的洞为主。在三年的随访期间，实验室饲养的敏感品系按蚊（Anopheles coluzzii）的生物测定死亡率在以下几种蚊帐类型中下降：在 Dawa Plus 2.0（100%降至 51.7%）、PermaNet 2.0（96.6%降至 83%）和 Olyset Net（96.6%降至 33.3%）。在同一时期，Life Net 的死亡率仍保持 100%。36 个月后，每顶 LLIN 品牌的杀虫剂含量平均下降 40.9%的 Dawa Plus 2.0、31%的 PermaNet 2.0、39.6%的 NetProtect、51.9%的 Olyset Net 和 40.1%的 Life Net。