Reduced bio-efficacy of permethrin EC impregnated bednets against an Anopheles gambiae strain with oxidase-based pyrethroid tolerance -: art. no. 46
Reduced bio-efficacy of permethrin EC impregnated bednets against an Anopheles gambiae strain with oxidase-based pyrethroid tolerance -: art. no. 46
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DOI：
10.1186/1475-2875-3-46
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发表时间：
2004-11-01
期刊：
影响因子：
3
通讯作者：
Manga, L
中科院分区：
文献类型：
--
作者：
Etang, J;Chandre, F;Manga, L
背景：驱虫蚊帐是非洲疟疾控制方案的一个组成部分。疟疾病媒对拟除虫菊酯的抗药性将在多大程度上影响经杀虫剂处理过的蚊帐的效力，这一点存在争议。本研究的目的是评估ITNs对代谢抗性或耐受性疟疾病媒strain.Methods的击倒和杀灭效果：500 mg/m2氯菊酯EC处理的蚊帐对冈比亚按蚊OCEAC实验室（OC-Lab）菌株的生物效力进行了评估。该菌株对DDT具有抗性，对拟除虫菊酯具有耐受性，具有升高的混合功能氧化酶。基苏穆参照敏感株A.冈比亚有限公司用作对照。1998年2月，蚊帐被浸渍，供Ebogo村的家庭使用。然后，在六个月内每月收集它们用于生物测定（WHO锥形试验）。击倒率和死亡率进行了比较的OC-实验室和基苏穆菌株，通过Mantel-Haenszel卡方test.Results：在整个试验期间，氯菊酯EC敲除率是令人印象深刻的（大多数高于97%）。两种菌株之间没有观察到显著差异。然而，与基苏穆菌株的死亡率（75 - 100%）相比，OC-Lab菌株的死亡率（40 - 80%）显著降低。OC-Lab菌株杀灭效果的下降归因于氯菊酯EC耐受性，由于高氧化酶代谢activity.Conclusion：这些数据表明拟除虫菊酯耐受性对ITNs的残留活性的影响。应更多地注意利用生物化学或分子测定法早期检测耐药性，以便更好地进行耐药性管理。
Background: Insecticide-treated nets (ITNs) are an integral component of malaria control programmes in Africa. How much pyrethroid resistance in malaria vectors will impact on the efficacy of ITNs is controversial. The purpose of this study was to evaluate knockdown and killing effects of ITNs on a metabolic-based resistant or tolerant malaria vector strain.Methods: Bio-efficacy of 500 mg/m(2) permethrin EC treated bednets was assessed on the OCEAC laboratory (OC-Lab) strain of Anopheles gambiae s.s.. This strain is resistant to DDT and tolerant to pyrethroids, with elevated mixed function oxidases. The Kisumu reference susceptible strain of A. gambiae s.s. was used as control. Nets were impregnated in February 1998 and used by households of the Ebogo village. Then they were collected monthly over six months for Bio-assays ( WHO cone test). Knockdown and mortality rates were compared between the OC-Lab and the Kisumu strains, by means of the Mantel-Haenszel chi-square test.Results: During the whole trial, permethrin EC knockdown rates were impressive ( mostly higher than 97%). No significant difference was observed between the two strains. However, the mortality rates were significantly decreased in the OC-Lab strain ( 40 - 80%) compared with that of the Kisumu strain ( 75 - 100%). The decrease of killing effect on the OC-Lab strain was attributed to permethrin EC tolerance, due to the high oxidase metabolic activity.Conclusion: These data suggested an impact of pyrethroid tolerance on the residual activity of ITNs. More attention should be given to early detection of resistance using biochemical or molecular assays for better resistance management.