期刊
MEDICAL AND VETERINARY ENTOMOLOGY
卷 15, 期 1, 页码 105-112出版社
WILEY-BLACKWELL
DOI: 10.1046/j.1365-2915.2001.00288.x
关键词
Anopheles gambiae; Culex quinquefasciatus; Mansonia; bednets; carbamate; carbosulfan; combined treatment; insecticide resistance; insecticide-treated nets (ITNs); malaria vector; mixtures; mosquito nets; nuisance mosquitoes; pyrethroid; resistance management; vector control; verandah-trap; Cote d'Ivoire
A new approach is proposed in the treatment of mosquito nets, using a 'two-in-one' combination of pyrethroid and non-pyrethroid insecticides applied to different parts of bednets, The objectives are mainly to overcome certain limitations of pyrethroid-impregnated bednets currently recommended for malaria control purposes. Apart from developing alternatives to pyrethroid dependency, we sought to counteract pyrethroid irritant effects on mosquitoes (excito-repellency) and resistance to pyrethroids. The idea takes advantage of the presumed host-seeking behaviour of mosquitoes confronted by a net draped over a bed, whereby the mosquito may explore the net from the top downwards. Thus, nets could be more effective if treated on the upper part with residual non-irritant insecticide (carbamate or organophosphate) and with a pyrethroid on the lower part. Sequential exposure to different insecticides with distinct modes of action is equivalent to the use of a mixture as a potential method of managing insecticide resistance. We also intended to improve the control of nuisance mosquitoes, especially Culex quinquefasciatus Say (Diptera: Culicidae) that often survive pyrethroids. in order to encourage public compliance with use of insecticide-treated nets (ITNs). Polyester bednets were pretreated with residual pyrethroid (bifenthrin 50 mg/m(2) or deltamethrin 25 mg/m(2)) on the lower half and with carbamate (carbosulfan 300 mg/m(2)) on the upper half to minimize contact with net users. Unreplicated examples of these 'two-in-one' treated nets were field-tested against wild mosquitoes, in comparison with an untreated net and bednets treated with each insecticide alone, including PermaNet(TM) wash-resistant formulation of deltamethrin 50 mg/m(2). Overnight tests involved volunteers sleeping under the experimental bednets in verandah-trap huts at Yaokofikro, near Bouake in Cote d'Ivoire, where the main malaria vector Anopheles gambiae Giles, as well as Culex quinquefasciatus Say, are highly resistant to pyrethroids. Efficacy of these ITNs was assessed in the huts by four entomological criteria: deterrency and induced exophily (effects on hut entry and exit), blood-feeding and mortality rates (immediate and delayed). Overall, the best impact was achieved by the bednets treated with carbosulfan alone, followed by 'two-in-one' treatments with carbosulfan plus pyrethroid. Blood-feeding rates were 13% An. gambiae and 17% Cx, quinquefasciatus in huts with untreated nets, but only 3% with carbosulfan ITNs, 7-11% with combined ITN treatment, 6-8% An. gambiae and 12-14% Cx. quinquefasciatus with pyrethroid alone. Mosquitoes that entered the huts were killed sooner by nets with combined treatment than by pyrethroid alone. Mortality-rates in response to ITNs with carbosulfan (alone or combined with pyrethroid) were significantly greater for Cx. quinquefasciatus. but not for An. gambiae, compared to ITNs with only pyrethroid. About 20% of sleepers reported potential side-effects (headache and/or sneezing) from use of ITN treated with carbosulfan alone. Further development of this new 'two-in-one' ITN concept requires a range of investigations (choice of effective products, cost-benefit analysis, safety, etc.) leading to factory production of wash-resistant insecticidal nets treated with complementary insecticides.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据