Fanello C, Carneiro I, Ilboudo-Sanogo E, Cuzin-Ouattara N, Badolo A, Curtis C F
Department of Tropical and Infectious Diseases, London School of Hygiene and Tropical Medicine, UK.
Med Vet Entomol. 2003 Sep;17(3):333-8. doi: 10.1046/j.1365-2915.2003.00450.x.
Pyrethroid-impregnated bednets and curtains are widely employed to reduce the risk of malaria transmission, but pyrethroid-resistance is becoming more prevalent among malaria vector Anopheles mosquitoes (Diptera: Culicidae). As an alternative treatment for curtains, we assessed carbosulfan (a carbamate insecticide) in comparison with permethrin as the standard pyrethroid, against endophilic female mosquitoes of the Anopheles gambiae Giles complex in a village near Ouagadougou, Burkina Faso. The main criterion evaluated was the impact of curtains (hung inside windows, eaves and doorways) on the number of An. gambiae s.l. females active indoors at night. Light-traps were operated overnight (21.00-06.00 hours beside occupied untreated bednets) to sample mosquitoes in houses fitted with net curtains treated with carbosulfan 0.2 g ai/m2 or permethrin 1 g ai/m2 or untreated, compared with houses without curtains. The treated and untreated curtains significantly reduced the numbers of mosquitoes collected indoors, compared with houses without curtains. Carbosulfan-treated curtains had a highly significantly greater effect than permethrin-treated or untreated curtains, the scale of the difference being estimated as three-fold. However, there was no significant difference between the impact of untreated and permethrin-treated curtains on densities of An. gambiae s.l. trapped indoors. Samples of the An. gambiae complex comprised An. arabiensis Patton and both the S- and M-forms of An. gambiae Giles s.s. Susceptibility tests revealed some resistance to DDT and low frequencies of permethrin-resistance, insufficient to explain the poor performance of permethrin on curtains. Among survivors from the diagnostic dosage of permethrin were some specimens of all three members of the An. gambiae complex, but the kdr resistance mechanism was detected only in the S-form of An. gambiae s.s. Questions arising for further investigation include clarification of resistance mechanisms in, and foraging behaviour of, each member of the An. gambiae complex in this situation and the need to decide whether carbosulfan-treated curtains are acceptably safe for use to reduce risks of malaria transmission.
拟除虫菊酯浸渍蚊帐和窗帘被广泛用于降低疟疾传播风险，但拟除虫菊酯抗性在传疟媒介按蚊（双翅目：蚊科）中越来越普遍。作为窗帘的替代处理方法，我们在布基纳法索瓦加杜古附近的一个村庄，评估了丁硫克百威（一种氨基甲酸酯类杀虫剂）与作为标准拟除虫菊酯的氯菊酯相比，对冈比亚按蚊吉尔斯复合体嗜室内雌蚊的效果。评估的主要标准是窗帘（挂在窗户、屋檐和门口内）对夜间在室内活动的冈比亚按蚊指名亚种雌蚊数量的影响。在配备有经0.2 g有效成分/平方米丁硫克百威或1 g有效成分/平方米氯菊酯处理的网帘或未处理网帘的房屋中，与没有窗帘的房屋相比，在有人居住的未处理蚊帐旁（21:00 - 06:00时）通宵操作灯光诱捕器来采集蚊子样本。与没有窗帘的房屋相比，经处理和未处理的窗帘都显著减少了室内采集到的蚊子数量。经丁硫克百威处理的窗帘比经氯菊酯处理或未处理的窗帘效果显著更好，差异程度估计为三倍。然而，未处理和经氯菊酯处理的窗帘对室内诱捕到的冈比亚按蚊指名亚种密度的影响没有显著差异。冈比亚按蚊复合体样本包括阿拉伯按蚊帕顿以及冈比亚按蚊指名亚种的S型和M型。敏感性测试显示对滴滴涕有一定抗性，对氯菊酯抗性频率较低，不足以解释氯菊酯在窗帘上效果不佳的原因。在氯菊酯诊断剂量的存活者中，有冈比亚按蚊复合体所有三个成员的一些样本，但仅在冈比亚按蚊指名亚种的S型中检测到击倒抗性机制。需要进一步研究的问题包括明确在这种情况下冈比亚按蚊复合体每个成员的抗性机制和觅食行为，以及需要确定经丁硫克百威处理的窗帘用于降低疟疾传播风险是否具有可接受的安全性。
