Bobanga Thierry, Ayieko Wycliff, Zanga Mimie, Umesumbu Solange, Landela Ange, Fataki Olivier, Mandoko Alain Serge, Tshibamba Jacques, Nyabola Lambert
Department of Tropical Medicine, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.
J Vector Borne Dis. 2013 Sep;50(3):206-14.
BACKGROUND & OBJECTIVES: Insecticide resistance in mosquitoes at Kinshasa may jeopardize the efficacy and usage of long-lasting insecticidal nets (LLINs). Entomological impact, user acceptance and bioefficacy of a combination LLIN (PermaNet® 3.0) and a standard LLIN (OlysetNet®) were evaluated at two sites in Kinshasa characterized by high densities of either Anopheles gambiae s.s. (Kindele) or Culex spp (Kimbangu).
Insecticide susceptibility (permethrin, deltamethrin, bendiocarb, propoxur and DDT) was determined via tube tests and bottle assays. Entomological impact of unwashed and washed LLINs and untreated nets was assessed via Latin square, based on rotation of nets and their users through selected houses at each site. User acceptability was evaluated through interviews using a questionnaire and net bioefficacy was measured via cone bioassays with field-derived An. gambiae s.s.
The An. gambiae s.s. population from Kindele was resistant to DDT and permethrin with mortality rate of 27.3 and 75.8%, respectively, and kdr mutations (L1014F) plus suspected metabolic resistance. The Culex spp population was resistant to all five insecticides tested. No differences in entomological indices were observed for the five net treatments, but bioefficacy against An. gambiae was significantly higher for unwashed and washed PermaNet 3.0 (100 and 71% mortality) than for OlysetNet (56 and 36%). Householders reported a good sleep most often when using unwashed and washed PermaNet (94 and 88%) and least often with unwashed OlysetNet (46%).
INTERPRETATION & CONCLUSION: High bioefficacy via cone bioassays against an An. gambiae s.s. population with kdr and suspected metabolic resistance was observed with PermaNet 3.0. Lower biting rates and a higher chance of a good night of sleep were reported when using PermaNet 3.0 compared to OlysetNet.
金沙萨的蚊子对杀虫剂产生抗性可能会危及长效杀虫蚊帐（LLINs）的功效及使用。在金沙萨两个以高密度冈比亚按蚊（冈比亚按蚊指名亚种，金代勒地区）或库蚊（金班古地区）为特征的地点，评估了组合式LLIN（长效蚊帐3.0）和标准LLIN（奥力赛蚊帐）的昆虫学影响、用户接受度及生物功效。
通过试管试验和瓶试法测定杀虫剂敏感性（氯菊酯、溴氰菊酯、残杀威、残杀畏和滴滴涕）。基于蚊帐及其使用者在各地点选定房屋中的轮换情况，通过拉丁方评估未清洗和已清洗的LLIN以及未处理蚊帐的昆虫学影响。通过问卷调查访谈评估用户接受度，并通过对野外采集的冈比亚按蚊指名亚种进行锥形生物测定来测量蚊帐生物功效。
来自金代勒地区的冈比亚按蚊指名亚种群体对滴滴涕和氯菊酯具有抗性，死亡率分别为27.3%和75.8%，存在kdr突变（L1014F）以及疑似代谢抗性。库蚊群体对所测试的所有五种杀虫剂均具有抗性。五种蚊帐处理方式的昆虫学指标未观察到差异，但未清洗和已清洗的长效蚊帐3.0对冈比亚按蚊的生物功效（死亡率分别为100%和71%）显著高于奥力赛蚊帐（分别为56%和36%）。户主报告称，使用未清洗和已清洗的长效蚊帐时睡眠良好的频率最高（分别为94%和88%），而使用未清洗的奥力赛蚊帐时睡眠良好的频率最低（46%）。
通过锥形生物测定观察到，长效蚊帐3.0对具有kdr和疑似代谢抗性的冈比亚按蚊指名亚种群体具有较高的生物功效。与奥力赛蚊帐相比，使用长效蚊帐3.0时报告的叮咬率较低，且有更高的几率睡个好觉。
