Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Liverpool L3 5QA, UK.
Department of Biochemistry, Bayero University, PMB 3011 Kano, Nigeria.
Genes (Basel). 2020 Apr 22;11(4):454. doi: 10.3390/genes11040454.
The Nigerian Government is scaling up the distribution of insecticide-treated bed nets for malaria control, but the lack of surveillance data, especially in the Sudan/Sahel region of the country, may hinder targeting priority populations. Here, the vectorial role and insecticide resistance profile of a population of a major malaria vector sensu stricto from Sahel of Nigeria was characterised. s.s. was the only vector found, with a high human blood index (100%) and a biting rate of 5.3/person/night. High infection was discovered (sporozoite rate = 54.55%). The population is resistant to permethrin (mortality = 48.30%, LT = 65.76 min), deltamethrin, DDT (dichlorodiphenyltrichloroethane) and bendiocarb, with mortalities of 29.44%, 56.34% and 54.05%, respectively. Cone-bioassays established loss of efficacy of the pyrethroid-only long-lasting insecticidal nets (LLINs); but 100% recovery of susceptibility was obtained for piperonylbutoxide (PBO)-containing PermaNet3.0. Synergist bioassays with PBO and diethyl maleate recovered susceptibility, implicating CYP450s (permethrin mortality = 78.73%, χ = 22.33, < 0.0001) and GSTs (DDT mortality = 81.44%, χ = 19.12, < 0.0001). A high frequency of 119F mutation (0.84) was observed (OR = 16, χ = 3.40, = 0.05), suggesting the preeminent role of metabolic resistance. These findings highlight challenges associated with deployment of LLINs and indoor residual spraying (IRS) in Nigeria.
尼日利亚政府正在加大力度分发用于疟疾控制的经杀虫剂处理的蚊帐，但缺乏监测数据，特别是在该国苏丹/萨赫勒地区，这可能会阻碍针对重点人群的工作。在此，对来自尼日利亚萨赫勒地区一种主要疟疾媒介按蚊种群的媒介作用和抗药性特征进行了描述。 该种群是唯一发现的媒介，其人体血液指数（100%）和叮咬率（5.3/人/夜）都很高。发现高感染率（孢子体率=54.55%）。该种群对氯菊酯（死亡率=48.30%，LT=65.76 分钟）、溴氰菊酯、DDT（二氯二苯三氯乙烷）和丁醚脲具有抗药性，死亡率分别为 29.44%、56.34%和 54.05%。锥虫生物测定法确定了只含有拟除虫菊酯的长效驱虫蚊帐（LLINs）已经失效；但含有增效醚的 PermaNet3.0 对吡虫啉的敏感性则完全恢复。增效醚和马来酸二乙酯的协同生物测定恢复了敏感性，这表明细胞色素 P450s（氯菊酯死亡率=78.73%，χ=22.33， < 0.0001）和 GSTs（DDT 死亡率=81.44%，χ=19.12， < 0.0001）起作用。观察到 119F 突变（0.84）的高频出现（OR=16，χ=3.40， = 0.05），这表明代谢抗性起主要作用。这些发现突显了在尼日利亚部署长效驱虫蚊帐和室内滞留喷洒（IRS）所面临的挑战。
