Faculté de Médecine, Université de Bandundu, B.P 548 Bandundu-ville, Bandundu, République Démocratique de Congo.
Institut National de Recherche Biomédicale, B.P 1197 KIN 1, Kinshasa, République Démocratique de Congo.
Pan Afr Med J. 2021 Oct 25;40:118. doi: 10.11604/pamj.2021.40.118.27365. eCollection 2021.
insecticide-treated nets (ITNs) remain the mainstay of malaria vector control in the Democratic Republic of Congo. However, insecticide resistance of malaria vectors threatens their effectiveness. Entomological inoculation rates and insecticide susceptibility in Anopheles gambiae s.l. were evaluated before and after mass distribution of ITNs in Bandundu City for possible occurrence of resistance.
a cross-sectional study was conducted from 15 July 2015 to 15 June 2016. Adult mosquitoes were collected using pyrethrum spray catches and human landing catches and identified to species level and tested for the presence of sporozoites. Bioassays were carried out before and after distribution of ITNs to assess the susceptibility of adult mosquitoes to insecticides. Synergist bioassays were also conducted and target site mutations assessed using Polymerase chain reaction (PCR).
a total of 1754 female An. gambiae s.l. were collected before and after deployment of ITNs. Fewer mosquitoes were collected after the distribution of ITNs. However, there was no significant difference in sporozoite rates or the overall entomological inoculation rate before and after the distribution of ITNs. Test-mosquitoes were resistant to deltamethrin, permethrin, and Dichlorodiphenyltrichloroethane but susceptible to bendiocarb. Pre-exposure of mosquitoes to Piperonyl butoxide increased their mortality after exposure to permethrin and deltamethrin. The frequency of the Kinase insert domain receptor (kdr)-West gene increased from 92 to 99% before and after the distribution of nets, respectively.
seasonal impacts could be a limiting factor in the analysis of these data; however, the lack of decrease in transmission after the distribution of new nets could be explained by the high-level of resistance to pyrethroid.
在刚果民主共和国，经杀虫剂处理的蚊帐（ITN）仍然是疟疾媒介控制的主要手段。然而，疟疾传播媒介对杀虫剂的抗药性威胁到它们的有效性。在班顿杜市大规模分发 ITN 前后，评估了冈比亚按蚊（Anopheles gambiae s.l.）的昆虫接种率和杀虫剂敏感性，以确定是否存在抗药性。
一项横断面研究于 2015 年 7 月 15 日至 2016 年 6 月 15 日进行。使用拟除虫菊酯喷雾捕获和人降落捕获法收集成年蚊子，并进行种属鉴定和疟原虫孢子检测。在分发 ITN 前后进行生物测定，以评估成蚊对杀虫剂的敏感性。还进行了增效生物测定，并使用聚合酶链反应（PCR）评估靶位突变。
共收集了 1754 只雌性冈比亚按蚊（An. gambiae s.l.），分别在分发 ITN 前后。分发 ITN 后收集的蚊子数量较少。然而，分发 ITN 前后的疟原虫率或总体昆虫接种率没有显著差异。试验蚊子对氯菊酯、氯菊酯和滴滴涕具有抗药性，但对苯氧威敏感。蚊子在接触氯菊酯和氯氰菊酯之前接触胡椒基丁醚会增加其死亡率。激酶插入域受体（kdr）-West 基因的频率在分发网前后分别从 92%增加到 99%。
季节性影响可能是分析这些数据的一个限制因素；然而，新分发的网后传播没有减少，这可能是由于对拟除虫菊酯的高水平抗性所致。
