Chaumeau Victor, Cerqueira Dominique, Zadrozny John, Kittiphanakun Praphan, Andolina Chiara, Chareonviriyaphap Theeraphap, Nosten François, Corbel Vincent
Centre hospitalier universitaire de Montpellier, Montpellier, France.
Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France.
Parasit Vectors. 2017 Mar 31;10(1):165. doi: 10.1186/s13071-017-2102-z.
There is a paucity of data about the susceptibility status of malaria vectors to Public Health insecticides along the Thailand-Myanmar border. This lack of data is a limitation to guide malaria vector-control in this region. The aim of this study was to assess the susceptibility status of malaria vectors to deltamethrin, permethrin and DDT and to validate a simple molecular assay for the detection of knock-down resistance (kdr) mutations in the study area.
Anopheles mosquitoes were collected in four sentinel villages during August and November 2014 and July 2015 using human landing catch and cow bait collection methods. WHO susceptibility tests were carried out to measure the mortality and knock-down rates of female mosquitoes to deltamethrin (0.05%), permethrin (0.75%) and DDT (4%). DNA sequencing of a fragment of the voltage-gated sodium channel gene was carried out to identify knock-down resistance (kdr) mutations at position 1014 in mosquitoes surviving exposure to insecticides.
A total of 6295 Anopheles belonging to ten different species were bioassayed. Resistance or suspected resistance to pyrethroids was detected in An. barbirostris (s.l.) (72 and 84% mortality to deltamethrin (n = 504) and permethrin (n = 493) respectively), An. hyrcanus (s.l.) (33 and 48% mortality to deltamethrin (n = 172) and permethrin (n = 154), respectively), An. jamesii (87% mortality to deltamethrin, n = 111), An. maculatus (s.l.) (85 and 97% mortality to deltamethrin (n = 280) and permethrin (n = 264), respectively), An. minimus (s.l.) (92% mortality, n = 370) and An. vagus (75 and 95% mortality to deltamethrin (n =148) and permethrin (n = 178), respectively). Resistance or suspected resistance to DDT was detected in An. barbirostris (s.l.) (74% mortality, n = 435), An. hyrcanus (s.l.) (57% mortality, n = 91) and An. vagus (97% mortality, n = 133). The L1014S kdr mutation at both heterozygous and homozygous state was detected only in An. peditaeniatus (Hyrcanus Group).
Resistance to pyrethroids is present along the Thailand-Myanmar border, and it represents a threat for malaria vector control. Further investigations are needed to better understand the molecular basis of insecticide resistance in malaria vectors in this area.
泰国-缅甸边境地区关于疟疾媒介对公共卫生杀虫剂的易感性状况的数据匮乏。数据的缺失限制了该地区疟疾媒介控制工作的开展。本研究旨在评估疟疾媒介对溴氰菊酯、氯菊酯和滴滴涕的易感性状况，并验证一种用于检测研究区域击倒抗性（kdr）突变的简单分子检测方法。
2014年8月至11月以及2015年7月期间，在4个哨点村庄使用人饵诱捕法和牛饵诱捕法收集按蚊。进行了世界卫生组织易感性试验，以测定雌性蚊子对溴氰菊酯（0.05%）、氯菊酯（0.75%）和滴滴涕（4%）的死亡率和击倒率。对电压门控钠通道基因片段进行DNA测序，以鉴定接触杀虫剂后存活的蚊子中第1014位的击倒抗性（kdr）突变。
共对属于10个不同种类的6295只按蚊进行了生物测定。在巴拉巴按蚊（复合组）（对溴氰菊酯（n = 504）和氯菊酯（n = 493）的死亡率分别为72%和84%）、赫坎按蚊（复合组）（对溴氰菊酯（n = 172）和氯菊酯（n = 154）的死亡率分别为33%和48%）、吉氏按蚊（对溴氰菊酯的死亡率为87%，n = 111）、多斑按蚊（复合组）（对溴氰菊酯（n = 280）和氯菊酯（n = 264）的死亡率分别为85%和97%）、微小按蚊（复合组）（死亡率为92%，n = 370）和迷走按蚊（对溴氰菊酯（n = 148）和氯菊酯（n = 178）的死亡率分别为75%和95%）中检测到对拟除虫菊酯的抗性或疑似抗性。在巴拉巴按蚊（复合组）（死亡率为74%，n = 435）、赫坎按蚊（复合组）（死亡率为57%，n = 91）和迷走按蚊（死亡率为97%，n = 133）中检测到对滴滴涕的抗性或疑似抗性。仅在带足按蚊（赫坎按蚊组）中检测到杂合和纯合状态的L1014S kdr突变。
泰国-缅甸边境地区存在对拟除虫菊酯的抗性，这对疟疾媒介控制构成威胁。需要进一步开展调查，以更好地了解该地区疟疾媒介中杀虫剂抗性的分子基础。
