Chung Han-Hsuan, Teng Hwa-Jen, Huang Chin-Gi, Tsai I-Jung, Chen Hung-Jui, Komagata Osamu, Kasai Shinji, Tsai Kun-Hsien, Chen Shiu-Ling
Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan.
Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan.
PLoS Negl Trop Dis. 2025 Jan 6;19(1):e0012768. doi: 10.1371/journal.pntd.0012768. eCollection 2025 Jan.
Aedes aegypti transmits various arthropod-borne diseases such as dengue, posing a significant burden to public health in tropical and subtropical regions. Pyrethroid-based control strategies are effective in managing this vector; however, the development of insecticide resistance has hindered these efforts. Hence, long-term monitoring of insecticide resistance in mosquito populations is crucial for effective vector and disease control.
METHODOLOGY/PRINCIPAL FINDINGS: In this study, we identified insecticide resistance due to a voltage-gated sodium channel (vgsc) mutation in Ae. aegypti in Taiwan between 2016 and 2023. In total, 1,761 field-caught Ae. aegypti samples from Tainan, Kaohsiung, and Pingtung were genotyped. The frequencies of S989P, V1016G, T1520I, F1534C, and D1763Y amino acid variants increased over the surveillance period. A T1520I mutation was detected for the first time and has since rapidly spread throughout Taiwan. The triple-mutant haplotype PGTFY was first documented in Ae. aegypti. Moreover, the unmutated haplotype vanished in Taiwan, suggesting that the vgsc mutations were fixed in local populations of Ae. aegypti. Five resistance-associated genotypes, SVTCD/SVTCD, SGTFY/PGTFD, SVTCD/SGTFY, PGTFD/PGTFD, and SVTCD/PGTFD, exhibited an increased frequency and accounted for 76% of the total field population. We also detected the resistant genotype SVICD/PGTFD, and its frequency increased 13-fold in the field between 2016 and 2023. Moreover, we also observed that mutations differed geographically, with S989P mainly found in Kaohsiung and V1016G in Kaohsiung and Pingtung. The frequency of T1520I was noticeably higher in Kaohsiung, and D1763Y occurred mainly in Tainan.
CONCLUSIONS/SIGNIFICANCE: The emergence and expansion of mutations along with the disappearance of wild-type mosquitoes in Taiwan underscores the threat of resistance and difficulty of mosquito control in Taiwan as well as globally. This study determined the insecticide resistance status of Ae. aegypti in Taiwan, and the findings will be helpful for resistance monitoring in areas where pyrethroids are used to control Ae. aegypti.
埃及伊蚊传播多种虫媒疾病，如登革热，给热带和亚热带地区的公共卫生带来了沉重负担。基于拟除虫菊酯的控制策略在管理这种病媒方面是有效的；然而，杀虫剂抗性的发展阻碍了这些努力。因此，长期监测蚊虫种群中的杀虫剂抗性对于有效的病媒和疾病控制至关重要。
方法/主要发现：在本研究中，我们在2016年至2023年期间在台湾地区的埃及伊蚊中鉴定出由于电压门控钠通道（vgsc）突变导致的杀虫剂抗性。总共对来自台南、高雄和屏东的1761份野外捕获的埃及伊蚊样本进行了基因分型。在监测期间，S989P、V1016G、T1520I、F1534C和D1763Y氨基酸变体的频率增加。首次检测到T1520I突变，此后迅速在台湾地区传播。三突变单倍型PGTFY首次在埃及伊蚊中被记录。此外，未突变的单倍型在台湾地区消失，这表明vgsc突变在台湾地区的埃及伊蚊当地种群中固定下来。五种与抗性相关的基因型，SVTCD/SVTCD、SGTFY/PGTFD、SVTCD/SGTFY、PGTFD/PGTFD和SVTCD/PGTFD，频率增加，占野外总种群的76%。我们还检测到抗性基因型SVICD/PGTFD，其频率在2016年至2023年期间在野外增加了13倍。此外，我们还观察到突变在地理上存在差异，S989P主要在高雄发现，V1016G在高雄和屏东发现。T1520I的频率在高雄明显更高，D1763Y主要发生在台南。
结论/意义：台湾地区突变的出现和扩散以及野生型蚊子的消失凸显了抗性的威胁以及台湾地区乃至全球蚊虫控制的困难。本研究确定了台湾地区埃及伊蚊的杀虫剂抗性状况，研究结果将有助于在使用拟除虫菊酯控制埃及伊蚊的地区进行抗性监测。
