Dias Luciana Dos Santos, Martins Ademir Jesus, Rodovalho Cynara de Melo, Bellinato Diogo Fernandes, de Ázara Tatiana Mingote Ferreira, do Nascimento Aline Machado Rapello, Corbel Vincent, Macoris Maria de Lourdes da Graça, Andrighetti Maria Teresa Macoris, Lima José Bento Pereira
Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Biologia, Controle e Vigilância de Insetos Vetores, Rio de Janeiro, RJ, Brasil.
Universidade Federal do Rio de Janeiro, Instituto Nacional de Ciência em Entomologia Molecular, Rio de Janeiro, RJ, Brasil.
Mem Inst Oswaldo Cruz. 2025 Jul 11;120:e240270. doi: 10.1590/0074-02760240270. eCollection 2025.
Insecticides play a critical role in controlling insect vectors, particularly during epidemics. Effective chemical control relies on the robust monitoring of insecticide resistance to guide evidence-based decision-making in vector control strategies.
This study assessed the susceptibility of Aedes aegypti, the primary vector of dengue, Zika, and Chikungunya viruses, to various larvicides and adulticides deployed during Brazil's national campaigns from 2020 to 2023.
Mosquito collection was performed in 46 Brazilian municipalities using ovitraps. Eggs were transported to FIOCRUZ to establish the F1 and F2 generations. The Rockefeller strain was employed to determine the discriminating concentrations (DC) for the larvicide Natular™ 20EC (spinosad) and the adulticides Cielo™ (imidacloprid and prallethrin) and Fludora® Fusion (clothianidin and deltamethrin) using a modified World Health Organization (WHO) bottle bioassay. These DCs were then used to estimate the resistance status of Ae. aegypti populations in the tested formulations. Resistance intensity was assessed by exposing mosquitoes to five, 10, or 20 times the DC concentrations.
All Ae. aegypti populations were fully susceptible to larvicide spinosad. However, resistance to both adulticide formulations was detected based on WHO criteria (mortality rates < 90%). Intensity assays revealed high to very high resistance to combined adulticide products.
Our findings indicate the full susceptibility of Ae. aegypti populations in Brazil to spinosad, but substantial resistance to adulticides used in space spraying and residual applications, likely due to pre-existing pyrethroid resistance. However, the specific contributions of each active ingredient remain unclear, owing to the evaluation of the combined formulations. The efficacy of both traditional and alternative vector control strategies must be continuously evaluated and closely monitored to ensure the real-time assessment of their performance. For chemical control, future studies should prioritise the assessment of combination products in field trials, refining laboratory assays, and sustaining insecticide resistance surveillance to optimise control efforts in Brazil.
杀虫剂在控制昆虫媒介方面发挥着关键作用，尤其是在疫情期间。有效的化学防治依赖于对杀虫剂抗性的有力监测，以指导病媒控制策略中基于证据的决策。
本研究评估了埃及伊蚊（登革热、寨卡病毒和基孔肯雅病毒的主要传播媒介）对2020年至2023年巴西全国防治运动中使用的各种杀幼虫剂和杀虫剂的敏感性。
在巴西46个城市使用诱蚊产卵器收集蚊子。将卵运至奥斯瓦尔多·克鲁兹基金会以建立F1和F2代。采用改良的世界卫生组织（WHO）瓶式生物测定法，使用洛克菲勒品系来确定杀幼虫剂Natular™ 20EC（多杀菌素）以及杀虫剂Cielo™（吡虫啉和炔丙菊酯）和Fludora® Fusion（噻虫胺和溴氰菊酯）的区分浓度（DC）。然后使用这些区分浓度来估计受试制剂中埃及伊蚊种群的抗性状况。通过将蚊子暴露于区分浓度的5倍、10倍或20倍浓度下评估抗性强度。
所有埃及伊蚊种群对杀幼虫剂多杀菌素均完全敏感。然而，根据世界卫生组织标准（死亡率<90%）检测到对两种杀虫剂制剂均有抗性。强度测定显示对组合杀虫剂产品具有高至非常高的抗性。
我们的研究结果表明巴西的埃及伊蚊种群对多杀菌素完全敏感，但对空间喷洒和残留应用中使用的杀虫剂具有显著抗性，这可能归因于先前存在的拟除虫菊酯抗性。然而，由于对组合制剂的评估，每种活性成分的具体贡献仍不清楚。必须持续评估并密切监测传统和替代病媒控制策略的效果，以确保实时评估其性能。对于化学防治，未来的研究应优先在田间试验中评估组合产品、完善实验室测定方法并持续进行杀虫剂抗性监测，以优化巴西的防治工作。
