Pessoa Grasielle Caldas Dávila, dos Santos Tamara Rodrigues Martins, Salazar Gabriela Chadid, Dias Letícia Sena, de Mello Bernardino Vaz, Ferraz Marcela Lencine, Diotaiuti Liléia
Laboratório de Referência em Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, BR.
Secretaria de Saúde do Estado de Minas Gerais, Governo do Estado de Minas Gerais, Belo Horizonte, Minas Gerais, BR.
Rev Soc Bras Med Trop. 2015 Jul-Aug;48(4):417-21. doi: 10.1590/0037-8682-0047-2015.
Despite chemical and physical vector control strategies, persistent infestations of Triatoma sordida have been reported in a large part of Minas Gerais, Brazil, and the cause for this is little investigated. We aimed to characterize the deltamethrin toxicological profile in peridomestic T. sordidapopulations from Triângulo Mineiro area of Minas Gerais.
Susceptibility to deltamethrin was assessed in seventeen peridomestic T. sordida populations. Serial dilutions of deltamethrin in acetone (0.2µL) were topically applied on the first instar nymphs (F1; five days old; fasting weight, 1.2 ± 0.2mg). Dose response results were analyzed using Probit software, and the lethal doses, slope and resistance ratios were determined. Qualitative tests were also performed.
The deltamethrin susceptibility profile of T. sordida populations revealed resistance ratios ranging from 0.84 to 2.8. The percentage mortality in response to a diagnostic dose was 100.0% in all populations.
From our results, the lack of resistance to insecticides but persistent T. sordida infestations in the Triângulo Mineiro area may be because of: 1) environmental degradation facilitating dispersion of T. sordida, allowing colonization in artificial ecotopes; 2) operational failures; and 3) complexity of the peridomicile in the study area.These variables are being investigated.
尽管采取了化学和物理病媒控制策略，但巴西米纳斯吉拉斯州大部分地区仍报告有暗黑猎蝽持续侵扰，对此原因的调查较少。我们旨在描述米纳斯吉拉斯州三角矿区周边地区暗黑猎蝽种群对溴氰菊酯的毒理学特征。
对17个周边地区的暗黑猎蝽种群进行了溴氰菊酯敏感性评估。将溴氰菊酯在丙酮（0.2µL）中进行系列稀释后，局部涂抹于一龄若虫（F1；5日龄；禁食体重，1.2±0.2mg）上。使用概率软件分析剂量反应结果，并确定致死剂量、斜率和抗性比率。还进行了定性试验。
暗黑猎蝽种群对溴氰菊酯的敏感性特征显示抗性比率在0.84至2.8之间。所有种群对诊断剂量的死亡率百分比均为100.0%。
根据我们的结果，三角矿区对杀虫剂缺乏抗性但暗黑猎蝽持续侵扰可能是由于：1）环境退化促进了暗黑猎蝽的扩散，使其能够在人工生态位中定殖；2）操作失误；3）研究区域周边环境的复杂性。这些变量正在调查中。
