Pessoa Grasielle Caldas Dávila, Obara Marcos Takashi, Rezende João G, de Mello Bernardino Vaz, Ferraz Marcela Lencine, Diotaiuti Liléia
Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas/CPqRR/FIOCRUZ, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Av. Augusto de Lima 1715, Barro Preto, 29190-002, Belo Horizonte, MG, Brazil.
Laboratório de Entomologia, Universidade Federal de Brasília, Brasília, DF, Brazil.
Parasit Vectors. 2015 May 8;8:263. doi: 10.1186/s13071-015-0873-7.
In general, there was a large reduction in the occurrence of cases of Chagas disease in the last decades in Brazil. However, despite all of these efforts, there have been various reports of persistent reinfestations of T. sordida in a large part of the state of Minas Gerais, for reasons still little investigated. Thus, this purpose of this study was to characterize the deltamethrin susceptibility profile of peridomestic T. sordida populations from North of Minas Gerais-Brazil.
Susceptibility to deltamethrin was assessed in seventeen peridomestic populations of T. sordida from North region of Minas Gerais, Brazil. Serial dilutions of deltamethrin in acetone (0.2 μL) were topically applied in first instar nymphs (F1, five days old, fasting, weight 1.2 ± 0.2 mg). Dose response results were analyzed with POLO program, determining the lethal doses, slope and resistance ratios (RR).
Susceptibility profile characterization of T. sordida populations revealed resistance ratios (RR50) ranging from 2.50 to 7.08.
In fact, we know very little about the real impact of the resistance ratios obtained in the laboratory bioassays on the effectiveness of the vector control activities in the field. Thus, we prefer to refer to the populations with RR > 5 as populations with altered susceptibility. For these populations, the realization of laboratory and field trials, simultaneous and complementary, permitting the evaluation of both, is recommended.
总体而言，巴西在过去几十年中恰加斯病病例的发生率大幅下降。然而，尽管付出了所有这些努力，但仍有各种报告称，米纳斯吉拉斯州大部分地区存在索尔迪锥蝽的持续再感染情况，原因仍鲜为人知。因此，本研究的目的是描述巴西米纳斯吉拉斯州北部家栖索尔迪锥蝽种群对溴氰菊酯的敏感性特征。
对来自巴西米纳斯吉拉斯州北部地区的17个家栖索尔迪锥蝽种群进行了溴氰菊酯敏感性评估。将溴氰菊酯在丙酮（0.2 μL）中的系列稀释液局部施用于一龄若虫（F1，5日龄，禁食，体重1.2±0.2 mg）。用POLO程序分析剂量反应结果，确定致死剂量、斜率和抗性比率（RR）。
索尔迪锥蝽种群的敏感性特征显示抗性比率（RR50）在2.50至7.08之间。
事实上，我们对实验室生物测定中获得的抗性比率对现场病媒控制活动有效性的实际影响知之甚少。因此，我们更倾向于将RR>5的种群称为敏感性改变的种群。对于这些种群，建议同时进行实验室和现场试验，相互补充，以便对两者进行评估。
