Centro Regional de Investigación en Salud Pública, Instituto Nacional de Salud Pública, Cuarta Norte y 19 Calle Poniente, Centro S/N, Tapachula CP 30700, Chiapas, Mexico.
Jurisdicción Sanitaria VII, Antiguo Hospital General de Tapachula, Carretera Antiguo Aeropuerto, Tapachula CP 30798, Chiapas, Mexico.
Int J Environ Res Public Health. 2023 Feb 27;20(5):4258. doi: 10.3390/ijerph20054258.
Chiapas State comprises the largest malaria foci from Mexico, and 57% of the autochthonous cases in 2021, all with infections, were reported in this State. Southern Chiapas is at constant risk of cases imported due to migratory human flow. Since chemical control of vector mosquitoes is the main entomological action implemented for the prevention and control of vector-borne diseases, this work aimed to investigate the susceptibility of to insecticides. To this end, mosquitoes were collected in cattle in two villages in southern Chiapas in July-August 2022. Two methods were used to evaluate the susceptibility: the WHO tube bioassay and the CDC bottle bioassay. For the latter, diagnostic concentrations were calculated. The enzymatic resistance mechanisms were also analyzed. CDC diagnostic concentrations were obtained; 0.7 μg/mL deltamethrin, 12 μg/mL permethrin, 14.4 μg/mL malathion, and 2 μg/mL chlorpyrifos. Mosquitoes from Cosalapa and La Victoria were susceptible to organophosphates and to bendiocarb, but resistant to pyrethroids, with mortalities between 89% and 70% (WHO), and 88% and 78% (CDC), for deltamethrin and permethrin, respectively. High esterase levels are suggested as the resistance mechanism involved in the metabolism of pyrethroids in mosquitoes from both villages. Mosquitoes from La Victoria might also involve cytochrome P. Therefore, organophosphates and carbamates are suggested to currently control . Its use might reduce the frequency of resistance genes to pyrethroids and vector abundance and may impede the transmission of malaria parasites.
恰帕斯州是墨西哥最大的疟疾疫区之一，2021 年 57%的本地疟疾病例发生在该州，所有病例均为 感染。由于人口流动，恰帕斯州南部一直存在输入性病例的风险。由于化学控制媒介蚊虫是预防和控制虫媒疾病的主要昆虫学措施，因此这项工作旨在研究 对杀虫剂的敏感性。为此，于 2022 年 7 月至 8 月在恰帕斯州南部的两个村庄采集牛身上的蚊子。使用两种方法评估敏感性：世界卫生组织管生物测定法和疾病预防控制中心瓶生物测定法。后者计算了诊断浓度。还分析了酶抗性机制。获得了疾病预防控制中心的诊断浓度；0.7μg/mL 溴氰菊酯、12μg/mL 氯菊酯、14.4μg/mL 马拉硫磷和 2μg/mL 毒死蜱。来自科萨拉帕和拉维多利亚的蚊子对有机磷化合物和苯氧威敏感，但对拟除虫菊酯具有抗性，死亡率分别为 89%和 70%（世界卫生组织）和 88%和 78%（疾病预防控制中心），分别为溴氰菊酯和氯菊酯。高酯酶水平表明，这是两种蚊子代谢拟除虫菊酯的抗性机制。拉维多利亚的蚊子可能还涉及细胞色素 P。因此，建议使用有机磷化合物和氨基甲酸酯来控制 。它的使用可能会降低对拟除虫菊酯和媒介丰度的抗性基因的频率，并可能阻碍疟原虫的传播。
