Susceptibility to Insecticides and Natural Infection in Aedes aegypti: An Initiative to Improve the Mosquito Control Actions in Boyacá, Colombia

Abstract

Background: Integrated management strategies for dengue prevention and control have been the main way to decrease the transmission of arboviruses transmitted by A. aegypti in Colombia. However, the increase of chikungunya (CHIKV), Zika, and dengue (DENV) fever cases suggests deficiencies in vector control strategies in some regions from this country. Objective: This work aimed to establish a baseline susceptibility profile of A. aegypti to insecticides, determine the presence of kdr mutations associated with resistance to pyrethroids, and detect natural arbovirus infection in this vector from Moniquirá-Boyacá, one of the most endemic cities in Colombia. Methods: Mosquitos were collected in six neighborhoods, and colonies established in the laboratory. Susceptibility to malathion and lambda-cyhalothrin insecticides was evaluated, and we examined the point mutations present in portions of domains I, II, III, and IV of the sodium channel gene using a simple allele-specific PCR-based assay (AS-PCR). Findings: A. aegypti from Moniquirá showed decreased susceptibility to pyrethroid insecticides, and kdr mutations 419L, 1016I, and 1558C with allelic frequencies of 0.39, 0.40 and 0.95, respectively, were observed. The minimal infection rate (MIR) to DENV-1 was 44.1, while to CHIKV was 14.7. Conclusions: We establish a baseline insecticide resistance, kdr mutations, and arbovirus circulation, which contain the elements necessary for the consolidation of a local surveillance strategy with an early warning system and rational selection and rotation of insecticides.

Climatic and socio-economic factors supporting the co-circulation of dengue, Zika and chikungunya in three different ecosystems in Colombia

“…In addition to having differing climatic and socioeconomic profiles the three locations selected as our study domain-Bello, Cu ´cuta and Moniquira ´have contrasting levels of Ae. aegypti circulation [35][36][37][38]. There is also a higher prevalence of insecticide resistance in Ae.…”

Vector competence of lambda-cyhalothrin resistant Aedes aegypti strains for dengue-2, Zika and chikungunya viruses in Colombia

“…In the country, the continuous use of organophosphates and pyrethroids started in the 1970s and 1990s, respectively, leading to an increase in selection pressure that has contributed to the widespread of Ae. aegypti resistant populations in Colombia [19,21,[23][24][25].…”

“…Between 2006 and 2019, ten studies on lambda-cyhalothrin resistance for 126 Ae. aegypti populations were carried out in Colombia showing that 76% of the mosquito populations were resistant to this pyrethroid [19][20][21]23,25,26,[28][29][30][31]. Lambda-cyhalothrin resistance in Colombia, for Ae.…”

“…Lambda-cyhalothrin resistance in Colombia, for Ae. aegypti is associated with the presence of the V1016I and F1534C kdr mutations, but metabolic detoxification mechanisms also have been reported [20,21,25,[31][32][33][34][35][36][37]. In addition, a significant correlation has been observed between the frequency I1016 genotype and 50% lethal concentration for lambda-cyhalothrin [36].…”