RESUMEN
Resistance to insecticides is one of the great challenges that vector control programs must face. The constant use of pyrethroid-type insecticides worldwide has caused selection pressure in populations of the Aedes aegypti vector, which has promoted the emergence of resistant populations. The resistance mechanism to pyrethroid insecticides most studied to date is target-site mutations that desensitize the voltage-gated sodium channel (VGSC) of the insect to the action of pyrethroids. In the present study, susceptibility to the pyrethroid insecticides permethrin, lambda-cyhalothrin, and deltamethrin was evaluated in fourteen populations from the department of Córdoba, Colombia. The CDC bottle bioassay and WHO tube methods were used. Additionally, the frequencies of the F1534C, V1016I, and V410L mutations were determined, and the association of resistance with the tri-locus haplotypes was examined. The results varied between the two techniques used, with resistance to permethrin observed in thirteen of the fourteen populations, resistance to lambda-cyhalothrin in two populations, and susceptibility to deltamethrin in all the populations under study with the CDC method. In contrast, the WHO method showed resistance to the three insecticides evaluated in all populations. The frequencies of the mutated alleles ranged from 0.05-0.43 for 1016I, 0.94-1.0 for 1534C, and 0.01-0.59 for 410L. The triple homozygous mutant CIL haplotype was associated with resistance to all three pyrethroids evaluated with the WHO bioassay, while with the CDC bioassay, it was only associated with resistance to permethrin. This study highlights the importance of implementing systematic monitoring of kdr mutations, allowing resistance management strategies to be dynamically adjusted to achieve effective control of Aedes aegypti.
Asunto(s)
Aedes , Resistencia a los Insecticidas , Insecticidas , Mutación , Nitrilos , Piretrinas , Aedes/genética , Aedes/efectos de los fármacos , Animales , Piretrinas/farmacología , Colombia , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Nitrilos/farmacología , Permetrina/farmacología , Canales de Sodio Activados por Voltaje/genética , Mosquitos Vectores/genética , Mosquitos Vectores/efectos de los fármacos , HaplotiposRESUMEN
Aedes albopictus is considered a potential vector of arboviruses in Colombia. Females and males naturally infected with dengue, Zika and chikungunya viruses have already been found in this country. We document the first record of Ae. albopictus in the Cordoba department, in North of Colombia. The finding was carried out during Ae. aegypti collection activities in the Ayapel, Montelibano, Planeta Rica, Pueblo Nuevo and Puerto Libertador municipalities. The entomological material was collected in water containers such as cement water tanks, tanks, bottles, tires, abandoned toilets, and plastic lids with natural water located in the intradomicile, peridomicile, and extra-domicile spaces of the homes. We collected 658 Ae. albopictus samples in the larva and pupa stages, and once these reached adulthood, we determined that 389 were female and 269 were male. This is the first record of the presence of Ae. albopictus in the Cordoba department.
Asunto(s)
Aedes , Infección por el Virus Zika , Virus Zika , Femenino , Masculino , Animales , Colombia , Mosquitos Vectores , Larva , AguaRESUMEN
ABSTRACT Aedes albopictus is considered a potential vector of arboviruses in Colombia. Females and males naturally infected with dengue, Zika and chikungunya viruses have already been found in this country. We document the first record of Ae. albopictus in the Cordoba department, in North of Colombia. The finding was carried out during Ae. aegypti collection activities in the Ayapel, Montelibano, Planeta Rica, Pueblo Nuevo and Puerto Libertador municipalities. The entomological material was collected in water containers such as cement water tanks, tanks, bottles, tires, abandoned toilets, and plastic lids with natural water located in the intradomicile, peridomicile, and extra-domicile spaces of the homes. We collected 658 Ae. albopictus samples in the larva and pupa stages, and once these reached adulthood, we determined that 389 were female and 269 were male. This is the first record of the presence of Ae. albopictus in the Cordoba department.
RESUMEN
INTRODUCTION: In this study, we aimed to identify DENV-2 subtypes in Aedes aegypti pools collected between 2011 and 2017 in a rural area of Northern Cordoba, Colombia ("La Balsa"). METHODS: RT-PCR was performed to analyze the capsid/pre-membrane region (C-PrM). Sequencing and phylogenetic bayesian inference using reference DENV-2 sequences were performed. RESULTS: Twelve pools that tested positive for DENV-2 were characterized based on the C-PrM region and grouped under the Asian/American clade. CONCLUSIONS: This study is the first to report the DENV-2 Asian-American subtype in a rural area of Cordoba region, which is associated with severe dengue and local epidemics.
Asunto(s)
Aedes/virología , Virus del Dengue/clasificación , Virus del Dengue/genética , Dengue/virología , Mosquitos Vectores/virología , Filogenia , Animales , Teorema de Bayes , Colombia/epidemiología , Dengue/epidemiología , Virus del Dengue/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Serogrupo , Serotipificación , Dengue GraveRESUMEN
Abstract INTRODUCTION: In this study, we aimed to identify DENV-2 subtypes in Aedes aegypti pools collected between 2011 and 2017 in a rural area of Northern Cordoba, Colombia ("La Balsa"). METHODS: RT-PCR was performed to analyze the capsid/pre-membrane region (C-PrM). Sequencing and phylogenetic bayesian inference using reference DENV-2 sequences were performed. RESULTS: Twelve pools that tested positive for DENV-2 were characterized based on the C-PrM region and grouped under the Asian/American clade. CONCLUSIONS: This study is the first to report the DENV-2 Asian-American subtype in a rural area of Cordoba region, which is associated with severe dengue and local epidemics.