Entomo-Virological Surveillance and Genomic Insights into DENV-2 Genotype III Circulation in Rural Esmeraldas,...

Area of Science:

• Medical Entomology
• Virology
• Epidemiology

Background:

• Ecuador experiences frequent dengue outbreaks, with a significant surge in cases from 2022 to 2024.
• Rural areas like Borbon in Esmeraldas province are crucial for understanding dengue transmission dynamics.

Purpose of the Study:

• To investigate the genotypes of dengue virus serotype 2 (DENV-2) circulating in a rural Ecuadorian setting.
• To integrate genomic analysis with entomological and virological surveillance for enhanced dengue monitoring.

Main Methods:

• Entomo-virological surveillance was conducted in Borbon, Esmeraldas.
• RT-qPCR was used to detect DENV serotype 2 in Aedes aegypti mosquito pools.
• Whole-genome sequencing (Illumina MiSeq) and phylogenetic analysis (Dengue Typing Tool, Maximum Likelihood) were performed for genotyping.

Main Results:

• Five pools of Aedes aegypti mosquitoes tested positive for DENV-2.
• Genomic sequencing identified the DENV-2 genotype as III Southern Asian-American.
• The sequenced genome showed genetic similarity to a 2021 DENV genome from Esmeraldas and clustered with other American DENV strains.

Conclusions:

• The study identified a specific DENV-2 genotype circulating in a rural area of Ecuador, contributing to regional dengue epidemiology.
• Findings underscore the importance of combined clinical surveillance and vector monitoring for effective dengue control strategies in endemic rural settings.