Early Pyrethroid Resistance Detected in Dengue Mosquitoes from Southern India

Aedes aegypti, the primary mosquito vector of dengue, chikungunya, and Zika viruses, is controlled largely with pyrethroid insecticides, and the emergence of resistance in mosquito populations poses a major challenge to vector control. A study published in Acta Parasitologica reports the presence of the V1016G knockdown resistance (kdr) mutation in Aedes aegypti collected from Nagapattinam district, Tamil Nadu, in southern India, together with bioassay evidence of reduced susceptibility to pyrethroids in these field populations.

The research team collected Aedes immatures from selected field sites in the district. Insecticide susceptibility was assessed following World Health Organization guidelines, and genomic DNA extracted from the samples was screened for the V1016G mutation in the voltage-gated sodium channel gene (vgsc) using allele-specific PCR.

The molecular analysis detected the V1016G mutation in heterozygous form (VG) among the tested samples, while no homozygous mutants (GG) were found. The authors interpret the presence of heterozygous individuals as indicating an early stage of resistance development, likely driven by ongoing insecticide selection pressure. The bioassay results showed reduced susceptibility to pyrethroids in these populations, a phenotypic finding consistent with the molecular data.

The study provides baseline data on the genetic mechanism of pyrethroid resistance in Aedes aegypti from Nagapattinam district. The authors emphasize that regular monitoring of kdr mutations is essential to detect resistance early and to guide insecticide use policies, and that integrating molecular surveillance with conventional control measures will help delay the spread of resistance and improve the long-term success of vector management programs. They also highlight the need for alternative control strategies and responsible insecticide use to maintain the effectiveness of current interventions. As a single-district survey, the study describes the sampled populations at a specific point in time, and the heterozygous-only genotype distribution indicates an early stage of resistance rather than an established, widespread one.

Subject of Research: Pyrethroid resistance mechanisms in the dengue vector Aedes aegypti

Article Title: Presence of Heterozygous V1016G kdr Mutation in Pyrethroid Insecticide Resistance in Aedes aegypti a Dengue vector from Southern India

Article References: Anbalagan, R., M, P., Henri, M., Kaseem, F. S., Jeevitha, S., Malik, M. R., & Krishnan, J. (2026). Presence of Heterozygous V1016G kdr Mutation in Pyrethroid Insecticide Resistance in Aedes aegypti a Dengue vector from Southern India. Acta Parasitologica, 71(6), Article 244. https://doi.org/10.1007/s11686-026-01424-9

Image Credits: AI Generated

DOI: 10.1007/s11686-026-01424-9

Keywords: Aedes aegypti, kdr mutation, V1016G, pyrethroid resistance, voltage-gated sodium channel, dengue vector, Tamil Nadu, India, allele-specific PCR, WHO susceptibility testing, vector control, insecticide resistance monitoring