Researchers from the GHTM | IHMT NOVA have recently published a study in the journal Parasites & Vectors reporting on pyrethroid resistance in Aedes albopictus, a key vector of arboviral diseases in Europe. The study, entitled “Tracking pyrethroid resistance in arbovirus mosquito vectors: mutations I1532T and F1534C in Aedes albopictus across Europe”, was conducted by Vera Valadas and João Pinto of the VBD-GHTM Research Group, and provides important insights into the geographic distribution of resistance-associated mutations and their implications for vector control strategies across the continent.
Pyrethroid Resistance: A Growing Public Health Challenge
Aedes albopictus, commonly known as the Asian tiger mosquito, is a rapidly spreading invasive species and a competent vector for dengue, chikungunya, and Zika viruses. In Europe, pyrethroids remain a primary tool for emergency mosquito control, but the emergence of resistance threatens their effectiveness. Understanding the genetic mechanisms underlying resistance is critical to maintaining effective vector control and protecting public health.
The study aimed to assess the prevalence and distribution of two knockdown resistance (kdr) mutations — I1532T and F1534C — in European populations of Aedes albopictus. These mutations affect the voltage-gated sodium channel and are associated with reduced susceptibility to pyrethroid insecticides. Samples from multiple sites across the continent were genotyped to determine the presence, frequency, and geographic patterns of these resistance markers.
Key Findings: Resistance Mutations Across Europe
Analysis of 1,732 mosquito specimens from 54 sites across 19 countries revealed that the F1534C mutation was widespread, being detected in 78 specimens overall across nine sites in six countries, particularly in Cyprus (n=53) and Greece (n=47), while the I1532T mutation was present at lower frequencies, detected in 26 specimens from 11 sites in seven countries, including Albania, France, Greece, Italy, Romania, Spain, and Turkey.
These results indicate that resistance-associated alleles are establishing across Europe, likely driven by selective pressure from insecticide use. The findings highlight the urgent need for systematic monitoring of pyrethroid resistance within integrated vector management programs. Reliance on pyrethroids alone may no longer be sufficient, and adaptive strategies incorporating molecular surveillance can inform timely interventions and mitigate the spread of resistant mosquito populations.
Geographic differences in mutation frequencies, particularly in the Eastern Mediterranean region, emphasize priority areas for targeted surveillance and control measures.
This study provides the first comprehensive map of major kdr alleles in Aedes albopictus across Europe, offering a baseline for ongoing surveillance. The authors conclude that continuous monitoring of resistance markers is essential to preserve the efficacy of existing control tools and guide adaptive vector management strategies in response to the expanding arboviral threat.
Advancing Vector-Borne Disease Research with GHTM
This study resulted from an extensive national and international collaboration, involving entomologists and public health partners across 19 European countries, including Albania, Cyprus, France, Georgia, Greece, Italy, Romania, Spain, and Turkey, among others. The collaborative effort included coordinated field sampling, laboratory analysis, and data interpretation, supported by research frameworks such as the ARBOMONITOR project and the AIM-COST Action on invasive Aedes mosquitoes.
The publication demonstrates the collaborative efforts of GHTM researchers and international partners to strengthen understanding of insecticide resistance in mosquito vectors, reinforcing GHTM’s commitment to research on vector biology, resistance surveillance, and arbovirus preparedness.
The full article is available on the Parasites & Vectors website:
Tracking pyrethroid resistance in arbovirus mosquito vectors: mutations I1532T and F1534C in Aedes albopictus across Europe.