Serotypes of Dengue Virus andKdrMutations (F1534C, S989P, V410L, V1016I,andV1016G) inAedes aegyptiandAedes albopictusMosquitoes from the commune of Abomey-Calavi, Southern Benin

Dengue is a viral infection transmitted by mosquitoes of theAedesgenus, responsible for millions of cases each year. In Benin, several outbreaks have been reported, particularly in Abomey-Calavi, where the first dengue-related death was recorded in 2019. In the absence of a specific treatment, vector control remains the primary preventive measure. However, the emergence of insecticide resistance, notably throughkdrmutations, could compromise its effectiveness.

This study aims to identify the dengue virus serotypes circulating in the commune of Abomey-Calavi and to assess the frequency ofkdrmutationsV410L, V1016G, V1016I, F1534C, and S989PinAedes aegyptiandAedes albopictusmosquitoes. Mosquitoes were collected in August 2024 from four arrondissement Togba, Calavi, Akassato, and Godomey through morning and afternoon spraying. After morphological identification, molecular analyses were conducted to detect the viral serotypes andkdrmutations.

A total of 218Aedesmosquitoes were collected, with a predominance ofAedes aegypti(68.8%) compared toAedes albopictus(31.2%). The overall dengue positivity rate was 23.39% (95% CI: 17.9 - 29.6). The most frequent serotype was DENV-3 (12.4%), followed by DENV-2 (6.9%), DENV-1 (5%), and DENV-4 (0.09%). Six mosquitoes were co-infected with two serotypes, including three with DENV-1 and DENV-4.kdrmutations were detected in both species, with frequencies of 45% forV1016G,44% forS989P,40% forF1534C, 22% forV410L, and 19% forV1016I.Four mosquitoes carried three simultaneous mutations, while twenty-two carried two. Two mosquitoes co-infected with two serotypes also carried two different mutations. These results highlight the active circulation of the dengue virus and the presence ofkdrmutations inAedesmosquitoes in Abomey-Calavi. However, no significant association was observed between dengue infection andkdrmutations, and their distribution was independent of the viral serotype. These findings emphasize the need for regular monitoring ofkdrmutations to adapt vector control strategies and limit the spread of dengue.