Detection of Dengue and Chikungunya Viruses in Mosquitoes from Nepal.

The dengue virus (DENV) and chikungunya virus (CHIKV) infection present with similar symptoms and are transmitted by Aedes mosquitoes. Until now, there have been no reported cases of DENV and CHIKV being detected in mosquitoes in Nepal. This study identified circulating arboviruses from mosquitoes collected in the capital city Kathmandu, and Dhading, Bhaktapur, and Lalitpur districts of Central Nepal in 2023. Of 105 Aedes pooled samples, 16 (15.2%) were positive for DENV, and six (5.7%) were positive for CHIKV by quantitative real-time polymerase chain reaction. DENV-2 was the most common serotype (11.4%), aligning with recent outbreaks in Nepal in 2023, followed by DENV-3 and DENV-4 (1.9% each). To the best of our knowledge, our study is the first report to detect DENV and CHIKV in Aedes mosquitoes circulating in Nepal. This study highlights the need for mosquito surveillance to prevent future outbreaks of mosquito-borne diseases in Nepal.