Metagenomic sequencing reveals viral diversity of mosquitoes from Egypt: co-circulation of multiple insect-specific viruses.

Mosquito-borne virus surveillance is pivotal for investigating mosquito viromes, facilitating understanding of viral evolutionary histories and genetic diversity. Natural viral communities in mosquitoes include not only insect-specific viruses (ISVs) but also viruses infecting symbiotic microorganisms. In this study, a total of 654 mosquito samples-encompassing species from the IMPORTANCE: Mosquito-borne viruses are estimated to cause over 100 million human infections annually, making surveillance of these pathogens increasingly crucial amid growing international travel and trade. Egypt, situated in northeastern Africa, serves as a geopolitical and geographical hub connecting Asia, Europe, and Africa-a unique location that complicates the surveillance of mosquito-borne viruses. Arboviruses persist in nature through cyclical transmission between arthropod vectors (e.g., mosquitoes, ticks, and midges) and susceptible vertebrate hosts. Despite this, systematic investigations into mosquito viromes remain relatively scarce in Egypt. The present study aimed to explore the genetic diversity and evolutionary relationships of mosquito-associated viruses in Egypt using metaviromic sequencing. Our findings significantly expand the current knowledge of both known and previously uncharacterized mosquito-associated viruses in the region, while also providing complete genome sequences of several viruses that may infect arthropods or vertebrates, and potentially interfere with the replication of pathogenic arboviruses.