Honghe Bunya-like virus: a novel virus identified in mosquitoes from Yunnan, China

BACKGROUND: Arboviruses represent a persistent and escalating threat to global public health, with mosquitoes serving as the principal vectors in their natural transmission cycles and geographic dissemination. Yunnan Province, southwestern China, is a recognized hotspot for arboviral diversity, yet the full spectrum of mosquito-borne viruses circulating in this region remains incompletely characterized. RESULTS: A total of 3,300 female mosquitoes of four species across four genera were collected from rural areas of Honghe County, Yunnan Province in 2024, and subjected to viral metatranscriptomic sequencing. A previously undescribed bunya-like virus, designated Honghe Bunya-like virus, was identified in two locally dominant hematophagous mosquito species, with minimum infection rates of 0.2% and 0.3%, respectively. The viral genome comprises three single-stranded negative-sense RNA segments (L, M, and S) encoding the RdRp, glycoprotein, and nucleoprotein, respectively, consistent with the canonical architecture of the genus Orthobunyavirus. Phylogenetic analyses placed the virus within Orthobunyavirus across all three segments, though inter-segment topological incongruence was observed; amino acid identities to known orthobunyaviruses (49.7%-71.6%) fell below conspecific thresholds, suggesting a novel species. CONCLUSIONS: This study expands the known genetic diversity of mosquito-associated virus in southwestern China and, given the phylogenetic affinity to pathogenic orthobunyaviruses and the hematophagous nature of the vector species, raises the possibility of vertebrate infection potential warranting further investigation.