Mirusha virus: A novel sand fly-borne phlebovirus with evidence of neutralizing antibodies in humans and dogs in Kosovo

In Europe, phleboviruses are transmitted by phlebotomine sand flies, which are widely distributed in the Mediterranean basin, including the Balkan peninsula. We report the identification and isolation of Mirusha virus (MRSHV), a novel member of the Phlebovirus corfouense species within the Phenuiviridae family, based on a > 95% genetic identity at the aminoacid level for Large segment between MRSHV and Corfou virus. MRSHV was isolated from a Phlebotomus perfiliewi sand fly specimen collected in Kosovo in 2022. Whole genome sequencing of MRSHV the characteristic trisegmented genome architecture of phleboviruses. Mammalian cells, including green monkey cell lines, were susceptible to MRSHV, with limited replication in dog macrophage cells, whereas no replication was observed in mosquito cell lines, suggesting a vector-specific adaptation. Specific neutralizing antibodies were detected in dogs (2.0%) and in humans (0.8%) from various regions of Kosovo, indicating a broader geographic circulation. Our findings describe a previously uncharacterized phlebovirus and underscore the importance of considering sand fly–borne phlebovirus infections in cases of undiagnosed febrile illness during the vector-active season, as well as expanding arbovirus surveillance to include hematophagous arthropods beyond mosquitoes.