Quaranjavirus is a new genus of enveloped RNA viruses, one of six genera in the virus family Orthomyxoviridae. The genome is single-stranded, negative-sense segmented RNA, generally with six segments. Quaranfil virus is the type species, and the genus also contains the species Johnston Atoll virus; it has been proposed to contain species or strains including Cygnet River virus, Lake Chad virus, Tyulek virus and Wellfleet Bay virus. Quaranjaviruses predominantly infect arthropods and birds; as of March 2015, Quaranfil virus is the only member of the genus to have been shown to infect humans. The Quaranfil and Johnston Atoll viruses are transmitted between vertebrates by ticks, resembling members of Thogotovirus, another genus of Orthomyxoviridae.