Flavivirus

**Definition:** Flaviviridae is a family of small enveloped viruses with positive-sense RNA genomes of approximately 9.0–13 kb. Most infect mammals and birds, and many are host-specific and pathogenic, such as hepatitis C virus (HCV) in the genus Hepacivirus. Most members of the genus Orthoflavivirus are arthropod-borne, and many are important human and veterinary pathogens (e.g., yellow fever virus, dengue virus, West Nile virus)