Togaviridae and Flaviviridae

Togaviridae and Flaviviridae are two similar positive-sense single-stranded enveloped RNA virus families that are characterized by a single mRNA that results in a polyprotein that is posttranslationally modified. Originally the genera Flavivirus and Pestivirus were included in the family Togaviridae but based on differences in genomic organization and glycoproteins, a new family, Flaviridae, was established in 1984 that included viruses in the genera Flavivirus and Pestivirus . The family Togaviridae includes two genera, Alphavirus and Rubivirus (which has a single member, rubella virus, the cause of human rubella [German measles]). The family Flaviviridae contains a large number of viruses within three antigenically distinct genera: Flavivirus, Pestivirus, and Hepacivirus (human hepatitis C virus). The family Flaviviridae includes a number of important human pathogens. Although Zika, a flavivirus, emerged in 2015 as an important human arbovirus, the veterinary flaviviruses have not seen any new “emerging viruses.”