viridae

Viridae is the formal taxonomic designation for a family of viruses within the ranking system used by the International Committee on Taxonomy of Viruses (ICTV). The suffix -viridae is appended to the name of each family, such as Herpesviridae or Poxviridae. The plural viridae is used when referring to multiple virus families. A viridae comprises one or more genera, and each genus contains one or more species. Families are grouped into higher taxonomic levels and are defined by shared characteristics, including genome type, virion morphology, replication strategy, and host range. Taxonomy is dynamic, with revisions published by the ICTV as new data become available.

Characteristics of viridae vary widely, reflecting the diversity of viruses. Members may have DNA or RNA genomes, which can be single- or double-stranded and may be linear or segmented. Virions are often enveloped or nonenveloped and can exhibit icosahedral, complex, or helical shapes. Replication can occur in the nucleus or cytoplasm, depending on the family, and host species range from humans and other animals to plants, fungi, and bacteria (via bacteriophages).

Notable examples of viridae include Herpesviridae (enveloped dsDNA viruses causing herpes infections), Poxviridae (large enveloped dsDNA viruses such as smallpox and related viruses), Retroviridae (RNA viruses with reverse transcription, including HIV), Flaviviridae (positive-sense ssRNA viruses like dengue and Zika), Coronaviridae (positive-sense ssRNA viruses including many coronaviruses), Orthomyxoviridae (negative-sense segmented RNA viruses causing influenza), and Rhabdoviridae (negative-sense RNA viruses such as rabies). These families illustrate the breadth of viral diversity organized under the viridae rank.