Redondoviruses (members of the Redondoviridae) are a family of human-associated DNA viruses. Their name derives from the inferred circular structure of the viral genome (“redondo” means round in Spanish). Redondoviruses have been identified in DNA sequence based surveys of samples from humans, primarily samples from the oral cavity and upper airway.

Redondoviruses are assigned by the International Committee on Taxonomy of Viruses (ICTV) to the Redondoviridae.

The family Redondoviridae contains one genus, Torbevirus, which contains two species, Brisavirus (Torbevirus brisa) and Vientovirus (Torbevirus viento). The names derive from the words for breeze and wind in Spanish (“brisa” and “viento”), denoting the association with the human airway.

The redondoviruses are members of the Circular Rep-Containing Single Stranded (CRESS) DNA Virus group.

The redondovirus genome is circular, and by analogy to other CRESS viruses likely single stranded. Genomes are about 3.0 kilobases in size. The genome encodes three inferred proteins:

Redondovirus genomes have been reported primarily from human samples surveyed using metagenomic DNA sequencing. They have been found primarily in oral and airway specimens.In some human populations, oral samples can show up to 80% Redondovirus positivity.

Analysis of a variety of human-derived sample types showed a strong positive correlation of Redondovirus DNA and DNA of the oral amoeba Entamoeba gingivalis. Follow up studies showed that a xenic culture containing Entamoeba gingivalis and feeder bacteria was also positive for redondovirus DNA and RNA. Analysis using intracellular cross linking (Hi-C) showed crosslinking of redondovirus DNA to Entamoeba DNA, supporting Entamoeba gingivalis as the host.

It is unknown whether redondoviruses cause human disease. Some CRESS viruses are known pathogens, such as porcine circovirus type 2.