Reoviridae is a family of viruses that can affect the gastrointestinal system (such as Rotavirus) and respiratory tract. These viruses have genomes consisting of segmented, double-stranded RNA. The name is derived from respiratory enteric orphan viruses. Orphan virus means that a virus that is not associated with any known disease.

Reovirus infection occurs often in humans, but cases are generally mild or sub-clinical. The virus can be detected in feces, and also in pharyngeal or nasal secretions, urine, cerebrospinal fluid, and blood. Some of the virus infects plants.

There are fifteen genera of Reoviridae that exist and they are divided based on the presence of a “turret” protein on the inner capsid. Reovirus have been demonstrated to have oncolytic properties and have encouraged the development of reovirus based therapies for cancer treatment.