Orphan virus
An Orphan virus is a virus that is not associated with a disease but may possess pathogenicity.
Some Orphan Viruses include Adeno-Associated Virus (Parvoviridae), Human herpesvirus 7 (Herpesviridae), Human foamy virus (Retroviridae), Human Reovirus (Reoviridae), Hepatitis G (Flaviviridae), and TT Virus (Circoviridae).