human herpesvirus 8
Definition: a linear double-stranded DNA virus that induces Kaposi sarcoma (KS) in immunodeficient people. DNA sequences unique to this virus are regularly found in KS specimens from HIV-negative people as well. The virus is also associated with several uncommon lymphoproliferative syndromes in AIDS patients, including multicentric Castleman disease and primary effusion lymphoma (body cavity–based lymphoma). Limited studies suggest that it sometimes causes a self-limited febrile exanthem in immunocompetent children.