Human herpesvirus-6.

Human herpesvirus-6 (HHV-6), a mature T-cell lymphotropic virus, is a newly recognized member of the herpes virus family and shares limited homology with human cytomegalovirus. HHV-6 has been identified as the etiologic agent of the childhood illness exanthem subitum (roseola infantum). Widespread acquisition of this virus has been demonstrated to occur early in childhood, with fever as the most consistent manifestation of primary infection. Reactivation of latent infection has been postulated and may be associated with lymphoproliferative disorders or other diseases of immune function.