Human herpesvirus 6: An emerging pathogen.
Infections with human herpesvirus 6 (HHV-6), a beta-herpesvirus of which two variant groups (A and B) are recognized, is very common, approaching 100% in seroprevalence. Primary infection with HHV-6B causes roseola infantum or exanthem subitum, a common childhood disease that resolves spontaneously. After primary infection, the virus replicates in the salivary glands and is shed in saliva, the recognized route of transmission for variant B strains; it remains latent in lymphocytes and monocytes and persists at low levels in cells and tissues. Not usually associated with disease in the immunocompetent, HHV-6 infection is a major cause of opportunistic viral infections in the immunosuppressed, typically AIDS patients and transplant recipients, in whom HHV-6 infection/reactivation may culminate in rejection of transplanted organs and death. Other opportunistic viruses, human cytomegalovirus and HHV-7, also infect or reactivate in persons at risk. Another disease whose pathogenesis may be correlated with HHV-6 is multiple sclerosis. Data in favor of and against the correlation are discussed.
Campadelli-Fiume
G
G
University of Bologna, Italy. campadel@kaiser.alma.unibo.it
Mirandola
P
P
Menotti
L
L
D000328:Adult; D002493:Central Nervous System Diseases / Q000821:virology; D002648:Child; D005077:Exanthema Subitum / Q000453:epidemiology / Q000503:physiopathology; D016679:Genome, Viral; D006566:Herpesviridae Infections / Q000453:epidemiology / Q000503:physiopathology / Q000821:virology; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000472:pathogenicity; D016199:Herpesvirus 7, Human; D006801:Humans; D009103:Multiple Sclerosis / Q000821:virology; D009894:Opportunistic Infections / Q000821:virology; D012514:Sarcoma, Kaposi / Q000821:virology