[Infection by human herpesvirus type 6: epidemiology, immunopathology and clinical implications]

The human herpesvirus type 6 has been discovered recently and is the object of numerous investigations. Even though, its morphology is very close to the cytomegalovirus, its epidemiologic, immunopathologic and clinic characteristics are similar to the Epstein-Barr virus. Like the latter, HHV-6 persists latent in the host during all his live, frequently relapsed and is ubiquitous. Exanthema subitum in children and mononucleosis-like syndrome in adults have been attributed to acute HHV-6 infection. Under certain conditions, the development of chronic fatigue syndrome, some lymphoproliferative disorders and, perhaps, others diseases can be influenced by the persistent activity of this infection furthermore, HHV-6 can be a cofactor in infection with HIV and provokes a faster evolution and more severe illness.