Herpesvirus infection: an overview of the clinical manifestations

Herpesviruses include seven human viruses and numerous animal viruses. The human herpesviruses, in addition to their trivial names, are named from 1 to 7. The two most recently discovered herpesviruses thus being Human herpesvirus 6 and 7. Human herpesvirus 6 is the aetiologic agent causing exanthema subitum. Human herpesvirus 7 has, as yet, not been associated with any disease. A characteristic feature of the herpesviruses is the persistence in a latent form after primary infection which may later cause reactivated infection resulting in considerable morbidity, for example, in genital herpes. The clinical spectrum of herpes infections is very broad. In general, the primary infection is more severe than the reactivated. Other important determinants of morbidity are the patients' age and immune status. Many severe herpes infections are almost exclusively seen in immunocompromised patients. This review deals with the clinical manifestations of herpetic infections in normal and immunocompromised hosts with emphasis on the clinical recognition.