Herpesviruses

Herpesviruses are a family of DNA viruses with extremely high prevalence rates.

Types
Viruses in this family include HSV-1 and HSV-2, Epstein-Barr virus (HHV4), which causes mononucleosis, Varicella zoster virus, which causes chickenpox and shingles. More than 90% of adults have been infected with at least one of these viruses.

Other herpesviruses include human cytomegalovirus, HHV-6, HHV-7, and Kaposi's sarcoma-associated herpesvirus.

Latency
They share in common that after the initial infection, these viruses usually remain latent for life.

Reactivation
Reactivation of these viruses have been associated with a number of diseases. HSV-1 has been implicated in Alzheimer's.

Several of these viruses have transactivating potential.

Chronic fatigue syndrome
It is unclear whether herpesviruses associated with Chronic fatigue syndrome play an etiological role or are "bystanders" – opportunistic reactivations under a state of immune dysregulation.