Epstein Barr Virus

The Epstein-Barr virus (EBV), also called human herpesvirus 4 (HHV-4), is a cancer causing virus of the herpes family, which includes herpes simplex virus 1 and 2, and is one of the most common viruses in humans. Epstein-Barr virus occurs worldwide. It is known to cause infectious mononucleosis, is implicated in the causation of Burkitt's lymphoma and Nasopharyngeal carcinoma, and is suspected to have a role in the pathogenesis of chronic fatigue syndrome.

Most people become infected with EBV sometime during their lives, and therefore gain adaptive immunity, preventing repeated sickness from re-infection through EBV antibodies. In the United States, as many as 95% of adults between 35 and 40 years of age have been infected. Infants become susceptible to EBV as soon as maternal antibody protection disappears. Many children become infected with EBV, and these infections usually cause no symptoms or are indistinguishable from the other mild, brief illnesses of childhood. In the United States and in other developed countries, many persons are not infected with EBV in their childhood years. When infection with EBV occurs during adolescence or young adulthood, it causes infectious mononucleosis 35% to 69% of the time. In immunocompromised individuals, the Epstein-Barr virus can also present as an opportunistic infection known as hairy leukoplakia.