Chronic mononucleosis--it almost never happens.

Obviously, a great deal of further research is needed into the effects of latent viral infections. A better understanding of the interaction between psychobiologic disorders and the immune system may also shed light on many of the unanswered questions concerning the role of Epstein-Barr virus (EBV) as well as other latent viruses in clinical disease. At this time, however, there is no convincing evidence that chronic EBV infection is a cause of clinical disease, except in rare instances.