mononucleosis virus

Infectious mononucleosis (also known in North America as mono, the kissing disease or Pfeiffer's disease, and more commonly known as glandular fever in other English-speaking countries) is a disease seen most commonly in adolescents and young adults, characterized by fever, sore throat and fatigue. It is caused by the Epstein-Barr virus (EBV) or the cytomegalovirus (CMV). It is typically transmitted from asymptomatic individuals through saliva or blood, or by sharing a drinking glass, eating utensils, or needles. The disease is far less contagious than is commonly thought. Since the causative virus is also found in the mucus of the infected person, it could be contracted in the—albeit, highly unlikely—circumstance of ingesting droplets from a carrier's cough or sneeze. The label is only partly true.

It is estimated that 90% to 95% of adults in the world have EBV-antibodies, having been infected with the Epstein-Barr virus at some point in their lives. The vast majority of infections do not result in the development of mononucleosis. The virus infects B cells (B-lymphocytes), producing a reactive lymphocytosis and the atypical T cells (T-lymphocytes). Early childhood infections often cause no symptoms. In developed countries with less crowded conditions and better hygiene, children do not commonly become infected until adolescence. Disease information, diagnosis, tests, and treatment for this member of the herpesvirus family. Since they also typically begin dating at that age, the co-occurrence of mono and kissing have led to its being called the "kissing disease," although this is but one of its modes of transmission.

The disease is so-named because the count of mononuclear leukocytes (white blood cells with a one-lobed nucleus) rises significantly. There are two main types of mononuclear leukocytes: monocytes and lymphocytes. They normally account for about 35% of all white blood cells.