Wikipedia Reference Information
Infectious mononucleosis, (also known as the kissing disease, or Pfeiffer's disease, in North America as mono, 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, muscle soreness, and fatigue. White patches on the tonsils or in the back of the throat may also be seen, (resembling strep throat). Mononucleosis is usually caused by the Epstein-Barr virus (EBV), which infects B cells (B-lymphocytes), producing a reactive lymphocytosis and atypical T cells (T-lymphocytes) known as Downey bodies.
The virus is typically transmitted from asymptomatic individuals through blood or saliva (hence "the kissing disease"), or by sharing a drink, or sharing eating utensils. The disease is far less contagious than is commonly thought. In rare cases a person may have a high resistance to infection. 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. With infectious mononucleosis, this can rise to 50-70%. Also, the total white blood count may increase to 10000-20000 per cubic millimeter.
The complete, up-to-date and editable article about Mono can be found at Wikipedia: Mono