text: 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, often through kissing, or by sharing a drinking glass, eating utensil or needle. The disease is far less contagious than is commonly thought. Since the causative virus is also found in the mucous of the infected person, it can also spread through coughing or sneezing.\n\nA person can be infected with the virus for weeks or months before any symptoms begin to appear. Symptoms usually begin to appear 4-7 weeks after infection and may resemble strep throat or other bacterial or viral respiratory infections. These first signs of the disease are commonly confused with cold and flu symptoms. The typical symptoms and signs of mononucleosis are:\n\nFever - this varies from mild to severe, but is seen in nearly all cases. \nEnlarged and tender lymph nodes - particularly the posterior cervical lymph nodes, on both sides of the neck. \nSore throat (throat infection) - nearly all patients with EBV-mononucleosis have symptoms similar to tonsillitis. \nFatigue (sometimes extreme fatigue) \nSome patients may also display:\n\nEnlarged spleen (splenomegaly) or liver (hepatomegaly), which may later rupture \nAbdominal pain \nAching muscles \nHeadache \nLoss of appetite \nJaundice \nSinus infection \nDepression \nWeakness \nSkin rash \nAfter an initial prodrome of 1-2 weeks, the fatigue of mono often lasts from 1-2 months. The virus can remain dormant in the B cells indefinitely after symptoms have disappeared, and resurface at a later date. Many people exposed to the Epstein-Barr virus do not show symptoms of the disease, but carry the virus and can transmit it to others. This is especially true in children, in whom infection seldom causes more than a very mild illness which often goes undiagnosed. This feature, along with mono's long incubation period, makes epidemiological control of the disease impractical. About 6% of people who have had mono will relapse.