Infectious mononucleosis (IM, mono), also known as glandular fever, is an infection usually caused by the Epstein–Barr virus (EBV). Most people are infected by the virus as children, when the disease produces few or no symptoms. In young adults, the disease often results in fever, sore throat, enlarged lymph nodes in the neck, and tiredness. Most people recover in two to four weeks; however, feeling tired may last for months. The liver or spleen may also become swollen, and in less than one percent of cases splenic rupture may occur.While usually caused by the Epstein–Barr virus, also known as human herpesvirus 4, which is a member of the herpesvirus family, a few other viruses may also cause the disease. It is primarily spread through saliva but can rarely be spread through semen or blood. Spread may occur by objects such as drinking glasses or toothbrushes or through a cough or sneeze. Those who are infected can spread the disease weeks before symptoms develop. Mono is primarily diagnosed based on the symptoms and can be confirmed with blood tests for specific antibodies. Another typical finding is increased blood lymphocytes of which more than 10% are atypical. The monospot test is not recommended for general use due to poor accuracy.There is no vaccine for EBV, though promising vaccine research results exist. Infection can be prevented by not sharing personal items or saliva with an infected person. Mono generally improves without any specific treatment.
This may develop into systemic EBV-positive T cell lymphoma. Older adults
Infectious mononucleosis mainly affects younger adults. When older adults do catch the disease, they less often have characteristic signs and symptoms such as the sore throat and lymphadenopathy. Instead, they may primarily experience prolonged fever, fatigue, malaise and body pains. They are more likely to have liver enlargement and jaundice. People over 40 years of age are more likely to develop serious illness. (See Prognosis.) Incubation period
The exact length of time between infection and symptoms is unclear. A review of the literature made an estimate of 33–49 days. In adolescents and young adults, symptoms are thought to appear around 4–6 weeks after initial infection. Onset is often gradual, though it can be abrupt. The main symptoms may be preceded by 1–2 weeks of fatigue, feeling unwell and body aches. Cause
Epstein–Barr virus
About 90% of cases of infectious mononucleosis are caused by the Epstein–Barr virus, a member of the Herpesviridae family of DNA viruses. It is one of the most commonly found viruses throughout the world. Contrary to common belief, the Epstein–Barr virus is not highly contagious. It can only be contracted through direct contact with an infected persons saliva, such as through kissing or sharing toothbrushes. About 95% of the population has been exposed to this virus by the age of 40, but only 15–20% of teenagers and about 40% of exposed adults actually become infected. Cytomegalovirus
About 5% to 7% of cases of infectious mononucleosis is caused by human cytomegalovirus (CMV), another type of herpes virus.