Who Is Affected by Infectious Mononucleosis

Infectious mononucleosis (mono) occurs in about 1 out of 2,000 people every year. People between the ages of 15 and 24 are most likely to have symptoms of mono. footnote 1

Most people have been exposed to Epstein-Barr virus (EBV) , which causes mono, by the time they reach adulthood. They likely won't have symptoms, but they can spread the virus to others every now and then throughout their lives.

  • Young children infected with the virus usually have no symptoms or only mild symptoms.
  • If a person is first infected with the virus as a teen or young adult, he or she is likely to develop symptoms of mono.


  1. Johannsen EC, Kaye KM (2010). Epstein-Barr virus (infectious mononucleosis, Epstein-Barr virus-associated malignant diseases, and other diseases). In GL Mandell et al., eds., Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 7th ed., vol. 2, pp. 1989–2010. Philadelphia: Churchill Livingstone Elsevier.

ByHealthwise Staff

Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine

Specialist Medical Reviewer W. David Colby IV, MSc, MD, FRCPC - Infectious Disease

Current as ofMay 22, 2015