infectious mononucleosis

Last reviewed 01/2021

Infectious mononucleosis (or glandular fever) is usually a self-limiting disease caused generally by the Epstein-Barr virus (EBV), a member of the herpes virus family. The virus replicates mainly in B – lymphocytes and in some instances in the epithelial cells of the pharynx and parotid duct (1).

The virus is seen throughout the world and most people are infected by EBV at some point in their lives (2)

  • in developed countries it is commonly seen between the ages of 15 and 25 years, and presents as infectious mononucleosis
  • infection in children under 3 years is common in developing countries and is usually subclinical.
  • infants becomes susceptible to EBV when maternal antibody protection present at birth disappears (2).

The virus is excreted for some months in nasopharyngeal secretions (primarily by saliva) which are responsible for person-to-person transmission. (1)

  • many asymptomatic carriers may spread the virus intermittently through out their life (2)
  • it is often called the kissing disease since kissing can spread the virus (3)
  • it may also be spread by coughing, sneezing, or sharing a glass or food utensil
  • chewing contaminated toys may cause infections in children (4)

The possibility of developing IM after acute EBV infection appears to increase with age

  • in children - it is less than 10%
  • adolescents and young adults – between 20% - 70% (5)

It is not as contagious as common cold. Although a self-limiting disease, the virus remains in the body for life (3).

A GP with 10,000 patients can expect around seven new cases of infectious mononucleosis per year (although this number will increase in practices with a high number of young people) (6).