Mononucleosis

Mononucleosis, also known as “mono” is a disease most commonly caused by the Epstein-Barr virus (EBV or human herpesvirus 4). It can sometimes be caused by other viruses such as cytomegalovirus (human herpesvirus 5) or roseola (human herpesvirus 6).

How it Spreads

  • From person-to-person contact through kissing on the mouth or sharing objects contaminated with saliva (e.g., toys, toothbrushes, cups, or bottles).
  • Possibly by blood transfusion or organ transplantation.

Signs and Symptoms

  • Usually mild or no signs or symptoms, especially in young children
  • Fever, sore throat, or fatigue
  • Swollen lymph nodes
  • Enlarged liver and spleen
  • Rash may occur with those treated with amoxicillin or other penicillin

Prevention

  • Wash hands often for at least 15 to 20 seconds
  • Avoid transfer or contact with saliva through kissing or sharing respiratory secretions (coughs or sneezes) directly or through contact with objects like food utensils, cups, bottles, or drink cans).
  • People with signs and symptoms of mononucleosis should not donate blood
  • Clean and sanitize toys and utensils before they are shared (i.e., after each child has used them)
  • Ensure all children have their own toothbrushes, cups, and eating utensils
  • Prevent children form sharing food
  • Avoid kissing children on the mouth

Treatment

  • Most people get better in 2 to 4 weeks. You can help relieve symptoms by drinking fluids to stay hydrated, getting plenty of rest, taking over-the-counter medications for pain and fever
  • See your healthcare provider if you have any questions or concerns about treatment options.

Individual cases are not reportable to the Health Unit.

No exclusion necessary, unless too ill to participate in activities or has a fever with behavioural change.

Follow the direction of your healthcare provider or occupational health at your workplace.

Note: Exclusion guidelines may differ for healthcare workers.

Shope, Timothy R., Hashikawa, Andrew N. (2023). Managing Infectious Diseases in Child Care and Schools - A Quick Reference Guide (6th ed.). American Academy of Pediatrics.

U.S. Centres for Disease Control and Prevention. (2024). About Infectious Mononucleosis (Mono). Retrieved from: https://www.cdc.gov/epstein-barr/about/mononucleosis.html#:~:text=Key%20points,fatigued%20for%20several%20more%20weeks.

Contact our Communicable Disease Control (CDC) program at 705-474-1400 or toll free at 1-800-563-2808, ext. 5229, or by email to cdc@healthunit.ca for more information.

Last reviewed: May 2025, by CDC

Contact Us

North Bay Parry Sound District Health Unit

North Bay
345 Oak Street West

Parry Sound
90 Bowes St, 2nd Floor, Suite 201

Phone 705-474-1400
Toll Free 1-800-563-2808
contact@healthunit.ca