Mononucleosis—Child Care and Schools

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What is mononucleosis?

A disease most commonly caused by the Epstein-Barr virus (also called EBV or human herpesvirus 4) and sometimes by other viruses such as cytomegalovirus (human herpesvirus 5) and roseola (human herpesvirus 6); the illness is commonly known as mono.

What are the signs or symptoms?

  • Usually mild or no signs or symptoms, especially in young children.

  • Fever.

  • Sore throat.

  • Fatigue.

  • Swollen lymph nodes.

  • Enlarged liver and spleen.

  • Rash may occur with those treated with ampicillin or other penicillin.

What are the incubation and contagious periods?

  • Incubation period: Estimated to be 30 to 50 days for EBV.

  • Contagious period: Virus is excreted for many months after infection, and virus excretion can occur intermittently throughout life.

How is it spread?

Person-to-person contact

  • Kissing on the mouth

  • Sharing objects contaminated with saliva (eg, toys, toothbrushes, cups, bottles)

  • May be spread by blood transfusion or organ transplantation

How do you control it?

  • Hand hygiene.

  • Avoid transfer or contact with saliva (ie, through kissing or sharing respiratory secretions directly or through contact with objects like food utensils, cups, soda cans, and bottles of water).

  • People with signs and symptoms of mononucleosis should not donate blood.

What are the roles of the teacher/caregiver and the family?

  • Use good hand-hygiene technique at all the times listed in Chapter 2.

  • Clean and sanitize toys and utensils before they are shared (ie, after each child has used them).

  • Ensure all children have their own toothbrushes, cups, and eating utensils.

  • Prevent children from sharing food

  • Avoid kissing children on the mouth.

Exclude from group setting?

No, unless

  • The child is unable to participate and staff members determine they cannot care for the child without compromising their ability to care for the health and safety of the other children in the group.

  • The child meets other exclusion criteria (see Conditions Requiring Temporary Exclusion in Chapter 4).

Readmit to group setting?

Yes, when all the following criteria have been met:

  • When exclusion criteria are resolved, the child is able to participate, and staff members determine they can care for the child without compromising their ability to care for the health and safety of the other children in the group.

  • School-aged children should avoid contact sports if they have an enlarged spleen until the spleen is no longer enlarged.


  • Most people get the infection in early childhood when signs or symptoms are mild and the disease goes undiagnosed. However, rarely, the disease can be severe, particularly in adolescents.

  • General exclusion of those with mononucleosis is not practical.

Adapted from Managing Infectious Diseases in Child Care and Schools: A Quick Reference Guide.

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The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.