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What is mononucleosis?

Mononucleosis, also called "mono," is a common illness that can leave you feeling tired and weak for weeks or months. Mono goes away on its own, but lots of rest and good self-care can help you feel better.


Mono usually is caused by the Epstein-Barr virus (EBV). It is most often seen in teens and young adults. Children can get the virus, but it often goes unnoticed because of mild symptoms. Older adults usually don't get mono because they have immunity to the virus.

How is mononucleosis spread?

The virus that causes mononucleosis is found in the saliva of an infected person’s mouth.

It spreads from person to person through droplets or by contact. When someone with mononucleosis kisses, coughs, sneezes or spits, the virus can spread to other people, and people with mononucleosis may have saliva on their hands. Then, if they touch someone or something, the virus can spread.

Most people do not get sick after contact with the virus but develop antibodies to the disease. 90% of people have antibodies to the mononucleosis virus by their late teens. There is no need to keep healthy people away from someone with mononucleosis. Don’t touch the tissues, washcloths or towels that belong to someone with mononucleosis.

Children with mononucleosis may not feel well enough to go to school or the child care centre for some time, but may return when they feel well enough to participate in activities.


Usually, only self-care is needed for mono.

What to do at home

  • If another child has mononucleosis, watch your child for signs of the disease.
  • Talk to your doctor if your child has any mononucleosis signs.
  • To reduce the spread of infection, wash hands well and often, and give children their own toothbrushes, cups and eating utensils, facecloths and towels. Teach children to cover their mouths with a tissue or a sleeve (not a hand) when they sneeze or cough.