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Epstein-Barr Virus (EBV)

Epstein-Barr virus is the germ that causes mononucleosis, or mono. You might hear mono called the “kissing disease.” This is because it often spreads through saliva (spit). Doctors and nurses sometimes call it EBV.

Most people get EBV when they are children. The virus lives inside them but does not make them sick. Cancer, cancer treatment, and other diseases can weaken the immune system. If your child has a weak immune system, EBV can cause serious illness.

Symptoms of EBV

EBV often causes no symptoms in babies and young children. If your child gets a rash while taking an antibiotic called ampicillin, it could mean that EBV is present.

Symptoms of mono include:

  • Fever
  • Sore throat
  • Swollen glands, mostly in the neck
  • Feeling very tired

Your child’s liver and spleen might be larger than normal. A doctor or nurse can check for this.

When EBV causes serious illness

If your child has cancer, sickle cell disease, or another serious illness, their immune system might be weaker than normal. When the immune system is weak, EBV can be serious. It can cause heart, lung, brain, bone marrow, and blood problems. EBV can also cause cancer in some people.

How EBV spreads

EBV spreads from one person to another, usually through saliva. A person who has mono can spread it by:

  • Kissing someone
  • Sharing eating tools such as spoons, forks, or plates
  • Drinking out of the same glass, can, or bottle
  • Sharing a toothbrush

A child with a weak immune system should not share eating or drinking items or toothbrushes. If you don't know if your child’s immune system is weak, ask the doctor or nurse.

Testing for EBV

Your child’s doctor can do a blood test to check for EBV. If EBV is present, doctors will watch for signs of illness when your child has certain treatments, such as a stem cell transplant. Your child does not need to be isolated if a blood test shows EBV is present in the blood.

To check for mono in a child with a healthy immune system, the doctor may examine your child or do a blood test.

How to keep EBV from spreading

  • Wash your hands with soap and water for at least 20 seconds. Or, use an alcohol-based hand sanitizer.
  • Wear gloves when you touch body fluids such as urine, vomit, or saliva.
  • Do not give blood if you recently had mono.

How to treat EBV

There is no specific treatment. Doctors treat EBV infection with:

  • Rest
  • Fluids such as water, juice, Gatorade, and tea
  • Medicines to treat fever or discomfort

If your child develops a serious illness because of EBV, doctors will treat that illness. For example, if your child has pneumonia or heart problems, doctors will treat those conditions.


If you have questions about EBV, mono, or your child’s immune system, talk to your care team.


  • Epstein-Barr virus (EBV) is the germ that causes mononucleosis, or mono.
  • If your child has a weak immune system, EBV can cause serious illness.
  • Proper handwashing can help stop EBV from spreading.

Reviewed: September 2022