Cytomegalovirus factsheet


Cytomegalovirus (CMV) is a common virus in the herpes family. It is related to other herpes viruses like:

  • herpes simplex I and II – also known as herpes, causing sores on the mouth, penis, and vulva
  • varicella-zoster virus – also known as chickenpox or shingles
  • Epstein-Barr – also known as glandular fever.

CMV can be spread through contact with:

  • fluid droplets from coughing and sneezing
  • blood
  • urine and poo
  • mucous membranes - the wet, inside lining of some body parts, like the mouth, vagina, anus, and nostrils.

Once a person has had CMV, they have the virus for the rest of their life. The virus stays inactive inside the body and can sometimes be reactivated in the future.

Babies and children are especially at risk of severe CMV symptoms if they are:

Some babies are born with CMV when the virus is passed on from their mothers during pregnancy and birth. This is called congenital CMV.

Holding and cuddling a baby who has CMV will not increase your risk of catching it.

 Signs and symptoms

CMV causes mild symptoms like a cold or flu in children who are otherwise healthy.

These can include:

  • sore throat
  • cough
  • rash
  • fever
  • swelling of the glands around the neck
  • inflammation of the liver.

More severe symptoms of CMV can affect the:

  • lungs 
  • eyes
  • brain
  • gut.

Some children will not have any symptoms.

Babies born with severe CMV are at risk of vision and hearing loss and will need regular checks as they grow.


Your local doctor can diagnose CMV based on:

  • signs and symptoms
  • a physical check
  • blood tests
  • urine tests
  • a swab of the mouth or nose.

CMV during pregnancy

Because CMV is common, it is not a standard test during pregnancy. It may be recommended during pregnancy for people who have:

  • have regular contact with young children, like childcare workers or teachers
  • symptoms of a new CMV infection
  • have another child who is attending daycare.

Babies born to mothers who develop a CMV infection during pregnancy should be screened for congenital CMV infection.

CMV in newborn babies

Newborn babies can get CMV when a mother:

  • has caught the CMV virus while pregnant
  • did not know they had CMV because they had no symptoms
  • had their previous CMV infection reactivate during pregnancy
  • breastfeeds with an active CMV virus.

Your baby’s doctor can discuss the risks and benefits of breastfeeding with a CMV infection and help you make a feeding plan.


CMV infection is usually treated by managing symptoms with:

  • rest
  • fluids
  • over the counter pain relief like ibuprofen or paracetamol for fevers.

Most children will get better on their own.

Children or babies who have severe CMV symptoms may need treatment in hospital. 


Preventing congenital CMV

Because CMV is so common, almost half of Australian women will have had the virus by the time they become pregnant. 

The only way to protect an unborn baby from getting congenital CMV is to lower the risk of catching the virus. You can lower the risk of catching CMV by:

  • not changing the nappies of other people’s babies
  • always washing your hands after caring for children, including after nappy changes and when wiping away snot and saliva
  • not kissing children on the lips
  • not sharing cups and cutlery with other people.

Preventing CMV in babies

Babies and children can spread CMV quickly as their parents and carers have constant contact with body fluids that carry a large amount of the virus. CMV can also spread quickly in places like childcare centres, where adults and children have close contact with body fluids like urine and poo.

Anyone who has not had CMV before can catch it if they touch fluids from a baby who has CMV. This can happen when you:

  • kiss a baby on the lips
  • share cups and cutlery
  • don’t wash your hands after changing a nappy.

The amount of virus in a child’s body fluids will go down as they get older.

To prevent CMV spread, practice good hygiene and teach children to do the same

Good hygiene habits include:

  • washing hands after going to the toilet
  • washing hands after touching body fluids from other people, like saliva, urine, and poo
  • not kissing children on the lips
  • not sharing cups and cutlery with other people.

Preventing CMV in babies and children

Newborn babies can get CMV when a mother:

  • catches CMV while pregnant
  • doesn't know she has CMV due to no symptoms
  • has a previous CMV infection reactivated during pregnancy
  • breastfeeds with an active CMV infection.

Your baby’s doctor can discuss the risks and benefits of breastfeeding with a CMV infection and help you make a feeding plan.

Caring for a child with CMV

If you are caring for a baby or a child with CMV, it is important to: 

  • wash your hands before and after contact with their body fluids
  • wear gloves and wash their hands before and after changing nappies. 
Last updated Wednesday 12th June 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024

This factsheet was produced with support from John Hunter Children's Hospital.