Cytomegalovirus factsheet


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

  • herpes simplex I and II – which causes sores on the mouth, penis, and vulva
  • varicella-zoster virus – which causes chickenpox
  • Epstein-Barr – which causes glandular fever.

CMV can be spread through contact with:

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

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 with suppressed immunity, like in cancer treatment or HIV, are especially at risk of severe CMV symptoms.

 Signs and symptoms

CMV causes mild symptoms like a cold or flu in generally healthy children.

Common symptoms include:

  • sore throat and cough
  • rash
  • fever
  • swelling of the glands around the neck
  • inflammation of the liver, also known as hepatitis.

Some children will not have any symptoms.

More severe symptoms of CMV can affect the:

  • lungs 
  • eyes
  • brain
  • gut.

Most babies with congenital CMV are born without problems, and most will not have any symptoms throughout their life.

Some babies born with severe CMV infections are at risk of hearing loss. Your baby will have their hearing checked at birth, and you should continue checking it as they grow.


Your child’s doctor will make a diagnosis based on their signs and symptoms, a physical examination, and tests, which may include a:


CMV infection does not usually need to be treated other than managing symptoms. Most children will get better on their own.

Children or babies who have severe CMV may need treatment in hospital. Your child’s doctor will give you more information about treatment depending on your child’s case.


How CMV is spread

CMV can be spread through:

  • fluid droplets from coughing
  • contact with blood
  • contact with wee and poo
  • contact with the wet, inside lining of some body parts, like the mouth, vagina, anus, and nostrils - also known as mucous membranes.

Babies who are born with CMV have often caught it from their mothers during pregnancy.

This can happen when a mother:

  • caught the CMV virus while pregnant
  • not known they had CMV because they had no symptoms
  • have had their previous CMV infection reactivate during pregnancy.

Newborn babies can spread the virus quickly as their parents and carers have constant contact with saliva, urine, and poo, which carries a large amount of the virus. The amount of virus in their body fluids will go down as they get older.

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

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

Babies are also at risk of CMV infection spread through breastmilk if their mother has ever had the infection. This can be severe in babies who are born very early.

Your baby’s doctor will be able to talk to you about the risks and benefits of breastfeeding with a CMV infection and will help you make a feeding plan.

Preventing congenital CMV

About half of all Australian women have had CMV by the time they are pregnant. The virus can be caught for the first time or be reactivated randomly during pregnancy.

The only way to prevent an unborn baby from getting congenital CMV is to prevent the mother from catching the virus if they have never had it before.

You can lower the risk of catching CMV during pregnancy 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 and children

The best way to avoid the spread of CMV is to have good hygiene habits and teach them to your children.

CMV can spread quickly in places like daycare because children and their body fluids are in close contact.

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.

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. 

It is important to have everyone caring for your baby wear gloves and wash their hands before and after changing nappies.

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

Last updated Wednesday 29th November 2023


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