Cytomegalovirus is an infection caused by a virus. It is usually called CMV.
CMV often doesn’t cause any obvious symptoms, so you may not know you’re infected. It’s possible for an unborn child to become infected with CMV. This can cause serious problems, although it usually doesn’t. There are ways to reduce the risks.
What is CMV?
CMV is a common virus, especially in babies and young children. It's only carried by humans, not other animals.
CCMV is one of the viruses in the herpes virus family. Viruses from this family cause chickenpox, cold sores and glandular fever. All of these viruses, including CMV, can stay alive though inactive in your body for many years after you first become infected.
How do you get CMV?
CMV is transmitted from person to person through contact with body fluids, such as saliva, nasal mucous, urine, vaginal secretions, semen and breast milk.
About half of all Australian women are thought to have had CMV by the time they get pregnant.
Some women pick up CMV while pregnant. This happens through handling infected children’s toys, dirty tissues or soiled nappies. It is also possible to get CMV from having sex, a blood transfusion or an organ transplant.
Unborn babies can get CMV from their mothers while in the womb. Very occasionally, babies can get infected with CMV during breastfeeding.
How do you know if you have CMV?
CMV usually doesn't cause any noticeable symptoms. However, in some people, it can cause mild symptoms similar to those of glandular fever, such as fever, swollen glands, and a cough or cold.
CMV can cause serious illness in people who are infected with HIV or who are having chemotherapy for cancer. But most people never find out they have CMV infection, or have had it before.
Could I give CMV to my baby?
Yes. If you are pregnant and infected with CMV, your baby could be born with CMV. This is called congenital CMV.
There is a test for CMV infection. It’s recommended that pregnant women who develop symptoms of a viral infection suggestive of CMV be tested. CMV testing should be offered to women who come into frequent contact with large numbers of very young children (eg child care workers).
Even if you don't have any symptoms, you can talk to your doctor about CMV testing if you have any concerns.
How does CMV affect unborn babies?
This seems to be more likely in babies whose mothers get a new infection, rather than in mothers who have carried the virus for a long time.
Can CMV be prevented?
The best way to try to avoid getting infected with CMV is by practising good hygiene.
If you are pregnant, it is a good idea to:
- regularly and thoroughly wash your hands with soap and water, particularly when caring for children or handling anything with body fluids on it
- regularly clean surfaces and objects that may have body fluids on them
- wear gloves when changing nappies
- avoid contact with children’s saliva
- avoid sharing food, cups, utensils, or toothbrushes
There is no vaccine to prevent CMV infection.
For more information
Please see your doctor or midwife to discuss any concerns you may have. Further information is available in this CMV factsheet.
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Last reviewed: December 2019