Cytomegalovirus (CMV)

What is CMV?
Cytomegalovirus (CMV) is a member of the Herpes virus family. CMV is a common viral infection with approximately 60% of European people being infected by adulthood. After infection, the virus remains dormant within the body but can be reactivated during periods when the body’s immune system is weakened.

Cytomegalovirus infection (congenital) is a notifiable disease.

How is CMV infection acquired?
CMV infection is transmitted from person to person via contact with infected body fluids (urine, saliva, blood, faeces, semen, breast milk, tears). CMV is also spread through sexual contact, kissing, blood transfusion, organ transplants and from an infected mother to baby during pregnancy or via breast feeding.

What are the symptoms of CMV infection?
CMV infections are usually asymptomatic in healthy individuals but can occasionally cause the following symptoms:

  • Fever
  • Fatigue
  • Sore throat
  • Swollen glands

Who is at risk of CMV disease?
CMV infections are usually asymptomatic in healthy individuals but can cause disease in newborn/premature babies and immunosuppressed individuals (such as chemotherapy patients, transplant recipients and HIV infected patients). CMV infection in immunosuppressed individuals can cause mild to severe disease such as pneumonia, retinitis (inflammation of the retina of the eye), hepatitis (inflammation of the liver), gastrointestinal disease and/or neurological manifestations.

Pregnant women who contract CMV infection during pregnancy can pass the infection on to their unborn baby who may go on to develop congenital CMV disease.

Congenital CMV disease
Each year, approximately one in 150 children in the United States and the UK is born with or develops disabilities as a result of CMV infection. However, only about one fifth of these will become unwell or develop long term problems. If a baby does develop problems, these can include:

  • Problems with liver, lung and/or spleen
  • Small size at birth
  • Small head
  • Mental disability
  • Loss of vision or hearing
  • Seizures
  • Lack of co-ordination
  • Bleeding problems

How is CMV infection treated?
Currently there is no recommended treatment for CMV infection. Use of antiviral treatment in infected babies is currently being evaluated while vaccines for the prevention of CMV infection are still under development.

Tips for preventing CMV infection:

  • Wash hands thoroughly and frequently with soap and water. This is especially important
    • after handling nappies
    • before preparing, serving or eating food
    • after going to the toilet
    • after hands have been contaminated with any bodily fluid
  • Avoid kissing children <5 years old on the mouth or cheek. Kiss them on the head or hug them instead
  • Do not share food, drinks or utensils with children <5 years old
  • Frequently and thoroughly cleanse surfaces contaminated by body fluids (urine, saliva, blood, faeces, semen, breast milk, tears)
  • Avoid kissing or intimate contact with people known to be CMV positive

Pregnant women
If you are pregnant, taking some basic precautions can reduce your risk of developing a CMV infection:

  • Wash your hands regularly using soap and hot water, particularly before preparing food, before eating, after close contact with children and after changing nappies.
  • Avoid kissing a young child on the face. Hugging a child, or kissing them on the head, presents no extra risk.
  • Do not share eating utensils (forks and spoons) with young children, or drink from the same glass as them.

These precautions are particularly important if you have a job that brings you into close contact with young children, such as working in a day care centre or nursery.

If your job involves spending a considerable amount of time with young children, you can have a blood test to find out whether you have previously been infected with CMV.

Further useful information is available on the HSE website

Last updated: 26 April 2017