Cytomegalovirus (CMV) is a common virus. Once infected, your body retains the virus for life. Most people don't know they have cytomegalovirus (CMV) because it rarely causes problems in healthy people.

If you're pregnant or if your immune system is weakened, CMV is cause for concern. Women who develop an active CMV infection during pregnancy can pass the virus to their babies, who might then experience symptoms. For people who have weakened immune systems, especially people who have had an organ, stem cell or bone marrow transplant, CMV infection can be fatal.

CMV spreads from person to person through body fluids, such as blood, saliva, urine, semen and breast milk. There is no cure, but there are medications that can help treat the symptoms.


Most healthy people who are infected with CMV may experience no symptoms. Some experience minor symptoms. People who are more likely to experience signs and symptoms of CMV include:

  • Newborns who became infected with CMV before they were born (congenital CMV).
  • Infants who become infected during birth or shortly afterward (perinatal CMV). This group includes babies infected through breast milk.
  • People who have weakened immune systems, such as those who have had an organ, bone marrow or stem cell transplant, or those who are infected with HIV.


Most babies who have congenital CMV appear healthy at birth.

A few babies who have congenital CMV who appear healthy at birth develop signs over time — sometimes not for months or years after birth. The most common of these late-occurring signs are hearing loss and developmental delay. A small number of babies may also develop vision problems.

The following signs and symptoms are more common in babies who have congenital CMV and who are sick at birth:

  • Premature birth
  • Low birth weight
  • Yellow skin and eyes (jaundice)
  • Enlarged and poorly functioning liver
  • Purple skin splotches or a rash or both
  • Abnormally small head (microencephaly)
  • Enlarged spleen
  • Pneumonia
  • Seizures

People who have weakened immunity

If your immune system is weakened, you might experience serious problems that affect your:

  • Eyes
  • Lungs
  • Liver
  • Esophagus
  • Stomach
  • Intestines
  • Brain

Healthy adults

Most people who are infected with CMV who are otherwise healthy experience few if any symptoms. When first infected, some adults may have symptoms similar to infectious mononucleosis, including:

  • Fatigue
  • Fever
  • Sore throat
  • Muscle aches

When to see a doctor

See your doctor if:

  • You have a weakened immune system and you're experiencing symptoms of CMV infection. For people who have weakened immune systems, CMV infection can be serious or even fatal. People who have undergone stem cell or organ transplants seem to be at greatest risk.
  • You develop a mononucleosis-like illness while you're pregnant.

If you have CMV but are otherwise healthy, and you're experiencing any mild, generalized illness, you could be in a reactivation period. Self-care, such as getting plenty of rest, should be enough for your body to control the infection.

When your child should see a doctor

If you know you were infected with CMV during your pregnancy, tell your baby's doctor. The doctor will likely assess your baby for hearing or vision problems.


CMV is related to the viruses that cause chickenpox, herpes simplex and mononucleosis. CMV may cycle through periods when it lies dormant and then reactivates. If you're healthy, CMV mainly stays dormant.

When the virus is active in your body, you can pass the virus to other people. The virus is spread through body fluids — including blood, urine, saliva, breast milk, tears, semen and vaginal fluids. Casual contact doesn't transmit CMV.

Ways the virus can be transmitted include:

  • Touching your eyes or the inside of your nose or mouth after coming into contact with the body fluids of an infected person.
  • Sexual contact with an infected person.
  • The breast milk of an infected mother.
  • Organ, bone marrow or stem cell transplantation or blood transfusions.
  • Birth. An infected mother can pass the virus to her baby before or during birth. The risk of transmitting the virus to your baby is higher if you become infected for the first time during pregnancy.

Risk factors

CMV is a widespread and common virus that can infect almost anyone.


Complications of CMV infection vary, depending on your overall health and when you were infected.

Healthy adults

Rarely, CMV causes a healthy adult to develop mononucleosis. Other rare complications for healthy adults include problems with the digestive system, liver, brain and nervous system.

People who have weakened immunity

Complications of CMV infection can include:

  • Vision loss, due to inflammation of the light-sensing layer of the eye (retinitis)
  • Digestive system problems, including inflammation of the colon (colitis), esophagus (esophagitis) and liver (hepatitis)
  • Nervous system problems, including brain inflammation (encephalitis)
  • Pneumonia

Infants who have congenital CMV

An infant whose mother first became infected with CMV during pregnancy is more likely to experience complications. Complications for the baby can include:

  • Hearing loss
  • Intellectual disability
  • Vision problems
  • Seizures
  • Lack of coordination
  • Weakness or problems using muscles


Careful hygiene is the best prevention against CMV. You can take these precautions:

  • Wash your hands often. Use soap and water for 15 to 20 seconds, especially if you have contact with young children or their diapers, saliva or other oral secretions. This is especially important if the children attend child care.
  • Avoid contact with tears and saliva when you kiss a child. Instead of kissing a child on the lips, for instance, kiss on the forehead. This is especially important if you're pregnant.
  • Avoid sharing food or drinking out of the same glass as others. Sharing glasses and kitchen utensils can spread CMV.
  • Be careful with disposable items. When disposing of diapers, tissues and other items that have been contaminated with bodily fluids, wash your hands thoroughly before touching your face.
  • Clean toys and countertops. Clean any surfaces that come in contact with children's urine or saliva.
  • Practice safe sex. Wear a condom during sexual contact to prevent spreading CMV through semen and vaginal fluids.

If you have weakened immunity, you may benefit from taking antiviral medication to prevent CMV disease.

Experimental vaccines are being tested for women of childbearing age. These vaccines may be useful in preventing CMV infection in mothers and infants, and reducing the chance that babies born to women who are infected while pregnant will develop disabilities.

Mar 23, 2022

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