Cytomegalovirus (CMV) is a common virus. Once infected, your body retains the virus for life. Most people don't know they have 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
People who have weakened immunity
If your immune system is weakened, you might experience serious problems that affect your:
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:
- 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.
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.
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)
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
- 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.
Laboratory tests — including tests of blood and other body fluids or tests of tissue samples — can detect CMV.
During pregnancy and after delivery
If you're pregnant, testing to determine whether you've ever been infected with CMV can be important. Pregnant women who have already developed CMV antibodies have a very small chance of a reactivation infecting their unborn children.
If your doctor detects a new CMV infection while you're pregnant, a prenatal test (amniocentesis) can determine whether the fetus has been infected. In this test, your doctor takes and examines a sample of amniotic fluid. Amniocentesis is generally recommended when abnormalities that might be caused by CMV are seen on ultrasound.
If your doctor suspects your baby has congenital CMV, it's important to test the baby within the first three weeks of birth. If your baby has CMV, your doctor likely will recommend additional tests to check the health of the baby's organs, such as the liver and kidneys.
In people who have weakened immunity
Testing for CMV can also be important if you have a weakened immune system. For example, if you have HIV or AIDS, or if you've had a transplant, your doctor may want to monitor you regularly.
Treatment generally isn't necessary for healthy children and adults. Healthy adults who develop CMV mononucleosis generally recover without medication.
Newborns and people who have weakened immunity need treatment when they're experiencing symptoms of CMV infection. The type of treatment depends on the signs and symptoms and their severity.
Antiviral medications are the most common type of treatment. They can slow reproduction of the virus, but can't eliminate it. Researchers are studying new medications and vaccines to treat and prevent CMV.
Preparing for an appointment
Here's some information to help you get ready for your appointment.
What you can do
Before your appointment take these steps:
- Write down any symptoms you or your child is experiencing. Include signs and symptoms even if they seem minor, such as low-grade fever or fatigue.
- Write down questions to ask your doctor. Your time with your doctor is limited, so it can be useful to prepare a list of questions.
For CMV, questions to ask your doctor include:
- What is likely causing my symptoms?
- What tests do I need?
- Is my condition likely temporary or chronic?
- What is the best course of action?
- Will I infect others?
- Are there any restrictions I need to follow?
- I have other health conditions. How can I best manage them together?
What to expect from your doctor
Your doctor will likely ask you a number of questions, including:
- How long have you had your symptoms?
- Do you work or live with young children?
- Have you had a blood transfusion or organ, bone marrow or stem cell transplant recently?
- Do you have a medical condition that might weaken your immune system, such as HIV or AIDS?
- Are you receiving chemotherapy?
- Do you practice safe sex?
- Are you pregnant or breast-feeding?
In addition, if you think you have been exposed during pregnancy:
- When do you think you may have been exposed?
- Have you had symptoms of the condition?
- Have you been tested for CMV before?