Cytomegalovirus (CMV)


What Is It?

Cytomegalovirus (CMV) is a virus related to the herpes virus. It is so common that almost 100 percent of adults in developing countries and 50 percent to 85 percent of adults in the United States have been infected. The older you are, the more likely you are to be infected with CMV.

Usually CMV is a very mild disease that does not cause any serious problems in healthy children and adults. Symptoms generally are limited to flulike symptoms or an illness similar to mononucleosis.

However, CMV infection can be serious and even fatal in some people, including:

  • People receiving chemotherapy for cancer
  • Adults with diseases that suppress the immune system, such as AIDS
  • People who have received organ or bone marrow transplants
  • Newborn babies of women infected with CMV during pregnancy

Women infected with CMV for the first time during pregnancy can pass the virus to their unborn babies. The virus also can pass from mother to baby in vaginal secretions during delivery and in breast milk after birth. CMV also can pass from person to person in saliva, urine, semen and blood. The virus can contaminate blood transfusions and transplanted organs. Some people, such as those who have had a bone marrow transplant, are at high risk of developing complications if they become infected with CMV. If these people need blood transfusions, they are given specially prepared blood products to decrease the risk of becoming infected with CMV.


There are three classes of CMV infection, each with different symptoms depending on the group affected:

  • Congenital — Up to 40 percent of babies born to women who become infected with CMV during pregnancy will be infected, although not all will have symptoms of CMV at birth. Congenital CMV is the second most common, identifiable cause of mental retardation after Down syndrome.

    Newborns with CMV are likely to be born premature and at a low birth weight. Other problems include a small brain (microcephaly) or other problems of the nervous system that can cause deafness, mental retardation or death. Congenital CMV disease also can cause the liver and spleen to become larger than normal, jaundice (yellow skin and eyes from liver disease), and blood disorders. The most common blood disorder is a low number of platelets, the cells that help the blood to clot. Newborns with CMV also can have a rash that consists of small bruises called petechiae and larger bruises known as purpura. Such babies are sometimes called blueberry muffin babies.

    Babies born to mothers who were infected with CMV before pregnancy are less likely to be born with CMV. Only 0.5 percent to 1.5 percent of such babies are infected, and their problems tend to be less severe than those of babies born to mothers infected during pregnancy. Babies who are infected during birth or through breastfeeding also have less serious problems. Of these babies, approximately one in five will develop some degree of hearing loss.

  • Healthy people — In most instances, CMV infection in healthy people occurs during young adulthood and causes symptoms that mimic mononucleosis. The most common symptoms are fatigue, flulike symptoms, enlargement of the lymph nodes and spleen, loss of appetite, nausea and headache. Most healthy people infected with CMV do not have any symptoms.

  • Immune-suppressed people — People who have had an organ transplant and those with AIDS can develop serious CMV infections that can affect the lungs, esophagus, stomach, intestines, eyes, nervous system and brain. CMV retinitis affects the eye and can cause blindness. Pneumonia caused by CMV can be life threatening. CMV gastrointestinal disease can affect any part of the gastrointestinal tract, including the esophagus, stomach, liver, pancreas and colon, causing ulcers, hepatitis, intestinal obstruction and colitis. Symptoms include painful and difficult swallowing, nausea, vomiting, abdominal pain, yellow skin and watery or bloody diarrhea. CMV infection also appears to cause AIDS to get worse faster.


Doctors may order a blood test, called the TORCH test, for newborns with low birth weight, jaundice, small brain or other problems that can be associated with CMV. The test can be inaccurate, however. The diagnosis of congenital CMV infection is confirmed by testing blood or tissue from the infant within three weeks of birth.

Young, healthy adults usually do not need to be tested because they do not need to be treated and they usually recover over a period of weeks. In some instances, blood tests may be done to check for mononucleosis and to monitor the degree of liver inflammation. Occasionally, Ultrasound testing may be done to monitor the liver or spleen. Routine testing of pregnant women for CMV is not recommended at this time, according to the U.S. Centers for Disease Control and Prevention (CDC).

People with HIV/AIDS have a higher risk of developing CMV retinitis if they have severely weakened immune systems. For this reason, they undergo routine eye examinations to check for the presence of CMV, so that it can be identified early.

Expected Duration

CMV infection is thought to be lifelong, although most healthy people will not have any symptoms.


Pregnant women who care for young children should wash their hands after contact with the saliva, urine, stool or any other secretions of a child and after changing diapers. Breastfeeding is recommended, even in women known to be infected, because the benefits are thought to outweigh the risks of transmitting the disease to the baby, according to the CDC.

The best way for a healthy adult to avoid getting the disease is to follow the same precautions recommended for protecting against all sexually transmitted diseases, including the use of condoms.

People who get a transplanted organ may need to take medication to prevent CMV infection in some instances. Testing of the blood supply for CMV has reduced transmission of the disease. If people with suppressed immune systems need blood transfusions, they likely will be given blood that has had the white blood cells removed, because this lowers the risk of transmission. Also, it is absolutely essential for people with suppressed immune systems to schedule regular eye exams to detect CMV early if it occurs.


Healthy people generally do not need any treatment for CMV.

Although there is no cure for CMV, organ transplant recipients, people with AIDS, and others with immune disorders may need treatment to suppress CMV infection once it has occurred. Treatment may be directed at the underlying immune disorder, because recent experience in treating AIDS patients shows that when a person’s immune response improves, CMV disease also can improve or go away, especially if the count of T-cells (helper immune cells) rises over 100.

Drugs commonly used to treat CMV infection include ganciclovir (Cytovene) and foscarnet (Foscavir). Ganciclovir can be given intravenously (into a vein), orally or as a pellet that is implanted in the eye to treat an infection in the retina. Foscarnet must be given intravenously. Side effects of ganciclovir include suppression of white blood cells (needed to fight infection), red blood cells (that carry oxygen), and platelets (that help the blood to clot). Foscarnet can cause kidney damage, so kidney function needs to be monitored carefully.

When To Call A Professional

Your baby should be seen by a doctor if he or she has yellow skin (jaundice), hearing problems, rash, fever or vomiting. If you are a healthy adult, you should call your doctor if you have abdominal pain, vomiting, fevers that last longer than 48 hours or marked fatigue.

If you have a suppressed immune system, you should see a doctor if you have visual disturbances, mental changes, difficulty or pain swallowing, abdominal pain, vomiting or diarrhea, cough or difficulty breathing.


In healthy people, CMV is mild and goes away on its own. In babies, consequences can last a lifetime or be fatal. People with suppressed immune systems can lose vision or have life-threatening and disabling illnesses that can require lifelong therapy.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.