Cytomegalovirus (CMV) infection
Cytomegalovirus (CMV) infection
Cytomegalovirus (CMV) is a common virus that can infect almost anyone. Most people don't know they have CMV because it rarely causes symptoms. However, if you're pregnant or have a weakened immune system, CMV is cause for concern.
Once infected with CMV, your body retains the virus for life. However, CMV usually remains dormant if you're healthy. CMV spreads through body fluids, such as blood, saliva, urine, semen and breast milk. People with weak immune systems have a greater risk of becoming ill from CMV. If you're pregnant and develop an active infection, you can pass the virus to your baby.
There's no cure for CMV, but drugs can help treat newborns and people with weak immune systems.
Newborns who have been infected with CMV in the womb (congenital CMV), babies who become infected during birth or shortly after birth (perinatal CMV) — such as through breast-feeding — and people with weakened immune systems are more at risk of developing signs and symptoms than are healthy adults.
Symptoms in babies
Babies with congenital CMV who are affected at birth tend to be very sick. Signs and symptoms include:
Symptoms in people with compromised immunity
Most people infected with CMV who are otherwise healthy experience few if any symptoms. When first infected, some adults may have symptoms similar to mononucleosis, including fatigue, fever and muscle aches.
When to see a doctor
If you develop a mononucleosis-like illness while you're pregnant, see your doctor so that you can be evaluated for CMV infection. Talk to your doctor about the possible risks to your unborn baby if you have the virus.
If you have CMV but are otherwise healthy, and you're experiencing any mild, generalized illness, you could be in a reactivation period. Practical self-care steps, such as getting plenty of rest, should be enough for your body to control the infection. You probably don't need to see your doctor.
When your child should see a doctor
Cytomegalovirus is related to the viruses that cause chickenpox, herpes simplex and mononucleosis. Once you're infected with CMV, the virus remains with you for life, but it's not always active. CMV may cycle through periods during which it lies dormant and then reactivates. If you're healthy, it mainly stays dormant. You can pass the virus to others during reactivation.
Transmission of the virus occurs through exposure to body fluids — including blood, urine, saliva, breast milk, tears, semen and vaginal fluids — not by casual contact.
The virus can spread in a number of ways:
CMV is a widespread and common virus that can infect almost anyone. But healthy children and adults who contract the infection usually have few if any symptoms, so CMV often goes undiagnosed.
In the rare cases in which CMV causes a healthy person to become very sick, the infection may cause the following complications:
Complications arising from newborn CMV infection include:
Preparing for your appointment
Appointments can be brief, so it's good to be well prepared. Write down any signs and symptoms you're experiencing — even if they seem minor, such as low-grade fever or fatigue. You should also write down any questions you have for your doctor.
Preparing a list of questions for your doctor will help you make the most of your time together. For CMV, some basic questions to ask your doctor include:
Don't hesitate to ask other questions that occur to you.
What to expect from your doctor
In addition, if you think you have been exposed during pregnancy:
Tests and diagnosis
If you have symptoms of CMV, tests can determine whether you have the disease. Blood tests can detect proteins in your blood (antibodies) that are created by your immune system when you have CMV. Other tests can locate the virus itself in blood, other body fluids or a tissue biopsy.
Screening and testing for your baby
When new infection is detected during pregnancy, you may consider amniocentesis, in which your doctor obtains and examines a sample of amniotic fluid to determine whether the fetus has the infection. Occasionally the need for such testing arises when abnormalities that may be caused by CMV or other infectious diseases are seen on ultrasound.
If you or your doctor thinks your baby may have been born with CMV (congenital CMV), it's important that he or she be tested within the first three weeks of birth. If you wait longer, tests won't be conclusive for congenital CMV, because it's possible your baby could have contracted the infection by nursing or by exposure to siblings or others who may be shedding the virus.
Screening and testing if you're immunocompromised
Treatments and drugs
There's no cure for CMV, and treatment for the virus generally isn't necessary or recommended for healthy children and adults.
Newborns and people with compromised immune systems, however, do need treatment when they're experiencing symptoms of CMV infection, such as pneumonia. The kind of treatment depends on the symptoms and their severity.
If treatment is needed, it's most often in the form of antiviral drugs. Antiviral drugs slow down the virus reproduction, but can't destroy it. Researchers are studying new medications and vaccines to treat and prevent CMV.
Careful hygiene is the best prevention against CMV. Health care workers have the greatest opportunity for exposure, but because of precautions used in the health care setting, their risk of acquiring the disease is very low.
You can take these precautions to help prevent CMV infection:
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. If you have a compromised immune system, you may benefit from taking antiviral medication to prevent CMV disease.
Last Updated: 2011-04-30
© 1998-2014 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use