Cytomegalovirus (CMV)

Cytomegalovirus (CMV) is a common infection caused by a type of herpes virus. Pregnant people infected with CMV can give birth to a baby with congenital CMV. Congenital CMV can cause hearing loss and developmental issues. CMV can cause serious complications in people who have a compromised immune system, such as transplant recipients.


What is cytomegalovirus?

Cytomegalovirus (CMV) is an illness you get from a type of herpes virus (an organism that uses your cells to make more copies of itself). Many people will get infected in their lifetime, but most will have mild or no symptoms. CMV can cause serious complications in people living with a compromised immune system.

People who are pregnant can pass CMV to the fetus, which can cause congenital CMV. Congenital CMV is a condition that’s present at birth and can lead to hearing loss or developmental issues.


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Who does cytomegalovirus affect?

While CMV can infect anyone, most people won’t have symptoms. CMV is most dangerous in pregnancy and for those with weakened immune systems, like people living with HIV or those who’ve had an organ or stem cell transplant.

CMV in pregnancy

If you get cytomegalovirus during pregnancy or shortly before getting pregnant, you can pass the virus through the placenta to the fetus. This increases the risk of pregnancy loss (miscarriage) and your child being born with health issues. Complications of being born with CMV include vision or hearing loss and developmental delays.

CMV when you have a compromised immune system

If you’re living with HIV or you’re taking immune-suppressing medications for an organ or stem cell transplant, your immune system can’t easily fight off infections like cytomegalovirus. This means you have a weakened immune system (immunocompromised).

If you’ve had CMV in the past, the virus can stay in your body, inactive. When your immune system is weakened, it can reactivate and cause you to get sick. While most people can fight off CMV without symptoms, a new or reactivated infection can cause serious complications in someone with a weakened immune system.

Who is at higher risk for CMV?

You’re at higher risk for cytomegalovirus if you:

  • Are under the age of 5. About 33% of children have had a CMV infection by the age of 5.
  • Work with or live with children under the age of 5.
  • Have a compromised immune system. This includes those living with HIV/AIDS and people who’ve had a stem cell or organ transplant.
  • Live in close contact with many other people (crowded conditions).

How common is CMV?

CMV is a common infection, but most people who are infected don’t have any symptoms. In the U.S. and Canada, experts estimate that:

  • Half of all people will have had a cytomegalovirus infection by age 40.
  • Up to 90% of all people will be infected by age 80.
  • About 1 in 200 babies is born with CMV each year, though only 10% (1 in 10) will have symptoms at birth.

Symptoms and Causes

What are the symptoms of cytomegalovirus in humans?

Symptoms of CMV vary depending on:

  • Whether the person who’s infected has a healthy or compromised immune system.
  • Whether the infection is present at birth (congenital) or happens later.

CMV symptoms with a healthy immune system

Most people who have a healthy immune system don’t get symptoms of CMV. Those with noticeable symptoms often have CMV mononucleosis, which can cause:

  • Extreme tiredness (fatigue).
  • Muscle aches.
  • Sweating.
  • Headache.
  • Sore throat.
  • Swollen lymph nodes.
  • Rash.

CMV symptoms with a compromised immune system

If you have a weakened immune system (immunocompromised), you might get a new CMV infection or have a previous infection that reactivates when your body is no longer able to fight it off easily. Symptoms depend on what part of your body the virus infects and could include:

  • Fever.
  • Fatigue.
  • CMV pneumonitis (shortness of breath, cough, muscle aches, weakness).
  • CMV retinitis (blurry vision or loss of vision).
  • CMV gastritis or colitis (stomach pain, blood in your poop, nausea, vomiting, diarrhea).
  • CMV encephalitis (seizures, headaches, confusion).

Congenital CMV symptoms

Congenital (present at birth) CMV is when the virus passes from a person who’s pregnant to the fetus. Some babies won’t have any symptoms at birth but go on to develop certain symptoms later on. Symptoms present at birth include:

What causes cytomegalovirus?

A type of herpes virus causes CMV infections. It can prevent your organs from working properly, or from developing properly in a fetus. Because of the way the virus hides in your body, you can have symptoms when you’re initially infected (primary infection) or at a later time (reactivation).

How do you get CMV?

You get CMV from the body fluids of someone else who’s infected. This includes spit (saliva), pee (urine), blood, human milk and semen. Common ways CMV transmits from person to person include:

  • Through direct contact with pee and spit. Experts think this is the most common way that young children and people who are pregnant get the infection.
  • Through sex.
  • From a person with an active CMV infection to a baby through breastfeeding/chestfeeding.
  • From a blood transfusion or organ transplant.

Is cytomegalovirus an STI?

CMV isn’t considered a sexually transmitted infection (STI). Sex can transmit CMV, but it’s not the most common way to get infected.


Diagnosis and Tests

How is cytomegalovirus diagnosed?

Healthcare providers use blood, urine (pee) or saliva (spit) tests to diagnose CMV. Since it usually causes mild symptoms, most people won’t need to be tested.

Your healthcare provider may test you for CMV if you have a weakened immune system. Your child’s healthcare provider may test them in their first few weeks of life if they have symptoms of congenital CMV.

What tests will be done to diagnose CMV?

To diagnose CMV, your healthcare provider may order some or all of these tests:

  • Blood tests. A provider usually uses blood tests to diagnose CMV in adults. Your provider will use a needle to take blood from your vein. They’ll send it to a lab to look for signs of infection.
  • Urine tests. A provider might use a urine (pee) test to diagnose CMV in a newborn baby. Your baby’s provider will either collect a sample or give you instructions on how to collect one. They’ll send the sample to a lab to look for signs of CMV.
  • Saliva tests. A provider might use a saliva (spit) test to diagnose CMV in a newborn baby. Your baby’s provider will use a stick with a soft tip (swab) to gently collect a small amount of spit from the inside of your baby’s mouth. They’ll send the sample to a lab to look for signs of CMV.

Management and Treatment

How is CMV treated?

A provider can treat CMV with the antiviral medications ganciclovir (GCV) or valganciclovir (VGC). These drugs are given directly into your vein (IV infusion) or swallowed in a pill. Providers usually only treat CMV in people who have a compromised immune system or babies who are born with symptoms of CMV. In people with healthy immune systems, CMV usually goes away without treatment.

Antiviral medications can’t reverse any damage that’s already been done. They can lessen the risk of health problems in babies born with CMV but may not completely prevent them. Children with congenital CMV can also be treated with speech and occupational therapy to manage the effects of hearing loss and developmental issues.

How long does it take for CMV to go away?

Even if you have a healthy immune system, symptoms of CMV can last for a long time. You may feel run down, tired or weak for several weeks or months.


How can I prevent cytomegalovirus?

People who are pregnant and people with a compromised immune system can reduce their risk of CMV by avoiding contact with other people’s body fluids. Specific ways to reduce your risk include:

  • Don’t share food or forks, spoons, cups or other eating utensils with a child.
  • Don’t put a child’s pacifier in your mouth.
  • Wash your hands after changing a diaper or helping a child go to the bathroom. Use warm water and soap.
  • Use a condom when having oral, anal or vaginal sex, even if you always have sex with the same partner.
  • If you’ve received an organ transplant, your provider may treat you with antiviral medications to prevent CMV. They may monitor your blood for infections so that they can treat you as soon as possible if you do get infected.

Outlook / Prognosis

What can I expect if I have CMV?

The outlook for CMV varies depending on whether you or your child were born with CMV and whether you have a weakened immune system. Your provider can help you know what to expect in your specific situation.

Outlook for CMV when you have a healthy immune system

People with healthy immune systems who develop symptoms of CMV can be sick for one week to several months. Serious complications from CMV are rare.

Outlook for congenital CMV

About 50% of children who have symptoms of CMV at birth will have lasting health effects. These often include hearing or vision loss and developmental differences. Hearing loss can develop later even if your child didn’t have symptoms of CMV at birth. Infants with severe symptoms may have life-threatening complications of CMV.

Outlook for CMV when you have a weakened immune system

If you have a weakened immune system, how a CMV infection will affect you depends on how soon it’s treated and where the infection is in your body. You’ll probably need to be hospitalized for treatment. Early treatment of a CMV infection gives you the best chance of a full recovery.

Complications of CMV infections

People with weakened immune systems, especially those who’ve received a stem cell transplant, are most likely to experience serious or life-threatening complications of cytomegalovirus. Complications include:

  • Lasting cognitive issues, including trouble focusing, remembering and problem-solving.
  • Partial or complete loss of vision.
  • A tear (perforation) in your esophagus or intestines.
  • Pneumonia, possibly leading to respiratory failure.
  • Rejection of donor organ.

Living With

How do I take care of myself with CMV?

If you’ve been diagnosed with cytomegalovirus, your symptoms may mean you need to rest and take breaks more often than you usually would. Ask your provider how to best manage your symptoms.

If you have a compromised immune system, your provider will monitor you closely. If you’re able to be at home, they’ll let you know how to keep an eye on your symptoms and when to call them.

How do I take care of my child if they’re diagnosed with congenital CMV?

If your child was diagnosed with CMV at birth, work closely with their pediatrician and other providers to make sure they get appropriate treatment. Starting speech and occupational therapy as soon as possible can minimize the impact of future hearing loss or developmental delays.

How long does CMV stay in your body?

Once infected, CMV can stay in your body, inactive, for the rest of your life. If you have a weakened immune system, it can reactivate and cause serious symptoms or organ damage.

When should I see my healthcare provider?

Contact your provider right away if you have symptoms of CMV and have a compromised immune system, or if you think your baby has symptoms of congenital CMV. Talk to your healthcare provider about steps you can take to prevent CMV if you:

  • Have a compromised immune system.
  • Have or will have a stem cell or organ transplant.
  • Are pregnant or plan to become pregnant.

What questions should I ask my doctor?

  • What special precautions should I take to prevent CMV?
  • Should my child be tested for CMV?
  • What therapies do you recommend for congenital CMV?
  • What can I expect if my child has congenital CMV?

A note from Cleveland Clinic

Many people will get cytomegalovirus in their lifetime without knowing it. But pregnant people and those with a weakened immune system should take special care to avoid infection. Early identification and treatment are the best ways to manage the effects of CMV and to prevent serious complications in those most at risk. Talk to your healthcare provider about how to reduce your risk of CMV based on your specific circumstances.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 10/20/2022.

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