Cytomegalovirus (CMV)

Medically Reviewed by Zilpah Sheikh, MD on March 07, 2024
7 min read

Cytomegalovirus (CMV) is a common virus. Over half of adults in the U.S. have it by age 40, but people of any age can get it. CMV spreads easily through an infected person's saliva or other body fluids.

If you have a healthy immune system that can easily control the virus, it usually doesn't cause problems. But it can sicken people with weakened immune systems.

In people who have advanced HIV, CMV can cause an eye infection called retinitis, which may lead to blindness. CMV retinitis is what’s known as an AIDS-defining condition. The virus could also affect your intestinesesophaguslungsbrain, or nerves.

Types of CMV infection

There are different types of cytomegalovirus infection.

Congenital. This is when a baby gets CMV from their mother before birth. About 1 in 200 babies are born with a CMV infection.

Primary. This is when someone gets CMV for the first time. It usually doesn’t cause symptoms, but some people may have signs that look like mononucleosis.

Reactivation. An infection that has been dormant can become active again when your immune system is weakened. It can happen if you have advanced HIV, are in treatment for cancer, or have an organ transplant.

Most healthy people who get CMV don't know it. You could have minor symptoms. Those who are most likely to have symptoms include:

  • Newborns who get CMV before birth
  • Infants infected during or soon after birth
  • Recipients of organ, bone marrow, or stem cell transplants
  • Those infected with HIV

General symptoms of primary CMV

 If you have symptoms of primary CMV, they're mild and include:

Less common symptoms of primary CMV

In rare cases, CMV can also cause:

  • Changes to your personality
  • Trouble concentrating
  • Shortness of breath
  • Dry cough
  • Anemia
  • Rash
  • Enlarged spleen

Symptoms of congenital CMV

Babies born with CMV usually look healthy when they're born. But 1 in 5 will show signs of the infection at birth or over time. These symptoms include:

  • Premature delivery
  • Small size or low birth weight
  • Bruise-like rashes
  • Yellow skin or eyes (jaundice)
  • Swollen liver and spleen
  • Small head (microcephaly)
  • Seizures
  • Hearing loss
  • Pneumonia
  • Liver inflammation (hepatitis)
  • Developmental delay
  • Motor delay
  • Vision problems

In severe cases, CMV can lead to a miscarriage.

Symptoms of CMV with HIV

If you also have advanced HIV, CMV can affect different parts of your body. You could have:

  • Blind spots or moving black spots (floaters) in your eyesight
  • Blurry vision
  • Loss of central vision
  • Blindness
  • Diarrhea that may be bloody
  • Belly pain
  • Trouble swallowing or painful swallowing because of ulcers in your mouth or esophagus
  • Confusion
  • Lower back pain
  • Weight loss
  • Fatigue
  • Weakness in your legs
  • Headache
  • Trouble concentrating
  • Fever
  • Weight loss
  • Shortness of breath
  • Apathy
  • Withdrawal
  • Changes in personality

If you have HIV, you probably won’t get sick with CMV unless your CD4 (a type of white blood cell) count is below 100.

CMV is part of the herpesvirus family. This group of viruses also includes:

Herpes simplex virus 1. The cause of oral herpes or cold sores.

Herpes simplex virus 2. The cause of genital herpes.

Varicella-zoster virus. The cause of chickenpox and shingles.

Epstein-Barr virus. The cause of infectious mononucleosis.

All of these viruses can stay in your system for life in a hidden or inactive, form. They can stick around in your cells without making you sick or causing damage. But latent herpesviruses including CMV can be dormant for years and then reactivate.

You probably won't catch CMV from casual contact. But you can get it by touching your eyes, nose, or mouth after having contact with an infected person's:

You can also get cytomegalovirus through:

  • Sexual contact
  • Blood transfusions
  • Organ transplants

CMV spreads easily in places with lots of young children, such as day care centers, so anyone who spends time there is at higher risk of getting it. You’re also more likely to get the virus if your immune system is weakened because of a medication or another health condition.

Your doctor will order tests such as:

Blood and urine tests. These include CMV antigen (a part of the virus), a virus culture, or PCR (a molecular test). Serologic tests look for IgM and IgG antibodies, which are made by your immune system to fight CMV, although most healthy people also have them.

Biopsy. Your doctor takes a small sample of tissue from your intestines, esophagus, or lung and look at it under a microscope.

Eye tests. Your doctor will check for inflammation in your retina.

Imaging tests. CT or other scans can capture changes in your lungs or brain.

If you're healthy, usually you won't need treatment for CMV. Most people get better without any medicine. If you have a weakened immune system or your newborn has CMV, a doctor may suggest treatment depending on how severe the symptoms are. Antiviral medicines are the most common way to treat it. They can't make the virus go away, but they can slow it down.

Your doctor might prescribe drugs including:

These drugs generally can't cure the disease, but they can help if you have a weak immune system and symptoms from a CMV infection. If you have advanced HIV, they can control the infection while you get antiretroviral therapy (ART) for your HIV infection.

Depending on the medicine, you could have side effects including:

Most importantly, if you take ART early in an HIV infection, the drugs will keep it from getting worse and will keep you from getting CMV in the first place.

If you have retinitis because of CMV, your doctor may give you strong medications intravenously (through a vein) for a couple of weeks, a process called induction therapy. After a while, they may switch you to pills.

You might have medication injected into your eye if your vision is in danger.

It’s rare, but CMV can cause complications including:

In people with HIV, complications include:

Complications in babies born with CMV include:

  • Learning problems
  • Cerebral palsy or trouble with muscle tone and coordination
  • Seizures
  • Hearing loss
  • Developmental or motor delays
  • Vision problems

There’s no cure for CMV. The virus stays inactive in your body and can cause more problems later. This reactivation is most common in people who’ve had stem cell and organ transplants.

Your outlook depends on your overall health. In people who have strong immune systems, CMV symptoms almost always go away on their own.

Congenital CMV can have lifelong effects. The risks are highest if you have your first CMV infection while you are pregnant.

If you have a weakened immune system, you might need treatment for the rest of your life to prevent complications.

You can protect yourself from a CMV infection by taking measures similar to those for preventing any other virus. This includes practicing careful hygiene, including:

  • Washing your hands often with soap and water for 15-20 seconds
  • Avoiding contact with tears or saliva, especially in young kids
  • Avoiding shared food or drinking glasses
  • Washing your hands after touching dirty diapers, tissues, or other items with bodily fluids on them
  • Keeping toys, countertops, and other surfaces clean
  • Using condoms during sex

CMV prevention and HIV

CMV was once the most common viral opportunistic infection (an illness that gets worse or happens more often in people with weakened immune systems) tied to HIV. Now, ART can help keep your CD4 count up and your immune system strong. It can also help stop retinitis from coming back.

If you have advanced HIV, your doctor might also give you medicine to prevent CMV, in addition to ART. But it's expensive, causes severe side effects sometimes, and may not work well. The most important thing is to take your ART medications daily as prescribed.

Talk to your doctor about your chance of getting CMV if you're having a blood transfusion.

CMV is a common virus and, for most people, it doesn't make you sick. You may have reason for concern if you get an active CMV infection when you're pregnant or have a weak immune system. You can take steps to lower your risk for infection by washing your hands and avoiding contact with bodily fluids. See your doctor if you think you have symptoms of a CMV infection or know you were infected during pregnancy.

  • Is cytomegalovirus an STD?

You can get CMV through sex. But that isn't how people usually get it. It's not considered a sexually transmitted disease (STD) or infection (STI).

  • Can cytomegalovirus be cured?

You can't cure CMV. For most people, it doesn't cause illness. But if you have an active infection and symptoms, some medicines may help.

  • How do you treat cytomegalovirus in adults?

Your doctor can prescribe you some antiviral medicines. Usually, you'll only need to take medicine for CMV if your immune system is weak.

  • Is cytomegalovirus always contagious?

CMV can spread from one person to the next through bodily fluids. But it doesn't often spread through casual contact. It usually takes more direct and prolonged contact with saliva, urine, or breast milk. CMV can spread more easily in young children, especially in day care settings. 

  • How do you fight cytomegalovirus?

There is no vaccine or cure for CMV. The best way to protect yourself is by washing your hands and taking steps to avoid contact with bodily fluids.