What Is Cytomegalovirus?
Cytomegalovirus (CMV) is a common virus. Over half of adults in the U.S. have it in their body by the time they turn 40. CMV is easily spread through an infected person’s saliva or other body fluids. It’s related to the herpes virus, which gives you cold sores.
If you have a healthy immune system that can easily control the virus, it usually doesn't cause problems. But it can make people who have weakened immune systems sick.
In people who have advanced HIV, CMV can cause an eye infection called retinitis that can lead to blindness. CMV retinitis is what’s known as an AIDS-defining condition. It can also affect your intestines, esophagus, lungs, brain, or nerves.
There are different types of cytomegalovirus infection.
- Congenital. This is when a baby gets CMV from its mother before birth.
- Primary. This is the first time someone gets CMV. 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 or in situations like during treatment for cancer or for an organ transplant.
Most healthy people who get CMV don't know it. If you have symptoms, they're mild and include:
Babies born with CMV might have:
- Premature delivery
- Small size
- Swollen liver and spleen
- Small head (microcephaly)
- Hearing loss
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
- Belly pain
- Trouble swallowing or painful swallowing
- Weakness in your legs
In rare cases, CMV can also cause:
If you have HIV, you probably won’t get sick with CMV unless your CD4 count, a type of white blood cell, is below 100.
You can also get cytomegalovirus through:
- Sexual contact
- Blood transfusions
- Organ transplants
CMV spreads easily in places with lots of young children, like 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.
Tests can check for the virus in your blood and urine. These include CMV antigen (a part of the virus), a virus culture, or PCR (a molecular test). Serologic tests look for antibodies that your immune system makes to fight CMV, although most healthy people also have them. Your doctor can also do a biopsy -- taking tissue from your intestines, your esophagus, or your lung -- and look at it under a microscope.
When 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.
Your doctor might prescribe drugs including:
These drugs generally can't cure the disease if you have advanced HIV, but they can control it while you get antiretroviral therapy (ART) for your HIV infection.
Depending on the medicine, you could have side effects including:
- Low white blood cell count (neutropenia), which raises your chance for other infections
- Feeling tired from low red blood cell count (anemia)
- Upset stomach or throwing up
- Kidney problems
Most important, 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.
It’s rare, but CMV can cause complications including:
- Guillain-Barre syndrome
- Brain inflammation (encephalitis)
- Heart inflammation (myocarditis)
In people with HIV, complications include:
- Skin rashes and lesions
- Problems in the nerves, esophagus, lungs, colon, or mucous membranes
- Brain swelling
Complications in babies born with CMV include:
CMV was once the most common viral opportunistic infection -- illnesses that are worse or happen 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. But it's expensive, sometimes causes severe side effects, and may not work well. The most important thing is to take your ART medications.
Talk to your doctor about your chance of getting CMV if you're having a blood transfusion.