Cytomegalovirus is a common herpes virus. Many people do not know they have it because they may have no symptoms.
But the virus, which remains dormant in the body, can cause complications during pregnancy and for people with a weakened immune system.
The virus spreads through bodily fluids, and a pregnant person can pass it on to the unborn baby.
Also known as HCMV, CMV, or human herpesvirus 5 (HHV-5), cytomegalovirus is the most commonly transmitted virus to a developing fetus.
The Centers for Disease Control and Prevention (CDC) estimate that over 50% of adults in the United States have contracted the virus by 40 years old. It affects males and females equally, at any age and regardless of ethnicity.
The symptoms will depend on the type of CMV.
Most people with acquired CMV have no noticeable symptoms, but if symptoms do occur, they may include:
- night sweats
- tiredness and uneasiness
- sore throat
- swollen glands
- joint and muscle pain
- low appetite and weight loss
Symptoms will generally go away after 2 weeks.
Symptoms of recurring CMV vary, depending on which organs the virus has affected. Areas likely to be affected are the eyes, lungs, or digestive system.
Symptoms may include:
- diarrhea, gastrointestinal ulcerations, and gastrointestinal bleeding
- shortness of breath
- pneumonia with hypoxemia, or low blood oxygen
- mouth ulcers that can be large
- problems with vision, including floaters, blind spots, and blurred vision
- hepatitis, or inflamed liver, with prolonged fever
- encephalitis, or inflammation of the brain, leading to behavioral changes, seizures, and even coma.
A person with a weakened immune system who experiences any of these symptoms should seek medical attention.
According to the National CMV Foundation, around 90% of babies born with CMV have no symptoms, but 10–15% of them will develop hearing loss, typically during their first 6 months of life. The severity ranges from slight to total hearing loss.
In half of these children, the virus will affect just one ear, but the rest will have hearing loss in both ears. Hearing loss in both ears can lead to a higher risk of speech and communication problems later on.
If there are symptoms of congenital CMV at birth, they may include:
- spots under the skin
- Purple skin splotches, a rash, or both
- enlarged liver
- enlarged spleen
- low birth weight
Some of these symptoms are treatable.
CMV will impact the brain in about 75% of babies born with congenital CMV. This may lead to challenges later in life.
Conditions that they may face include:
Scientists have been searching for a CMV vaccine, but as yet, there is no cure.
People with acquired CMV who contract the virus for the first time can use over-the-counter (OTC) pain relief medicines, such as Tylenol (acetaminophen), ibuprofen, or aspirin, to relieve symptoms and should drink plenty of fluids.
People with congenital or recurring CMV can use antiviral medications, such as ganciclovir, to slow the virus’s spread.
These medications may have adverse effects. If there is extensive organ damage, hospitalization may be necessary.
Newborns may need to stay in the hospital until their organ functions return to normal.
The following precautions may help lower the risk of contracting CMV:
- Wash the hands regularly with soap and water.
- Avoid kissing a young child, including tear and saliva contact.
- Avoid sharing glasses and kitchen utensils, for example, passing around a drink.
- Dispose of diapers, paper handkerchiefs, and similar items carefully.
- Use a condom to prevent the spread of CMV via vaginal fluids and semen.
The CDC urges parents and caregivers of children with CMV to seek treatment as early as possible, whether it is taking medication or attending all appointments for services, such as hearing checks.
There are three main types of CMV infections: acquired, recurring, or congenital.
- Acquired, or primary, CMV is when a person gets the virus for the first time.
- Recurring CMV is when the person already has the virus. The virus is dormant and then becomes active due to a weak immune system.
- Congenital CMV is when a person has the virus during pregnancy and passes it on to the fetus.
CMV is generally not a problem, except when it affects an unborn child or a person with a weak immune system, such as a recent transplant recipient or a person with HIV.
If a person with HIV contracts CMV, it can lead to organ failure, eye damage, and blindness. Improvement in antiviral medication has reduced the risk in recent years.
People who have received organ and bone marrow transplants have to take immunosuppressants to lower their immune systems so that their bodies do not reject the new organs. Dormant CMV can become active in these people and lead to organ damage.
Transplant recipients may receive antiviral medicines as a precaution against CMV.
A pregnant person can pass the virus to the fetus. This is called congenital CMV.
According to the CDC, around 1 in 200 babies are born with the virus.
Most of these infants will have no signs or symptoms, but around 20% of them will have symptoms or long-term health complications, including learning difficulties.
The symptoms may be severe, and they include vision and hearing loss, small head size, weakness, difficulty using muscles, coordination problems, and seizures.
Acquired cytomegalovirus can spread between people through bodily fluids, such as saliva, semen, blood, urine, vaginal fluids, and breast milk.
A person can also contract the virus by touching a surface that has the virus on it and then touching the inside of the nose or mouth.
Most humans contract the virus during childhood, at daycare centers, nurseries, and other places where children come into close contact with each other. However, by this age, the child’s immune system can normally deal with an infection.
Recurring CMV can occur in people with a weakened immune system due to HIV, organ transplantation, chemotherapy, or taking oral steroids for over 3 months.
Congenital CMV normally occurs when a female contracts CMV for the first time, either during pregnancy or shortly before conceiving.
Occasionally, a dormant CMV may recur during pregnancy, especially if the person has a weakened immune system.
A blood test can detect the antibodies that the body creates when the immune system responds to CMV’s presence.
A pregnant person has a minimal risk that reactivation of CMV may affect her developing baby. If a doctor suspects that a pregnant person has CMV, they may suggest an amniocentesis. This involves extracting a sample of amniotic fluid to find out whether the virus is present.
If the doctor suspects congenital CMV, they will test the baby within the first 3 weeks of life. Testing later than 3 weeks will not be conclusive for congenital CMV because the baby may have contracted the virus after birth.
Anyone with a weakened immune system should have a test, even if the virus is not active. Regular monitoring for CMV complications will include testing for vision and hearing problems.
Healthy people rarely become significantly sick from CMV.
However, people with a weakened immune system may develop CMV mononucleosis, a condition in which there are too many white blood cells with a single nucleus.
Symptoms include sore throat, swollen glands, swollen tonsils, tiredness, and nausea. It can cause liver inflammation, or hepatitis, and spleen enlargement.
CMV mononucleosis is similar to classic mononucleosis caused by the Epstein-Barr Virus. (EBV). EBV mononucleosis is also known as glandular fever.
Other complications of CMV are:
- gastrointestinal problems, including diarrhea, fever, abdominal pain, colon inflammation, and blood in the feces
- liver function problems
- central nervous system (CNS) complications, such as encephalitis, or inflammation of the brain
- pneumonitis, or inflammation of lung tissue.