Cytomegalovirus (CMV) infection
DEFINITION
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 from person to person through body fluids, such as blood, saliva, urine, semen and breast milk. CMV spread through breast milk usually doesn’t make the baby sick. However, if you are 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.
CAUSES
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:
- Touching your eyes or the inside of your nose or mouthafter coming into contact with the body fluids of an infected person. This is the most common way CMV is spread because it’s absorbed through the mucous membranes.
- Through sexual contact with an infected person.
- Through the breast milk of an infected mother.
- Through organ transplantation or blood transfusions.
- Through the placenta, from an infected mother to her unborn child, or during birth.
SYMPTOMS
Newborns 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
Pregnant women who become infected are at low risk of transmitting the virus to their babies. If it’s the first time you’ve had the infection (primary CMV), risk of transmitting the virus to the baby is higher than it is with reactivated infection. Transmission usually occurs during the first half of pregnancy, usually the first trimester.
Most babies who are infected before they’re born appear healthy at birth, but a few develop signs over time — sometimes not for months or years after birth. The most common of these late-occurring signs is hearing loss. A small number may develop vision impairment as well.
Babies with congenital CMV who are sick at birth tend to be very sick. Signs and symptoms include:
- Yellow skin and eyes (jaundice)
- Purple skin splotches or a rash or both
- Small size at birth (or low birth weight)
- Enlarged spleen
- Enlarged and poorly functioning liver
- Pneumonia
- Seizures
Symptoms in people with compromised immunity
An illness resembling infectious mononucleosis is the most common presentation of CMV in people with weakened immune systems (immunocompromised). CMV also can attack specific organs. Signs and symptoms may include:
- Fever
- Pneumonia
- Diarrhea
- Ulcers in the digestive tract, possible causing bleeding
- Hepatitis
- Inflammation of the brain (encephalitis)
- Behavioral changes
- Seizures
- Coma
- Visual impairment and blindness
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 have a weakened immune system and you’re experiencing what may be signs or symptoms of CMV infection, see your doctor. CMV infection in people with compromised immunity can be fatal. People who are immunocompromised because they have undergone bone marrow or organ transplants seem to be at greatest risk.
- 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
If you know you were infected with CMV during your pregnancy, let your baby’s doctor know. Your doctor should follow your baby to ensure he or she has no vision or hearing problems. However, newborns who are well otherwise are unlikely to develop life-threatening disease later.
