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About Cytomegalovirus and Congenital Cytomegalovirus
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What is CMV?
What is congenital CMV?
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What is CMV?
Cytomegalovirus (CMV) is a common virus. According to the Centers for Disease Control and Prevention (CDC), in the United States nearly 1 in 3 children have been infected with CMV by age 5 years, and over half of adults have been infected with CMV by age 40. Once CMV is in a person's body, it stays there for life and can reactivate. A person can also be reinfected with a different strain of the virus.
Transmission of CMV
CMV is passed from person to person by direct contact with body fluids such as saliva, urine, semen, blood, tears, and breastmilk. The virus can also pass through the placenta during pregnancy.
Young children are a common source of CMV. The virus can stay in a child's body fluids like saliva and urine for months after the infection. People who live with or care for young children may be more likely to get CMV. Avoiding contact with saliva and urine from young children may reduce the risk of CMV infection.
Symptoms of CMV
Most healthy people do not know that they have had a CMV infection because the virus usually doesn't cause any symptoms. Sometimes, people will experience mild, cold-like symptoms such as:
- Fever
- Sore throat
- Fatigue
- Muscle aches
People with weakened immune systems who get CMV may have more serious and even life-threatening symptoms. They may be treated with antiviral medicine.
What is Congenital CMV (cCMV)?
Pregnant people who develop an active CMV infection can unknowingly pass the virus to their growing fetus. When a baby is born with CMV infection, it is called congenital CMV (cCMV). According to the CDC:
- 1 out of every 200 babies is born with cCMV
- cCMV is the most common infectious cause of birth defects in the United States
- 1 out of every 5 babies with cCMV will be born with or develop long-term health concerns
- cCMV is the most common cause of nonhereditary hearing loss in childhood
- In the most severe cases, cCMV can cause pregnancy loss or infant death
Signs of cCMV
About 80% of babies with cCMV appear healthy at birth and never have signs of health concerns caused by the infection.
Some babies with cCMV have signs of the infection at birth. Signs of cCMV infection at birth may include:
- Petechiae (tiny red, purple, or brown spots on the skin)
- Thrombocytopenia (low blood platelet levels)
- Jaundice (yellowing of the whites of the eyes and skin)
- Microcephaly (small head size)
- Small size at birth (low birth weight or intrauterine growth restriction)
- Hepatosplenomegaly (enlarged liver and spleen)
- Retinitis (damaged eye retina)
- Hearing loss
Babies with signs of cCMV at birth are at greater risk of developing long-term health concerns, including:
- Seizures
- Visual impairment
- Hearing loss
- Developmental delay
Some babies with cCMV who appear healthy at birth may develop health concerns months to years later. Later-onset signs of cCMV infection include:
- Hearing loss
- Difficulties with balance
- Visual impairment
Diagnosis of cCMV
Congenital CMV infection is most often diagnosed by detection of CMV DNA in a baby's urine or saliva. The sample must be collected for testing within 21 days of life to confirm a diagnosis of cCMV. After 21 days of age, it is hard to know if a baby was born with cCMV or got CMV infection after birth. Congenital CMV can cause long-term health concerns and hearing loss, but an infection with CMV after birth (known as acquired CMV) usually does not. Additional tests may be recommended to determine the severity of disease if cCMV is diagnosed.
Treatment and Interventions for cCMV
Most babies with cCMV will not need treatment. However, some babies with signs of cCMV at birth may show improved hearing and developmental outcomes after getting antiviral medicine. It is important to talk with your health care provider about the risks and benefits of antiviral medication.
All babies with cCMV may benefit from other interventions including:
- Monitoring for new signs and symptoms, especially hearing loss. Even if your baby passed the newborn hearing screen, they still need regular hearing testing throughout childhood. It is important to find any hearing changes as soon as possible.
- Early intervention services to promote healthy development
- Managing any current signs and symptoms
- Family support