About CMV and Congenital 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 to a growing fetus during pregnancy.

Babies and young children are a common source of CMV because they often get CMV from other kids. The virus can stay in a child's body fluids, like saliva and urine, for months after the infection. Children can pass the virus to parents or caregivers even if they don’t seem sick. People who live with or care for young children are more likely to get 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.

Most babies with congenital CMV appear healthy at birth and never have health concerns caused by the infection.

Some babies with congenital CMV have signs of the infection at birth, such as:

• Petechiae (tiny red, purple, or brown rash on the skin)
• Thrombocytopenia (low blood platelet levels)
• Jaundice (yellowing of the whites of the eyes and skin)
• Microcephaly (small head size)
• Low birth weight  
• Hepatosplenomegaly (enlarged liver and spleen)
• Retinitis (damaged eye retina)

Babies with signs of congenital CMV at birth are at greater risk of long-term health concerns, such as:

• Seizures
• Visual impairment
• Developmental and motor delay
• Lack of coordination or muscle weakness

Hearing Loss

Hearing loss is common in children with congenital CMV, even in those who passed their newborn hearing test or didn’t have other signs at birth. Hearing loss can impact one or both ears and may be present at birth or develop later. It is important that all children with congenital CMV have regular hearing checks so that any change can be found as early as possible.

Congenital CMV infection is most often diagnosed by detection of CMV in a baby's urine. The sample must be collected for testing within 21 days of life to confirm a diagnosis of congenital CMV. If a test is collected after 21 days of age, it is hard to know if a baby was born with CMV or got a 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.

As of February 2023, all babies born in Minnesota are screened for CMV as part of the Minnesota newborn screening panel. If CMV is detected on the newborn screen, the baby’s health care provider is notified, and a urine test is collected before the baby is 21 days old to check for the virus.

Some babies with signs of congenital CMV at birth may show improved hearing and developmental outcomes after getting treatment with antiviral medicine. It is important to talk with your baby’s health care provider about the risks and benefits of antiviral medication.

All babies with congenital CMV may benefit from other interventions such as:

• Monitoring for new signs and symptoms, especially hearing loss
• Early intervention services to promote healthy development
• Managing any current signs and symptoms
• Family support