Cytomegalovirus (CMV) in Newborns: Prevention, Screening, and Treatment

Cytomegalovirus (CMV) is a common virus. According to the American Academy of Pediatrics, nearly 1 in 3 children have been infected by age 5, and more than half of adults have been infected with CMV by age 40.

Once CMV enters a person's body, it remains there for life and can reactivate. A person can also be reinfected with a different strain of the virus.

CMV passes from person to person through direct contact with body fluids such as saliva, urine, semen, blood, tears, and breast milk. The virus can also pass through the placenta to a growing baby during pregnancy.

Babies and young children are a common source of CMV because they often contract it from other children. The virus can remain in a child's body fluids, such as saliva and urine, for months after infection. Children can pass the virus to parents or caregivers even when they don't appear sick. People who live with or care for young children are at higher risk of contracting CMV.

Most healthy people don't know they've had a CMV infection because it usually doesn't cause symptoms. When symptoms do occur, they are often mild and flu-like, including:

• Fever
• Sore throat
• Fatigue
• Muscle aches

People with weakened immune systems who contract CMV may experience more serious, and even life-threatening, symptoms affecting the eyes, lungs, liver, esophagus, stomach, and intestines. These individuals may be treated with antiviral medication.

You can lower your risk of contracting CMV by reducing contact with other people's body fluids — especially saliva and urine from babies and young children. To help protect yourself:

• Avoid sharing food, utensils, cups, or pacifiers with a child.
• Wash your hands with soap and water after changing diapers or helping a child use the toilet.

When a baby is born with CMV, the infection is called congenital CMV (cCMV). Pregnant individuals who develop an active CMV infection can unknowingly pass the virus to their growing baby.

About 1 in 200 babies is born with cCMV, which means approximately 300 babies are born with cCMV in Wisconsin each year. About 1 in 5 babies with cCMV will have birth defects or other long-term health problems.

Most babies with congenital CMV appear healthy at birth and never experience health concerns related to the infection.

Some babies show signs of the infection at birth, such as:

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

Babies with signs of congenital CMV at birth face a greater risk of long-term health concerns, including:

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

Hearing loss is the most common symptom of cCMV. It may be detected at birth or may develop and progress over time.

CMV is detected in a person's body fluids. In infants, cCMV is most often diagnosed by detecting the virus in a baby's urine. A sample must be collected within 21 days of birth to confirm a diagnosis of cCMV. If the sample is collected after 21 days of age, it becomes difficult to determine whether a baby was born with CMV or acquired the infection after birth. Congenital CMV can cause long-term health concerns and hearing loss, while an infection acquired after birth (known as postnatal CMV) usually does not.

Missed the 21-day window? If a urine sample was not collected within 21 days of birth, the remaining screening option is a retrospective test on the newborn dried blood spot. The Wisconsin State Laboratory of Hygiene securely stores residual dried blood spot specimens for up to one year and can release them for diagnostic investigation.

To learn more about dried blood spot screening for CMV, contact Kaitlin.Tolliver@dhs.wisconsin.gov

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

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

• Ongoing monitoring for new signs and symptoms, especially hearing loss
• Birth to 3 to support healthy development
• Management of current signs and symptoms
• Family support