Lower your risk

Young children, especially toddlers under 3 in daycare, often carry CMV in their saliva and urine for months, even when they seem well. These everyday habits lower your risk, which matters most if you are pregnant or planning to be.

What CMV is

Cytomegalovirus (CMV), pronounced sy-toe-MEG-a-low-vy-rus, is a common virus in the herpesvirus family. More than half of adults have had it by age 40, and nearly 1 in 3 children catch it before age 5. Once you have CMV, it stays in your body for life, usually inactive and without causing problems.

CMV spreads through contact with body fluids, such as saliva, urine, blood, tears, semen, or breast milk.

Most healthy adults and children who catch CMV have no symptoms. When symptoms do appear, they are usually mild and feel like a cold:

• Feeling very tired
• Mild fever
• Sore throat
• Swollen glands (lymph nodes)
• Muscle aches

Who is at risk

CMV is mild for most people, but two groups have a higher risk of serious problems.

CMV and pregnancy

When a baby is born with CMV, it is called congenital CMV (cCMV). Most of these babies grow up healthy. But some will have long-term health problems. CMV is the top cause of childhood hearing loss that is not passed down through genes.

CMV by the numbers

Testing during pregnancy

Routine CMV testing is not recommended for all pregnant people. Major medical groups in the United States, including the CDC and the American College of Obstetricians and Gynecologists, advise against it. If you are worried, talk with your provider about whether testing is right for you.

When testing may be done

• You have symptoms during pregnancy, such as an unexplained fever, strong tiredness, or swollen glands.
• A routine ultrasound shows signs that can be linked to CMV.
• You have a known exposure, or you ask for testing after talking through the risks with your provider. This is more common for people who work in childcare or have a toddler at home.

How the test works

A blood test looks for antibodies, the proteins your body makes to fight a virus. One test shows whether you have ever had CMV. Another looks for signs of a recent or current infection. If that one is positive, a follow-up test can estimate whether the infection happened in the last 3 to 4 months or long ago.

Why routine screening is not recommended

• The results are hard to read. A blood test can show a recent infection, but it cannot tell whether the virus will reach the baby or cause harm.
• Past infection does not fully protect you. CMV can become active again, or a new strain can infect you during pregnancy. The risk to the baby is lower than with a first infection, but it is not zero.
• Prevention matters most. There is no CMV vaccine yet, and antiviral treatment during pregnancy is mostly used by specialists or in clinical trials. That is why health agencies focus on hygiene habits for all pregnant people, whatever their test results.

Testing your newborn

Testing a newborn for CMV is quick, painless, and very accurate. It is usually done when a baby fails the hospital hearing test or shows signs of infection at birth.

The test must be done within 21 days of birth. A test in this window shows whether the baby got CMV during pregnancy. If your baby fails a newborn hearing test or shows signs of infection, ask for a CMV test right away.

How newborn testing works

1. A provider collects a sample

   They gently swab the inside of the baby's cheek for saliva, or collect a small urine sample.

2. A lab tests the sample

   A test called PCR looks for the virus.

3. You get results and next steps

   If the test finds CMV, your provider will talk with you about treatment and support.

Babies can also get CMV after birth through close contact or breast milk. This is called postnatal CMV, and it does not carry the same risk of serious, long-term problems.

Treatment and support

Finding CMV early opens the door to treatment and support that can protect your baby's development.

Antiviral medicine

For babies born with signs of CMV, antiviral medicine started in the first month of life can protect hearing and development. Starting early makes a big difference.

New Jersey Early Intervention System

New Jersey offers support for babies and toddlers who qualify, including physical therapy, speech therapy, and regular hearing checks.

CMV in childcare and schools

Children with CMV do not need to stay home from childcare or school unless they have a fever. Up to 70% of healthy toddlers carry CMV off and on without symptoms, so keeping one child home does not protect anyone. Good hygiene habits protect staff and other children.

For help deciding when to keep a sick child home, contact your local health department.

New Jersey's CMV awareness law

CMV is the most common viral infection babies are born with in the United States, yet surveys show more than 90% of people have never heard of it. New Jersey's law (P.L. 2021, c.413) directs the Department of Health to run a statewide awareness campaign and keep education materials in English and Spanish.