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Medical Conditions

Cytomegalovirus (CMV) Infection

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What is cytomegalovirus infection?

A viral infection common in children. Up to 70% of normal children aged 1 to 3 years in group care settings excrete cytomegalovirus (CMV).

What are the signs or symptoms?

  • Generally no symptoms in young children.

  • Older children and adults may have a generalized illness with fever. Sometimes the liver or spleen may become enlarged.

What are the incubation and contagious periods?

Probably several weeks to months. Once a person is infected, the virus is shed intermittently in the urine and saliva for the rest of that person’s life.

How is it spread?

  • Person-to-person contact with blood, saliva, urine, human (breast) milk, and other secretions from infected people

  • Mother to baby before, during, and after birth

  • Blood transfusions from an infected person

  • During kissing and sexual activities

How do you control it?

  • Attention to proper hand-hygiene technique at all the times listed in Chapter 2. This is especially important for women of childbearing age who work with young children. Avoid exchange of saliva directly or via objects and wash hands and objects carefully after contact with urine.

  • Do not kiss children on the lips or allow them to put their fingers or hands in another person’s mouth.

  • Do not share cups or eating utensils.

What are the roles of the teacher/caregiver and the family?

  • Use good hand-hygiene technique at all the times listed in Chapter 2.

  • Review Standard Precautions, particularly hand hygiene, especially for women of childbearing age who work with or have their own children younger than 3 years who participate in group care settings.

  • Women of childbearing age who have any contact with groups of children or have their own children younger than 3 years who participate in group care settings should discuss their risk of CMV exposure with their health care providers. Although most women are already immune to some strains of CMV, the potential consequences to the fetus exposed to CMV in nonimmune pregnant women can be very serious. Risk reduction measures include conscientious hand washing. Staff members who care for children should consider taking care of older children or working in an administrative role during pregnancy. Programs should inform these women about the risk to their unborn child if they become pregnant, urge them to discuss this risk with their health care provider, and have them sign a document indicating their understanding of this risk.

Exclude from group setting?

No, unless

  • The child is unable to participate and staff members determine they cannot care for the child without compromising their ability to care for the health and safety of the other children in the group.

  • The child meets other exclusion criteria.

Readmit to group setting?

Yes, when all the following criteria are met:

When exclusion criteria are resolved, the child is able to participate, and staff members determine they can care for the child without compromising their ability to care for the health and safety of the other children in the group


  • Cytomegalovirus is the most common viral infection that babies are born with, affecting 0.5% to 1.0% of all births. Most infected newborns do not have any illness or disability. However, 10% to 20% of infected newborns have sensorineural hearing loss, developmental disabilities, cerebral palsy, or vision disturbances.

  • Individuals remain infectious as long as the virus is in body secretions, most commonly in urine and saliva, but also in the blood. Shedding of CMV can occur for months or years after the initial infection, on and off indefinitely. Exposure to the virus will occur. Among teens and adults, CMV is spread person-to-person by exchange of saliva or during sexual and intimate exposures. Almost all people will eventually be infected, but most people will never know it because they will not experience any illness.

  • Because this virus is so common in child care settings, exclusion of a CMV-infected child to reduce disease transmission has no benefit. The risk of CMV exposure is greatest in settings that care for children who are younger than 3 years. Testing young children for excretion of the virus or performing CMV antibody tests for young children because they are in a group care setting is not appropriate because infection with the virus is so prevalent and easily shared. This age group has frequent runny noses, frequently mouths objects or drools, and touches many surfaces, including toys and furnishings. They need diapering or toileting assistance.

  • Hand hygiene substantially reduces the spread of infection. Nurses who practice conscientious hand hygiene when caring for children who are shedding CMV can reduce their risk of getting CMV infection to the level experienced in the general community. Unlike child care, nurses work in settings where one adult cares for one child at a time.

  • Cytomegalovirus exposure risk during pregnancy: Although most adults have their first CMV infection during childhood and are immune to the strains of CMV that have infected them, a pregnant woman who works with infants and toddlers or who is a mother with a child in child care is at increased risk of having a CMV infection during her pregnancy and infecting her fetus. This could be her first CMV infection or an infection with a different strain of CMV than she previously experienced.

    • To alert health professionals responsible for the health assessment of staff members of childbearing age about the need of their patient to be counseled about CMV risk, early education/child care center directors/ administrators should be sure CMV risk assessment and counseling are items on the staff health assessment form. In addition, it may be helpful for directors/administrators to attach this Quick Reference Sheet and the Fifth Disease (Human Parvovirus B19) Quick Reference Sheet to the note at the end of this sheet to help health care providers review with their patient the increased risk of exposure to the unborn child if the woman is infected during her pregnancy. Health care providers are not necessarily aware of the increased exposure to these viruses for women who work with young children in child care settings.

    • A blood test for CMV antibodies will show whether a woman has some immunity or has never had a CMV infection. The value of such testing should be discussed by the woman with her health professional. While having had CMV in the past reduces the risk of infection of an unborn child, infection during pregnancy with a different strain of CMV than the mother had previously is a possibility.

    • Successful litigation in 2015 against a child care center operator was brought by a teacher/caregiver who was pregnant while she cared for infant and toddler groups and gave birth to a severely disabled child because of a CMV infection during her pregnancy. The child care center operator failed to provide information about the increased risk of exposure in pregnancy to CMV and failed to urge employees of childbearing age to discuss this risk with their health care providers.

Dear Health Professional:

Your patient works in a setting where she has contact with young children in groups. Human parvovirus B19 and cytomegalovirus (CMV) occur commonly and are often asymptomatic among young children. Exposure of a woman who lacks immunity to human parvovirus B19 and CMV during pregnancy poses some risk to her fetus. Please discuss with your patient her childbearing intentions and whether she might want to consider these risk-reduction measures when she might become pregnant:

  • Conscientious hand washing after any contact with saliva, urine, or blood

  • Care of children who are older than 3 years

  • Working in a role other than direct care of young children

About Serologic Testing

Because different strains of CMV circulate among young children, especially those in group care, a serologic test for CMV informs about risk but does not completely guarantee immunity from exposure to novel strains. However, a serologic test for human parvovirus B19 is a reliable indicator of immunity.

Listing of resources does not imply an endorsement by the American Academy of Pediatrics (AAP). The AAP is not responsible for the content of external resources. Information was current at the time of publication.

The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

Quick Reference Sheet from Managing Infectious Diseases in Child Care and Schools: A Quick Reference Guide.

© 2017 American Academy of Pediatrics. All rights reserved.

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