You have accessThe ASHA LeaderAll Ears on Audiology1 Jan 2017

What to Know About Advances in CMV Detection, Prevention

Research sheds new light on detection and treatment of congenital cytomegalovirus, but awareness of the hearing-loss-related infection lags.

    Recent advances in research have improved the accuracy and cost-effectiveness of detection and treatment methods for babies born with congenital cytomegalovirus (CMV), a significant cause of permanent childhood hearing loss.

    Approximately one in 150 babies is born with congenital CMV infection in the United States, according to the Centers for Disease Control and Prevention, and congenital CMV infection contributes to permanent disabilities including hearing loss, vision loss, cerebral palsy and/or cognitive impairment in thousands of children born each year.

    Congenital CMV is the most common condition in the Recommended Uniform Screening Panel for newborns. CMV-related disabilities among infants and young children also occur more often than other more well-known diseases, such as Down syndrome, fetal alcohol syndrome or spina bifida (see sources).

    A previous challenge for newborn screening has been the lack of a rapid and relatively inexpensive test for congenital CMV infection. CMV-related sensorineural hearing loss (SNHL) is second only to genetic causes of hearing loss both at birth and during the early years of life. SNHL following congenital CMV may be present at birth or occur later (late onset) in childhood and early adolescence. Children with SNHL following congenital CMV may also have further worsening or progression of their losses (see sources).

    It is important that infants with congenital CMV have early and more frequent audiological evaluations to assess possible changes in their hearing status so that appropriate interventions may be implemented to minimize the impact of their hearing loss. To help accomplish this, audiologists should be aware of the latest research surrounding CMV, and how educational and preventive measures can help parents be more informed of and prepared for the risks.

    It is important that infants with congenital CMV have early and more frequent audiological evaluations to assess possible changes in their hearing status so that appropriate interventions may be implemented to minimize the impact of their hearing loss.

    Diagnosing congenital CMV

    Collection and testing for CMV in saliva and/or urine within the first three weeks of life is the only way to distinguish congenital CMV from postnatal CMV infection. Dried blood spot (DBS) specimens may also be used to identify congenital CMV, but because the sensitivity of DBS testing is low (less than 40 percent), a negative result is inconclusive for diagnosing congenital CMV (see sources).

    Symptoms of congenital CMV infection include petechial rash, purpuric rash, hepatomegaly, splenomegaly, jaundice with direct bilirubin of 3 mg/dL or greater, thrombocytopenia, intracranial calcifications, unexplained neurologic/CNS abnormalities (for example, microcephaly, seizures, and focal or generalized neurologic deficits) or chorioretinitis. However, many congenital CMV infections are asymptomatic, so if there is no early screening for CMV, these infections go undetected and unidentified. As a result, they can contribute to SNHL.

    The 2007 Statement by the Joint Committee on Infant Hearing recommended that infants with confirmed hearing loss and an uncertain etiology following an initial medical evaluation should have an expanded evaluation that includes testing for CMV. However, by the time permanent hearing loss is confirmed by a diagnostic audiologic evaluation and the initial medical evaluation is completed, it is too late to confirm congenital CMV.

    Research advances

    The CMV and Hearing Multicenter Screening (CHIMES) Study (2007–2012), funded by the National Institute on Deafness and Other Communication Disorders, identified a rapid, highly sensitive method for detecting CMV in saliva. This advance could make large-scale newborn CMV screening possible. The ease of saliva collection also makes this screening method practical.

    Another recent study has shown that both targeted CMV screening (after a baby fails the newborn hearing screen) and universal CMV screening are cost-effective. Another study shows that when children with symptomatic congenital CMV received the drug valganciclovir in the first month of life for six months, their hearing remained stable or improved for the better ear in the first 24 months of life (see sources).

    Further follow-up is necessary to evaluate whether valganciclovir has a sustained protective effect for hearing over time. More studies are also needed to determine whether antiviral therapies will have a similar effect on infants with asymptomatic congenital CMV infection and SNHL.

    Meanwhile, several clinical trials are evaluating use of valganciclovir in infants with asymptomatic congenital CMV infection with only isolated hearing loss at birth and in asymptomatic infants with no hearing loss at birth. These data will provide more information about antiviral therapies’ ability to lessen the virus’ effects, including hearing loss.

    Getting the message out

    In spite of all the recent scientific advances, less than a quarter of women of childbearing age have heard of CMV, and even fewer have accurate information about CMV. A recently published report suggests the number of women who know about CMV may be even lower—less than 10 percent.

    Without a vaccine to prevent CMV, we need to provide women with information about CMV and ways to possibly lower their risk of CMV infection. Because CMV is often spread through saliva and urine, prevention messaging should emphasize behaviors—such as not sharing food or drink with young children, not kissing young children on the mouth, and frequently washing hands. These types of precautions could keep mothers from becoming infected with CMV during pregnancy (see sources).

    Increased awareness of CMV among some parents has led to the formation of the nonprofit National CMV Foundation to promote prevention of congenital CMV. Parental advocacy also resulted in Utah’s 2013 passing of the first U.S. law to provide education and prevention messages about CMV to women and to mandate testing for congenital CMV in infants who do not pass their newborn hearing screen.

    In spite of all the recent scientific advances, less than a quarter of women of childbearing age have heard of CMV, and even fewer have accurate information about CMV.

    Because of this legislation, not only are infants with congenital CMV identified, but follow-up rates to audiological services for infants who failed the newborn hearing screen have significantly improved. Connecticut and Illinois also have passed similar legislation to test infants who do not pass their newborn hearing screen for congenital CMV. In addition, Texas, Hawaii and Tennessee have passed legislation to provide CMV education and prevention messaging for women of childbearing age.

    With parents in other states exploring similar legislation, hospitals around the U.S. are beginning to implement CMV screening for newborns who do not pass their hearing screening and are identifying infants with congenital CMV.

    Given congenital CMV infection’s significance as a public health problem, all women need to receive CMV education and prevention messages. This knowledge is key to protecting their infants from congenital CMV infection.

    Hearing Screening Advised for Zika-Exposed Infants

    All infants born to mothers who contracted the Zika virus during pregnancy should have a standard newborn hearing screening as part of a larger initial evaluation, according to recommendations from the Centers for Disease Control and Prevention (CDC).

    The recommendations come as part of the CDC’s wider Zika prevention and treatment plan.

    The CDC also recommends infants who show “laboratory evidence” of congential Zika virus infection and present with symptoms of congenital Zika syndrome should have their hearing assessed via auditory brainstem response (ABR) before the age of 1 month. But the risk of late-onset or progressive hearing loss after infants with Zika pass a normal hearing screening is still unknown, and the CDC says they should be retested through ABR during a follow-up at 4–6 months and referred to an audiologist if hearing results are abnormal.

    The CDC also recommends that providers “refer infants who (a) passed an initial ABR and (b) did not have an ABR at age 4–6 months for behavioral audiologic diagnostic testing at age 9 months or sooner for any hearing concerns.”


    • Boppana S. B., Ross S. A., Novak Z., Shimamura M., Tolan R. W., Palmer A. L., … Fowler K. B. (2010). Dried blood spot real-time polymerase chain reaction assays to screen newborns for congenital cytomegalovirus infection.JAMA, 303(14), 1,375–1,382.
    • Boppana S. B., Ross S. A., Shimamura M., Palmer A. L., Ahmed A., Michaels M. G., … Fowler K. B. (2011). Saliva polymerase-chain-reaction assay for cytomegalovirus screening in newborns.New England Journal of Medicine, 364(22), 2,111–2,118.
    • Cannon M. J. (2009). Congenital cytomegalovirus (CMV) epidemiology and awareness.Journal of Clinical Virology, 4, S6–10.
    • Dahle A. J., Fowler K. B., Wright J. D., Boppana S. B., Britt W. J., & Pass R. F. (2000). Longitudinal investigation of hearing disorders in children with congenital cytomegalovirus.Journal of the American Academy of Audiology, 11(5), 283–290.
    • Doutre S. M., Barrett T. S., Greenlee J., & White K. R. (2016). Losing ground: Awareness of congenital cytomegalovirus in the United States.Journal of Early Hearing Detection and Intervention, 1(2), 39–48.
    • Fowler K. B., & Boppana S. B. (2006). Congenital cytomegalovirus (CMV) infection and hearing deficit.Journal of Clinical Virology, 35(2), 226–231.
    • Fowler K. B., Dahle A. J., Boppana S. B., & Pass R. F. (1999). Newborn hearing screening: Will children with hearing loss due to congenital cytomegalovirus infection be missed.Journal of Pediatrics, 135(1), 60–64.
    • Fowler K. B., McCollister F. P., Dahle A. J., Boppana S., Britt W. J., & Pass R. F. (1997). Progressive and fluctuating sensorineural hearing loss in children with asymptomatic congenital cytomegalovirus infection.Journal of Pediatrics, 130(4), 624–630.
    • Gantt S., Dionne F., Kozak F. K., Goshen O., Goldfarb D. M., Park A. H., … Fowler K. (2016). Cost-effectiveness of universal and targeted newborn screening for congenital cytomegalovirus infection.JAMA Pediatrics. Advance online publication. doi:10.1001/jamapediatrics.2016.2016
    • Goderis J., De Leenheer E., Smets K., Van Hoecke H., Keymeulen A., & Dhooge I. (2014). Hearing loss and congenital CMV infection: A systematic review.Pediatrics, 134(5), 972–982.
    • Joint Committee on Infant Hearing. (2007). Year 2007 position statement: Principles and guidelines for early hearing detection and intervention programs.Pediatrics, 120(4), 898–921.
    • Kimberlin D. W., Jester P. M., Sanchez P. J., Ahmed A., Arav-Boger R., Michaels M. G., … Whitley R. J. (2015). Valganciclovir for symptomatic congenital cytomegalovirus disease.New England Journal of Medicine, 372(10), 933–943.
    • Morton C. C., & Nance W. E. (2006). Newborn hearing screening — a silent revolution.New England Journal of Medicine, 354(20), 2,151–2,164.
    • Picone O., Vauloup-Fellous C., Cordier A. G., Parent Du Chatelet I., Senat M. V., Frydman R., & Grangeot-Keros L. (2009). A 2-year study on cytomegalovirus infection during pregnancy in a French hospital.BJOG, 116(6), 818–823.
    • Revello M. G., Tibaldi C., Masuelli G., Frisina V., Sacchi A., Furione M., … Todros T. (2015). Prevention of primary cytomegalovirus infection in pregnancy.EBioMedicine, 2(9), 1,205–1,210.
    • Vauloup-Fellous C., Picone O., Cordier A. G., Parent-du-Chatelet I., Senat M. V., Frydman R., & Grangeot-Keros L. (2009). Does hygiene counseling have an impact on the rate of CMV primary infection during pregnancy? Results of a 3-year prospective study in a French hospital.Journal of Clinical Virology, 46 Suppl 4, S49–53.

    Author Notes

    Karen B. Fowler, DrPH, is a professor in the infectious diseases division of the Department of Pediatrics at the University of Alabama at Birmingham. Her research focuses on the epidemiology of maternal and congenital CMV infections and sensorineural hearing loss in children.

    Shannon A. Ross, MD, is an associate professor in the infectious diseases division of the Department of Pediatrics at the University of Alabama at Birmingham. Her research focuses on virological characteristics of children with congenital CMV infection and identification of markers of outcome in congenital CMV.

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