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CMV Testing: Why You Don’t Need Legislation to Make It a Good Idea

August 20, 2019
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CMV is the leading non-genetic cause of sensorineural hearing loss in infancy and childhood. Identification of newborns with congenital CMV infection can improve their outcomes by early intervention programs and/or antiviral treatment.

Cytomegalovirus, or CMV, infects almost everyone at some point in time, and it is one of the most common congenital infections worldwide. While CMV remains latent most of the time in the majority of people, for some, CMV may have a variety of symptoms, ranging from mild to severe.

The biggest problem with CMV arises if a pregnant woman transmits CMV to her unborn baby through the placenta. About one in every 200 babies is born with congenital CMV infection. Of those infected, about 10% will experience symptomatic CMV disease. The most common symptom of CMV in newborns is hearing loss.

While studies have shown that identifying and treating congenital CMV in babies in the first month of age has been linked to improved hearing outcomes, only a few states mandate a test for CMV when a newborn does not pass the hearing screen. Pablo Sánchez, MD, principal investigator in the Center for Perinatal Research at the Abigail Wexner Research Institute and a neonatologist and pediatric infectious diseases specialist at Nationwide Children’s Hospital, suggests this is not something that physicians should rely on legislation to dictate but rather something practitioners and health care professionals should be doing regardless.

“Any baby, infant, or patient who does not pass a hearing test, we as health care professionals should want to know why,” Dr. Sanchez says. “We should not need legislators to tell us to do this. It should be part of medical practice.”

Even before the baby is born and refers on the hearing test, it is possible to determine if a baby will be born with congenital CMV during amniocentesis testing.  Testing a mother for CMV, however, is generally not recommended unless there are symptoms of concern in the fetus. This is because the fetus could get infected even if the mother has had CMV before becoming pregnant. Pregnant women can get CMV for the first time during the pregnancy but they also can get infected again with a different strain of the virus.   

Studies show that antiviral therapy in the first month of age can positively affect the hearing outcomes of infants. Unfortunately, treatment of pregnant women with immune globulin against CMV has not prevented the fetus from becoming infected with CMV. Studies of antiviral treatment of pregnant women to prevent serious infection of the fetus need to be done. 

“It has been said, and I agree, that a CMV vaccine is the number one priority so CMV infection of the fetus can be prevented. Unfortunately, we are not there yet. Several potential CMV vaccines are in early stages of development and study, but it has been a difficult process,” Dr. Sánchez says. 

“Until then, the best way to help mothers prevent CMV infection is to educate them about the virus and on how they can get infected. CMV can be present in all of our body fluids, and we get infected by sharing those body fluids like saliva that contain CMV with others. We often drink from other people’s cups and water bottles, or we don’t wash our hands after diaper changes, and if those fluids contain CMV, we become infected. The only way, however, to know if the fetus was infected with CMV is by testing the baby for CMV before 3 weeks of age, and if there are symptoms of the infection, initiating treatment before a month of age.”

For more information about CMV, visit the Nationwide Children’s infectious disease website or the National CMV Foundation’s website.

In honor of June being Congenital Cytomegalovirus Awareness Month, the 45th episode of Nationwide Children’s PediaCast CME focuses on this topic. The podcast, featuring Dr. Mike Patrick and Dr. Pablo Sánchez, dives into congenital CMV, exploring the cause, diagnosis, treatment and more.

You can listen to the episode wherever podcasts are found.

 

Image credit: Adobe Stock