Zika’s prevalence could bring awareness to lesser-known CMV virus

CMV sickens more babies than Zika, but doctors don't always mention it to pregnant women.

Many pregnant women may not have heard of cytomegalovirus, or CMV, a common and generally benign virus in adults that can lead to hearing loss and cognitive delays in their babies and even death. Thanks to the widespread attention given to the Zika virus, which can be similarly devastating to fetuses, word may be spreading.

It's still not, however, a given that OB-GYNs will bring it up.

CMV, which causes permanent damage in an estimated 5,000 babies a year, was never mentioned to Glen Burnie mother Alyson Topper, whose daughter Hailey was diagnosed with the virus soon after she was born 15 months ago. There is no vaccine or cure and little proof that catching the highly contagious bug can be easily prevented, but Topper wishes she'd known about it.

Dr. Brenna Hughes, an obstetrician and faculty member at the Duke University School of Medicine and a CMV expert, said, "It disappoints me to say it, but I understand why obstetricians and patients aren't routinely talking about CMV."

Hughes helped craft guidance offered by the American College of Obstetricians and Gynecologists for doctors that says there might not be upside to mentioning a frightening virus when there are few quality studies offering answers about prevention and treatment, though recent research shows extended use of an antiviral may provide some benefit in newborns with symptoms.

The advice, however, doesn't tell doctors not to discuss CMV, which just about everyone catches at some point though it rarely causes harm in healthy adults or children. Hughes said there might be value in warning pregnant women to wash their hands vigorously after changing diapers or wear gloves, for example, since CMV is passed through bodily fluids and infected toddlers don't always appear sick.

Topper said she and her three older children came down with flu-like symptoms while she was pregnant. She now believes that's when she was infected. Had she known about CMV, she wouldn't have shared water bottles with her kids and would have carefully washed her hands after changing each wet diaper.

She now wants all pregnant women to know about CMV so they can at least try to prevent it or understand a diagnosis should they get one.

Topper also believes that more newborns ought to be screened because they don't all immediately show symptoms. Hailey failed a hearing test at the hospital, a common sign that led her to be tested for CMV. Topper got the news a week later from her pediatrician.

Such screening is uncommon; Maryland does not routinely test for any infectious diseases at birth, according to the state Department of Health and Mental Hygiene.

Hailey was put on a drug called Valganciclovir, which a study published last year in the New England Journal of Medicine suggested could lessen the severity of hearing loss and might improve brain growth in newborns born with symptoms of CMV. But it's unknown whether it would improve outcomes for the 10 percent to 15 percent of babies who develop symptoms later in life.

The extent of Hailey's disabilities are not yet clear — CMV comes with a range, from some hearing loss to microcephaly, also a telltale sign of a Zika infection that is characterized by small heads and brains. So far, her eyesight is good and hearing loss is limited to one ear. She's missed important milestones such as rolling over, sitting up and walking, but she's growing and is eager to smile, grab a toy and engage with her family.

She has made progress with help from the Anne Arundel County hearing and occupational therapists who come to Topper's home regularly.

"I feel fortunate because some babies don't survive," Topper said.

"But this is my fourth kid, and I had no idea I had a carrier right there," Topper said, pointing to her 3-year-old son, Sam. "It was such a big shock. We just started Googling CMV like crazy."

While doctors like Hughes worry that pregnant women's "eyes can glaze over" when she lumps in too many medical terms during visits, Topper thought maybe a name would have caught her attention and perhaps made a difference.

About one out of every 150 babies is born with congenital CMV infection, according to the U.S. Centers for Disease Control and Prevention, or more than 30,000 a year. Up to 20 percent, or about 6,000, of them will suffer long-term health problems. (So far, the CDC reports a much smaller number are affected by Zika in the United States: 37 babies born with defects or miscarried by infected mothers.)

The prevalence has other CMV researchers calling for more information for pregnant women given that there is now more evidence that a drug might be helpful if given for six months rather than six weeks. That includes Dr. Ravit Boger, an associate professor of pediatrics at the Johns Hopkins University School of Medicine, who participated in the drug study.

She said the drug is not "the ultimate therapy," but some potential improvement is better than none. If the drug is eventually shown to also aid babies who haven't yet developed symptoms, she said, screening of newborns would likely become more common.

Research also continues. Boger led a team that has found a genetic mutation that may increase susceptibility to CMV infection. The findings published last month in the Proceedings of the National Academy of Sciences suggest one reason some people are more at risk. Boger said someday scientists may be able to identify them and manage their risk.

With Zika still in the news, she hopes there will eventually be funding for development of more treatments for other infections such as CMV. For now, she'd settle for more counseling in the doctors' offices.

"With so much becoming known about Zika during pregnancy, I suspect education for pregnant women about CMV may improve," she said. "That could be one good outcome of Zika."

meredith.cohn@baltsun.com

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