State’s Universal Newborn Screening for Congenital CMV Shows Promise

Minnesota’s new universal newborn screening program for congenital cytomegalovirus (CMV) identified infants with neurologic abnormalities and those at risk for permanent hearing loss who otherwise might have been missed by routine care or targeted screening, according to data from the state’s health department.

From February 2023, when the program began, to February 2024, 184 cases of congenital CMV infection or disease were identified among 60,115 infants screened using dried blood spot polymerase chain reaction (PCR) testing, the majority of which (n=174) were detected during the first 21 days of life, reported researchers led by Tory Kaye, MPH, of the Minnesota Department of Health in Saint Paul, in the Morbidity and Mortality Weekly Report.

This observed congenital CMV prevalence of 0.29% of live births was somewhat lower than the previously reported estimates of 0.5% among U.S. infants.

Of the total cases, congenital CMV was confirmed in nearly all infants (99%) with diagnostic PCR testing. Later, clinician or laboratory testing identified three additional cases in infants who had a negative dried blood spot screening test.

Minnesota was the first state to implement universal screening for congenital CMV. With targeted screening, only infants who show symptoms or who do not pass their newborn hearing screening are screened for the infection.

“Only a minority of babies with congenital CMV are identified by targeted screening” as opposed to universal screening, Laura Gibson, MD, of the UMass Chan Medical School in Worcester, Massachusetts, told MedPage Today. “We would expect that abnormalities from CMV ‘disease’ would be identifiable by physical exam, but these data suggest that the sickest babies may not appear so at birth and would therefore not be diagnosed without universal screening.”

Screening can be conducted using dried blood spot or saliva testing, Gibson explained, noting that there are pros and cons to different screening approaches. “Dried blood spot screening missed some cases, but almost all identified cases were confirmed to have CMV, while saliva can be the opposite, with all potential cases identified but only a subset confirmed,” she said.

“After consideration of these options, the best screening method for each state or institution may just be the most logistically feasible,” added Gibson, who was not involved with the study.

Universal newborn CMV screening remains controversial because of clinicians’ and parents’ concerns about overtreatment with potent, costly antiviral medications for asymptomatic infants who screen positive. To date, the CDC has not issued a recommendation for or against universal testing.

Of the cases in Minnesota, only 75% of infants underwent all recommended neuroimaging, audiology, and ophthalmology assessments, though most underwent at least one of the three: 91%, 89%, and 80%, respectively.

“We all hope for a higher rate over time, but this number is a helpful benchmark for care in the first year of a statewide universal screening program,” Gibson noted.

On evaluation, 34% of infants with congenital CMV infection had clinical findings, most commonly nonspecific neuroimaging abnormalities, but not all of the findings indicated disease. On newborn hearing screening, 16% received non-passing results and 6% had permanent hearing loss.

Of note, 8.5% of infants with a positive CMV screen received antiviral therapy, suggesting that identifying more infants with CMV infection does not necessarily lead to overtreatment with antivirals, Gibson said.

The CDC recently developed a new case definition for congenital CMV used to define the disease for public health surveillance. Kaye and colleagues incorporated this definition into their analysis.

Although not intended to be used by healthcare providers for clinical diagnosis or management, “it was exciting to see the new congenital CMV case definitions applied to statewide data,” Gibson said. “Other states will benefit from understanding how they affect congenital CMV surveillance, especially where newborn screening legislation and required case reporting are distinct processes.”