Testing for congenital cytomegalovirus (cCMV) at birth using the dried blood spot (DBS) test is a reliable and effective method to identify newborns at risk for long-term developmental challenges, a study has confirmed.
Congenital CMV is a virus passed to infants in the womb and occurs in about one in 200 infants. About 20% of babies with cCMV infection have birth defects or other long-term health problems including hearing loss.
Associate Professor Valerie Sung, paediatrician and principal research fellow at The Centre for Community Child Health (CCCH), said cCMV was the leading infectious cause of childhood sensorineural hearing loss, and Australia was lagging behind in cCMV screening despite robust evidence for targeted screening.
The Centre for Community Child Health is a department of The Royal Children’s Hospital and a research group of Murdoch Children’s Research Institute.
The new study, from the University of Minnesota Medical School, was published in JAMA Network Open.
Researchers said their findings demonstrated that the PCR-based test performed on dried blood spots was just as useful in identifying infants who needed follow-up for their congenital CMV infection as other tests that used urine or saliva.
This was significant because it avoided added time, higher costs, and potential stress for families that came with collecting other types of samples from newborns, they said.
Detected nearly all cases
The researchers said the blood spot method detected more than 90% of symptomatic CMV cases, effectively identifying babies who are most in need of early interventions and ongoing developmental monitoring.
“Babies born with CMV infection, more often than not, do just fine,” said paediatrican Professor Mark Schleiss from the University of Minnesota Medical School. “However, enough infants experience complications – such as hearing loss and developmental delay – that there has long been debate about screening all newborns.”
Prof Schleiss said the study confirmed the wisdom of universal testing and was a testament to the power of parental advocacy, which led to the passage of law in Minnesota as the first American state to screen every newborn for cCMV.
Meanwhile, his team at the University of Minnesota Medical School secured a large National Institutes of Health grant in September 2025 to launch the first study of its kind on how congenital cytomegalovirus (cCMV) impacts child development.
A/Prof Sung described this as a critical and much needed body of work to determine long term outcomes of children with asymptomatic cCMV.
She noted Australia was also trying to do the same through the Australasian Congenital CMV Register supported by the Cerebral Palsy Alliance and Australia’s largest birth cohort GenV.
“Australia is lagging behind in cCMV screening despite the robust evidence for targeted screening – we need to do better,” she said.
A/Prof Sung explained cCMV was not routinely screened for in Victoria and Australia. This meant it was less likely that infants with cCMV would be detected in time to offer potential antiviral treatment.
“Targeted CMV screening using saliva tests in babies who do not pass their newborn hearing check would allow for an early and accurate cCMV diagnosis and could help prevent lifelong disabilities. It should be rolled out nationwide through newborn hearing screening programs,” A/Prof Sung added.
Timely screening was more difficult after mothers and babies were discharged, meaning cases could be missed, she noted.
A study by A/Prof Sung and colleagues, published in the Journal of Paediatrics and Child Health in October 2022, found parents could do a saliva swab of their baby at home and the test was feasible and well received.
Additionally, international guidelines recommended targeted CMV screening of newborns who did not pass hearing checks, she said.
Treatment improves hearing outcomes
The researchers said, in the paper, that cCMV could lead to progressive hearing loss, as well as neurodevelopmental sequelae, including cerebral palsy.
“Two randomised controlled trials suggest treatment within one month post-natally improves hearing and development outcomes in infants with symptomatic cCMV,” they wrote.
The paper suggested targeted screening for cCMV provided families the opportunity to detect and, if appropriate, treat cCMV in the first month of life with antiviral treatment.
Additionally, it fell within the range between cost neutral and cost saving.
The researchers had hoped it would pave the way for testing of cCMV to be added to infant hearing screening programs in Australia.
A mother’s plea
Victorian mother Ms Amity Adley said she believed that screening her son for cCMV as a newborn had changed the course of his life.
“So many medical professionals have called us lucky,” she said. “We met the right person, we asked the right questions, those questions led to a cCMV screen, which led to treatment, which has now led to the thriving, healthy boy I see before me today.
“Every time I look at him, I feel both deep gratitude but also deep sadness because I know how many mothers and babies weren’t given that chance. Outcomes like ours should never rely on luck.
“Targeted cCMV screening has the power to change lives and I’m deeply disappointed that Australia is not moving faster with providing it. It is unjust and unacceptable, and it’s Australian families who will suffer as a result of this inaction.”
