Telethon Kids Institute researchers are working with Perth Children’s Hospital and other experts across the country to get ahead of a sneaky virus few mums or even health professionals have heard of, despite it being one of the biggest causes of permanent hearing loss in children every year.
Cytomegalovirus (CMV) is so common and so low-key that it circulates virtually unnoticed in our community. Most adults have had it, but the majority remain asymptomatic or experience symptoms that feel just like a cold or flu.
For some expectant mums, though, CMV presents a hidden risk to their baby that they’ve probably never heard of – one that can cause permanent hearing loss, intellectual disability or cerebral palsy.
Around two-thirds of women will have been infected with CMV by the time they become pregnant. Once a person is infected, the virus remains ‘viable’ but inactive in the body, but for a small number of pregnant women, it can reactivate or be acquired unknowingly, placing their baby at risk.
Associate Professor Asha Bowen
According to paediatric infectious diseases researcher and clinician Associate Professor Asha Bowen, the best window for congenital CMV diagnosis is within the first three weeks of life, but because it’s not well-recognised and there’s no coordinated screening program in place in Australia, cases are frequently missed.
“The first most parents know something is wrong is when their child starts losing their hearing in toddlerhood or the early primary years,” Associate Professor Bowen said.
“By then it’s often too late to diagnose the cause, so they never find out the reason for their child’s condition.”
Keen to improve diagnosis rates and give affected children and families the support they need, Associate Professor Bowen and a team of researchers – led by Perth Children’s Hospital (PCH) ear nose and throat registrar and University of Western Australia PhD student Dr Allison Reid – are pushing for targeted screening to be introduced across the country. The change would see every Australian baby who fails their newborn hearing assessment – a tell-tale sign of congenital CMV – screened for the virus via a simple saliva or urine test.
Congenital CMV is having a profound impact on the lives of hundreds of Australian children every year, but most cases currently go undiagnosed. - Associate Professor Bowen
“The sooner we can pick this virus up the better – early diagnosis is crucial so we can get kids into routine follow-up and support.”
Dr Reid, Associate Professor Bowen, Associate Professor Chris Brennan-Jones (Telethon Kids and Curtin University) and Associate Professor Jafri Kuthubutheen (PCH and UWA) published a paper in the Medical Journal of Australia this year arguing for targeted screening and are currently working with a wider team of researchers – led by Dr Reid – to test the approach via a two-year trial at PCH.
Although it still has a few months to run, the trial – assessing the health and economic impact of offering CMV testing to any newborn who fails their hearing test – is already making a difference to children’s lives.
“Early intervention can change the trajectory of a child,” Associate Professor Bowen said. “Apart from paving the way for prompt audiology, speech and language support, early diagnosis also means we can get the child onto a path for cochlear implant, if appropriate, and assess and monitor them for other potential impacts that we otherwise may not go looking for.”
In another key move to tackle the impacts of the virus, Associate Professor Bowen is leading a group of researchers – including Professor Cheryl Jones (University of Sydney) and Dr Hayley Smithers-Sheedy (Cerebral Palsy Alliance Research Institute, University of Sydney) – who have established a confidential register to identify and follow confirmed cases of congenital CMV.
The Australasian Congenital Cytomegalovirus Register (ACMVR) is a database of clinical information about children with confirmed congenital CMV born or living across Australia and New Zealand.
Designed to track trends over time, identify risk groups, and lay the groundwork for evaluation of future intervention programs, the register allows researchers to observe the incidence of congenital CMV infection while collecting valuable evidence and data about outcomes for affected babies throughout childhood and beyond.
Associate Professor Bowen said the ACMVR would help researchers better understand congenital CMV.
We know this virus affects each baby differently, and there is still much to learn about the long-term outcomes of congenital infection.
With no treatment or proven therapy currently available to treat a foetal CMV infection, Associate Professor Bowen said the multi-pronged approach of building an argument for national, standardised newborn screening of CMV, getting affected babies into early intervention programs, and following up confirmed cases long-term offered the best chance of improving outcomes for children and families.
“Thanks to the work we're doing across multiple disciplines here at Telethon Kids – including infectious diseases, child disability, and paediatric rehabilitation – and in collaboration with our colleagues at PCH, University of Sydney, UWA, Curtin and elsewhere, we’re more hopeful than we’ve been in a while that we can provide families affected by this virus with the answers and support they deserve,” she said.
Quick facts
- Congenital CMV occurs in ½ to 1% of the approximately 300,000 babies born in Australia every year –around 3,000 cases every year.
- About 90% of those babies who get congenital CMV will remain asymptomatic, but for the 10% who are more seriously affected – around 300 babies a year – it can cause progressive and permanent hearing loss and, for some, intellectual disability, or cerebral palsy