Experts have advised pregnant women and newborn babies to
routinely screen for a virus that causes hearing loss and intellectual
disabilities in infants.
Cytomegalovirus (CMV) is a common viral infection that
causes flu-like or no symptoms in healthy people. However, it can cause additional
problems for pregnant women, particularly if the infection occurs for the first
time during pregnancy, potentially resulting in hearing loss and intellectual
disability in newborn babies. The prevalence of CMV worldwide at birth is about
0.64 per cent with 10 to 15 per cent of infants displaying symptoms of the
virus at birth.
CMV is greatly under diagnosed, said Professor William Rawlinson of the University of New South Wales and South East Area
Laboratory Services at the Randwick Hospitals Campus.
"Based on a live birth rate of 285,000 per year in Australia, and
a CMV birth prevalence of around 0.64 per cent, the predicted incidence is
about 1,800 infected infants per year, which is substantially more than the
national rates of 5-25 cases per year we have collected through the Australian
Paediatric Surveillance Unit," Prof Rawlinson said.
"Most infected babies will be well. However, about half of
the infants who develop disease will be asymptomatic at birth and are unlikely
to be identified without screening." About 13.5 per cent (240 per year), will
go on to develop permanent problems. In the more severely affected babies who
are identified at birth, CMV can be treated with an antiviral therapy if
treatment starts before 30 days of age," Prof Rawlinson said.
"With an additional estimated 100 cases symptomatic at birth
every year, over 400 children per year may be affected by this disease in Australia, with
no routine newborn screening currently in place," Prof Rawlinson said. "With a
vaccine having been trialled in the US
and Europe, and treatments during pregnancy
being further assessed, we need to continue approaching this problem in
partnership with all the clinical and community stakeholders involved."
Prof Rawlinson and co-authors call for the cost
effectiveness of incorporating congenital CMV screening into neonatal screening
tests to be determined, and the potential benefits, including the opportunity
for doctors to better diagnose pregnant women with the infection, and prescribe
targeted antiviral therapy in infants with hearing loss weighed against issues
of cost and availability of timely CMV testing.
The Medical Journal of Australia is a publication of the
Australian Medical Association.