Mother and baby cytomegalovirus screening important to prevent consequences

By Dr. Ananya Mandal, MDJun 19 2011

According to health experts, pregnant women and newborns should be screened for a virus that causes brain damage and deafness. The study that appeared in the latest issue of The Medical Journal of Australia yesterday says hundreds of cases of cytomegalovirus (CMV) are likely being missed each year in Australia because of a lack of screening, denying babies treatment for the condition.

A virologist with the University of NSW, Professor William Rawlinson, says a 10-year surveillance project between 1999 and 2009 shows that while Australia is estimated to have about 1,800 cases a year, only five to 25 are being diagnosed. Over the decade-long study, doctors reported a total of 363 cases to the surveillance project team. While 90 per cent had symptoms of the virus, only 15 of the babies, or 8 per cent, were given antiviral treatment.

CMV is a common viral infection that causes flu-like or no symptoms in healthy people. But it may lead to other problems for pregnant women, resulting in severe damage to their babies' brains and livers, with symptoms that can include an enlarged liver, jaundice, hearing loss, progressive visual loss, convulsions and mental retardation. In severe cases the virus can also be fatal.

The experts explain that most infected babies will present as well and not exhibit any symptoms at birth; about 13 per cent or 240 of the 1,800 infected each year will develop permanent problems. If the condition is detected shortly after birth, babies can be given antiviral treatments within their first 30 days of life or hearing aids to improve their development thereafter.

The doctors say that although newborns are given routine hearing tests in most states, those found to have problems are not screened for CMV - an important gap that should be resolved. “Neonatal hearing screening is cost-effective and allows for early intervention with hearing aids and education, which can result in functional language improvements…The cost-effectiveness of incorporating CMV screening into this algorithm urgently needs to be determined,” they write. “Children identified with SNHL (sensorineural hearing loss) are not currently routinely screened for CMV in Australia and this is arguably an important gap within the program… Neonatal hearing screening is cost-effective and allows for early intervention with hearing aids and education, which can result in functional language improvements,” Prof Rawlinson and his team of researchers wrote in their paper.

A vaccine for CMV is being tested in the US and Europe and treatments for pregnant women are being investigated. Professor William Rawlinson, a senior medical virologist at the University of NSW who led the research, said CMV was under-diagnosed, infrequently treated and often manifested itself as isolated hearing loss.