It is one of the most common viral infections, but few people have heard of it.
Cytomegalovirus, or CMV, is a member of the herpes family, which causes a non-specific flu-like illness in healthy adults. Transmitted by contact with saliva, urine or genital secretions, up to 85 per cent of people have been infected with it by the time they're 40.
For most of us, CMV is a minor illness that passes after a few days. In certain people, however, including pregnant women, the effects can be much more severe.
"CMV can cause serious problems for the unborn fetus," says Professor Michael Permezel, president of The Royal Australian and New Zealand College of Obstetricians and Gynaecologists. "The most susceptible to CMV infection are women who have not had it previously - which is about half of all pregnant women."
According to Professor Permezel, of the women who contract CMV during their pregnancy (around 2 per cent), approximately half will have the virus cross the placenta and infect the fetus. Associated problems can include deafness, cerebral palsy, poor eyesight, intellectual disability, an enlarged liver or spleen, and a small head. The role of CMV in stillbirths has also recently been investigated in Australia.
CMV blood tests are usually only offered to women who have a viral illness in pregnancy, or if an ultrasound shows an abnormality in the fetus, but they can be requested. Some studies even recommend immunity to CMV be tested before conception.
Four years ago, Kate Daly was blissfully unaware of CMV. The first sign that something was wrong with one of her twins, William, was when he failed his newborn hearing test.
"I had never heard of CMV before," says Kate. "Emmaline and William were both born with congenital CMV, but thankfully Emmaline is asymptomatic."
William, on the other hand, is deaf. He also has mild cerebral palsy, moderate global developmental delay and severe dyspraxia (motor learning disability).
Kate says the diagnosis of CMV was devastating. "I was anxious and afraid for the first few years because I had no real idea on what I had to accept. I felt lonely and overwhelmed trying to grasp my new life as a parent of a child with multiple disabilities while watching so many around me get on with life. There was also guilt and anger, which often comes hand in hand with grief."
In her search for information and support about CMV, Kate founded the Congenital CMV Association of Australia, and was surprised at how little pregnant women knew about the virus.
"Everyone needs to know that CMV is a common virus and the most common cause of newborn disabilities, but with a few minor changes you can minimise your risk of getting CMV by 50 per cent," says Kate.
"I've always felt very strongly about having missed the opportunity to reduce my risk of contracting CMV in the first place because I wasn't informed."
Women in close contact with children (such as childcare workers or mothers of toddlers) may be at increased risk of infection during pregnancy, because the illness is common in young children.
Professor Permezel says that the most effective preventative measure is handwashing with soap and water after changing nappies, feeding a young child, wiping a young child's nose or dribble and handling children's toys.
"A vaccination against CMV infection would be very beneficial and is currently under development," he says.
June is CMV Awareness Month. For more information go to www.facebook.com/CCMVAustralia.