Information
What is Congenital CMV?
CMV or cytomegalovirus is a common virus that can infect people of all ages. In healthy adults it causes almost no signs or symptoms. However, CMV can pose serious problems if women becomes infected during pregnancy and it passes through the placenta to affect the baby. This is known as congenital cytomegalovirus or cCMV.
Cytomegalovirus is the most common infectious cause of birth defects and congenital CMV infection is estimated to be the main cause of non-inherited sensorineural hearing loss.
Around one in 200 children born in Europe have congenital CMV infection, but most of them are never diagnosed with the condition, and consequently do not get access to treatment, if they need it.
In some countries antenatal or postnatal screening for this infection was already established. But most countries do not undertake routine screening for this infection, so the only children who are diagnosed are either those with symptoms at birth, or those who fail the new born hearing screening test.
How is CMV spread?
CMV is mainly spread through close contact with someone who already has CMV.
It can be passed on through sexual contact and contact with other body fluids including saliva, blood, breast milk, tears, pee and poo.
CMV can only be passed on when it’s “active”. The virus is active when:
- You get CMV for the first time – young children often get CMV for the first time at nursery
- The virus has “re-activated” – because you have a weakened immune system
- You’ve been re-infected – with a different type (strain) of CMV
Pregnant women can pass an “active” CMV infection on to their unborn baby. This is known as congenital CMV.
How can CMV be prevented?
Although clinical trials of CMV vaccines are currently underway, there is no licensed vaccine against CMV at this time. Without a vaccine against CMV, reducing the risks of transmission is the most important thing that we can all do.
There are ways you can reduce the risk of infection whilst you are pregnant. Pregnant women are recommended to take steps to reduce their risk of exposure to CMV and so reduce the risk of their developing baby becoming infected.
Wash your hands after contact with a child’s urine or saliva. Clean your hands after changing a nappy, feeding a child or wiping a child’s nose or mouth.
Wash your hands well for 20 seconds with soap and water. If you do not have access to soap and water, use hand sanitiser. This should be done especially after close contact with young children, changing nappies, blowing noses, feeding a young child, and handling children’s toys, dummies/soothers.
Avoid putting things in your mouth that have just been in a child’s mouth. When possible, try not to share food, cups or cutlery, or put your child’s dummy in your mouth.
Wash any items which may have been in contact with a child’s saliva or urine.
Avoid contact with saliva when kissing a child.
Use simple detergent and water to clean toys, countertops and other surfaces that come into contact with children’s urine, mucous or saliva.
Child care workers who are pregnant or considering pregnancy should pay particular attention to good hand hygiene, especially after changing nappies or assisting with blowing noses or toileting.
My child has been diagnosed with congenital CMV – what does this mean?
If your child has been diagnosed with congenital CMV this means that they have been found to have CMV in their blood, saliva or urine within three weeks of birth. This means that they most likely caught CMV when they were in the womb. Babies born with congenital CMV can have very diverse outcomes and it can be difficult to predict their future progress
The majority of babies born with congenital CMV will not have any symptoms at birth or have any long term problems, however others may experience
- Hearing loss
- Visual loss
- Cerebral palsy
- Feeding difficulties
- Seizures
- Developmental differences
Your baby will have blood tests, a brain scan, eye and hearing checks to assess how CMV is affecting them and to help decide if they need treatment.
What treatment is there for congenital CMV?
Some babies born with congenital CMV do not have any symptoms and do not need any treatment.
Other require treatment with antiviral medication, this can be given through a drip (intravenously) or via mouth depending on the child’s needs. Treatment needs to be started early to be effective. Evidence suggests that the use of a antiviral drug is helpful in reducing the risk of the CMV infection passing from the mother to her baby during pregnancy or to reduce the risk of severe problems in babies that have been infected.
Your doctor will assess your baby to decide if treatment is required. Antiviral treatment has been shown to improve long-term hearing and development outcomes in babies who have symptoms of CMV at birth. Babies on anti-viral treatment require blood tests to check their blood count, liver function and kidney function as these can be affected by anti-viral treatment.
What follow up will my child need?
If your child is born with cCMV they will require regular check ups of their hearing, vision and development especially over the first five years of their life
