Cytomegalovirus (CMV) is a beta herpes virus that occurs worldwide and humans are the only source of human CMV.
In developed countries, more than half the population carry CMV virus by the time they reach adulthood and this figure is much higher in developing countries.
Most people who acquire the virus after birth experience few or no symptoms.
Cytomegalovirus remains latent in the host for their lifetime after primary infection, and may become active again (reactivation) particularly during times of compromised immunity, including pregnancy.
A person can also have another infection with a different strain of the CMV virus.
Congenital CMV (cCMV)
If an unborn baby is infected with CMV, some of these babies may develop serious health problems such as hearing loss, developmental delay or learning problems. Congenital CMV is the most common infective cause of congenital hearing loss.
Infection with CMV during pregnancy may also lead to stillbirth or infant death.
CMV infection can spread in different ways. The virus can be passed from person-to-person, usually through close contact with saliva, breast milk, urine or other body fluid, or through sexual contact with someone with the infection.
Women who become infected with CMV while pregnant may pass the virus to their unborn child.
Babies can also become infected during delivery and from breast milk. Babies who acquire CMV intrapartum, or from their mother's milk, usually have no acute illness, and these infections are not known to cause the central nervous system and sensory disabilities associated with congenital infection. Breastfeeding can therefore be encouraged as it offers many important benefits to mothers and babies.
CMV can also be transmitted during blood transfusions and organ transplants.
A person can have a primary infection (an infection with CMV for the first time), or a return of a previous CMV infection (reactivation), or may have another infection with a different strain (type) of the virus.
The virus is often shed for months in urine or saliva following infection in healthy children and adults.
Infants and immune suppressed adults can shed the virus for months to years following infection or reactivation of infection.
3 to 12 weeks.
Diagnosis in infants is made by growing the virus, usually from urine.
Diagnosis in adults is more complicated and usually requires growing the virus, blood tests or PCR (polymerase chain reaction) tests in a pathology laboratory.
Routine serological screening for CMV in pregnancy is not recommended, as past infection with CMV does not mean complete protection against reinfection or congenital CMV.
Pre-pregnancy or early pregnancy screening may be considered for women who have frequent contact with large numbers of very young children (eg childcare workers) as per the NHMRC endorsed April 2019 recommendations.
The need for screening for CMV should be a discussion between healthcare providers and patients on an individual basis.
Serological and virological testing for CMV should be performed when a pregnant woman develops an illness, typically fever, fatigue, and headache, not attributable to another specific infection, or when imaging findings (ultrasound or MRI) are suggestive of fetal cytomegalovirus infection.
Antiviral medications may be used to treat those infected, including babies.
When congenital CMV infection is suspected on the basis of maternal serology or fetal ultrasound abnormalities, a referral to a maternal fetal medicine specialist, or specialist with expertise in perinatal infections is recommended.
There is currently no effective vaccine to prevent CMV infection.
Exclusion from childcare, preschool, school or work is not necessary.
Pregnant women can reduce their risk of being infected with CMV if they:
Do not share food, drinks, or utensils used by children (under the age of 3 years).
Do not share a toothbrush with a young child.
Do not put a child’s dummy/soother in their mouth.
Avoid contact with saliva when kissing a child (“kiss on the forehead not on the lips”).
Thoroughly wash hands with soap and water for 15-20 seconds, especially after changing nappies or feeding a young child or wiping a young child’s nose or saliva.
Clean toys, countertops and other surfaces that come into contact with children’s urine or saliva with a simple detergent and water.
Use of the information and data contained within this site or these pages is at your sole risk.
If you rely on the information on this site you are responsible for ensuring by independent verification its accuracy, currency or completeness.
This site includes links to other websites operated by community, business and government.
These linked websites will have their own terms and conditions of use and you should familiarise yourself with these.
All linked websites are linked 'as is' and the Government of South Australia:
does not sponsor, endorse or necessarily approve of any material on websites linked from or to this Site;
does not make any warranties or representations regarding the quality, accuracy, merchantability or fitness for purpose of any material on websites linked from or to this Site;
does not make any warranties or representations that material on other websites to which this site is linked does not infringe the intellectual property rights of any person anywhere in the world; and
does not authorise the infringement of any intellectual property rights contained in material in other websites by linking this site to those other websites.
If you use automatic language translation services in connection with this site you do so at your own risk.
The information and data on this site is subject to change without notice. The Government of South Australia may revise this disclaimer at any time by updating this posting.
The Government of South Australia, its agents, instrumentalities, officers and employees:
make no representations, express or implied, as to the accuracy of the information and data contained on this site
make no representations, express or implied, as to the accuracy or usefulness of any translation of the information on this site or any linked website into another language
make no representations as to the availability of the site and the availability of websites linked from or to the site
accept no liability however arising for any loss resulting from the use of the site and any information and data or reliance placed on it (including translated information and data)
make no representations, either expressed or implied, as to the suitability of the said information and data for any particular purpose
accepts no liability for any interference with or damage to a user's computer, software or data occurring in connection with or relating to this Site or its use or any website linked to this site
do not represent or warrant that applications or payments initiated through this site will in fact be received or made to the intended recipient. Users are advised to confirm the application or payment by other means.