Summary about Disease
Congenital cytomegalovirus (CMV) infection occurs when a pregnant woman is infected with CMV and passes the virus to her developing baby. CMV is a common virus, and most adults have been infected at some point in their lives, often without knowing it. However, a primary CMV infection during pregnancy can be dangerous for the fetus, leading to a range of health problems. Congenital CMV is a leading cause of birth defects and developmental disabilities.
Symptoms
Many babies with congenital CMV have no symptoms at birth. However, when symptoms are present, they can include:
Premature birth
Low birth weight
Jaundice (yellowing of the skin and eyes)
Enlarged liver and spleen
Microcephaly (small head size)
Seizures
Rash
Hearing loss (can be present at birth or develop later)
Vision problems
Developmental delays
Intellectual disability
Motor problems
Causes
Congenital CMV is caused by the transmission of CMV from a pregnant woman to her fetus. This can happen when the mother experiences a primary CMV infection (first-time infection) during pregnancy, or when she has a reactivation of a previous infection. The risk of transmission is higher during a primary infection. The virus crosses the placenta and infects the developing baby.
Medicine Used
Antiviral medications like valganciclovir or ganciclovir may be used to treat symptomatic infants with congenital CMV, particularly those with central nervous system involvement (e.g., brain abnormalities, hearing loss). Treatment aims to reduce the severity of the infection and improve outcomes.
Is Communicable
Congenital CMV itself is not communicable in the sense that an infected baby can directly transmit it to another person through casual contact after birth (except to the mother). However, the virus is shed in bodily fluids (urine, saliva, breast milk) and can be transmitted to caregivers who are not already immune.
Precautions
Pregnant women can take the following precautions to reduce their risk of CMV infection:
Wash hands frequently with soap and water, especially after changing diapers or feeding young children.
Avoid sharing food, drinks, or utensils with young children.
Clean toys and surfaces that children may have touched.
If working in daycare or healthcare settings, follow strict hygiene protocols.
Consider getting tested for CMV immunity before pregnancy, although this is not a routine screening.
How long does an outbreak last?
CMV infection is typically persistent. While the initial primary infection may resolve, the virus remains dormant in the body for life. It can reactivate and shed in bodily fluids intermittently, even without causing symptoms in the infected person. For infants with congenital CMV, viral shedding can continue for months or years after birth. Therefore, it's not an "outbreak" in the typical sense with a defined start and end, but rather persistent viral shedding.
How is it diagnosed?
Congenital CMV is diagnosed by testing a newborn's blood, saliva, or urine for the presence of CMV within the first 2-3 weeks of life. Testing after this period makes it difficult to determine if the infection was congenital or acquired after birth. Amniocentesis during pregnancy can detect CMV in the amniotic fluid, but this is typically only done if the mother has a confirmed CMV infection during pregnancy and there are concerns about fetal health. Hearing tests and brain imaging (MRI or CT scan) are also often performed to assess the extent of the infection.
Timeline of Symptoms
During Pregnancy: If symptomatic, the mother may experience mild flu-like symptoms, often unnoticed.
At Birth: Some infants show symptoms immediately at birth (e.g., jaundice, rash, low birth weight).
Within First Few Months: Other symptoms, like hearing loss or developmental delays, may not be apparent at birth and can develop over the first few months or years of life. Hearing loss can be progressive.
Long-Term: Some effects of congenital CMV, such as learning disabilities or motor problems, may not become evident until the child is older and reaches developmental milestones.
Important Considerations
Early diagnosis and intervention are crucial for improving outcomes in infants with symptomatic congenital CMV.
Infants diagnosed with congenital CMV should have regular hearing and vision evaluations.
Developmental monitoring is essential to identify and address any developmental delays or learning disabilities.
While antiviral treatment can be beneficial, it does not eliminate the virus and does not guarantee a complete recovery.
Even asymptomatic infants with congenital CMV can develop hearing loss later in life, so ongoing monitoring is important.
Counseling and support for families affected by congenital CMV are essential to help them cope with the challenges of raising a child with this condition.