Cytomegalovirus (CMV) is a very common virus that can infect people of all ages. It is remarkably widespread; in the United States, by the age of 5, nearly 1 in 3 children have already been infected with CMV. By the time they reach 40 years old, over half of adults have contracted this virus.
Once a person becomes infected with CMV, the virus remains in their body for life. It can reactivate at any time, and individuals can also be infected again with different strains of CMV. For most healthy individuals, CMV poses no significant threat, often causing no noticeable symptoms. However, understanding what CMV is, how it spreads, and who is at risk is crucial for public health awareness.
Signs and Symptoms of CMV Infection
The majority of people who contract CMV are asymptomatic, meaning they experience no signs or symptoms and are often unaware of the infection.
CMV Symptoms in Healthy Individuals
Infection with CMV can occasionally cause mild, flu-like symptoms in healthy adults and children. These may include:
- Fever
- Sore throat
- Fatigue
- Swollen glands
In less frequent cases, CMV can be responsible for more pronounced conditions such as mononucleosis or hepatitis (inflammation of the liver). These conditions are still generally manageable in healthy individuals but warrant medical attention.
CMV Symptoms in People with Weakened Immune Systems
For individuals with compromised immune systems, CMV infection can present more serious health challenges. If you have a weakened immune system due to conditions like HIV/AIDS, organ transplantation, or certain medical treatments, CMV can lead to more severe symptoms affecting various parts of the body, including:
- Eyes: CMV retinitis, which can cause vision problems and even blindness.
- Lungs: CMV pneumonitis, leading to breathing difficulties.
- Liver: Hepatitis and liver dysfunction.
- Esophagus, Stomach, and Intestines: Gastrointestinal issues causing pain, ulcers, and difficulty eating.
CMV and Babies: Congenital CMV
One of the most significant concerns surrounding CMV is its impact on babies. Babies born with CMV, known as congenital CMV infection, can experience a range of health problems. These can include:
- Brain damage and developmental delays
- Liver and spleen problems
- Lung issues
- Growth problems
The most common long-term consequence of congenital CMV infection is hearing loss. This hearing loss can be present at birth or develop later in childhood. Congenital CMV is, in fact, the most common infectious cause of birth defects in the United States, highlighting the importance of awareness and preventative measures.
Keep Reading: CMV in Newborns
Who is at Risk of CMV?
While anyone can contract CMV, certain groups are at a higher risk of experiencing complications from CMV infection. These groups include:
- Pregnant women: CMV can be transmitted from a pregnant woman to her unborn baby, leading to congenital CMV.
- Individuals with weakened immune systems: As discussed, those with compromised immunity are more susceptible to severe CMV symptoms.
- People in close contact with young children: Children, especially those in daycare settings, are a common source of CMV transmission.
CMV and Pregnancy: Congenital CMV Risk
If a woman becomes infected with CMV during pregnancy, she can pass the virus to her developing baby. This is known as congenital CMV. Approximately 1 in 200 babies are born with congenital CMV infection. Of these, about 1 in 5 will have birth defects or other long-term health problems. This makes CMV a leading cause of congenital infections and underscores the importance of preventative measures, especially for pregnant women or women planning to become pregnant.
How CMV Spreads
Understanding how CMV spreads is key to preventing infection. CMV is transmitted through bodily fluids. These fluids include:
- Saliva
- Urine
- Blood
- Tears
- Semen
- Breast milk
Common Modes of CMV Transmission
CMV can spread through various forms of contact with these bodily fluids:
- Direct contact with saliva or urine: This is particularly common with babies and young children, who may shed the virus in their saliva and urine for extended periods after infection.
- Sexual contact: CMV can be transmitted through sexual intercourse.
- Breast milk to nursing infants: While CMV can be present in breast milk, the benefits of breastfeeding generally outweigh the risks for full-term, healthy infants. However, in premature infants, CMV in breast milk can sometimes be more concerning.
- Organ transplantation and blood transfusions: CMV can be transmitted through infected organs or blood, although screening and preventative measures have significantly reduced this risk.
- During pregnancy: As mentioned, CMV can cross the placenta from mother to baby during pregnancy.
Children as a Common Source of CMV
Children are a common source of CMV transmission, especially young children in daycare or preschool settings. The virus can persist in a child’s body fluids for months after initial infection, often without them showing any symptoms. This prolonged shedding and close contact in childcare environments increases the likelihood of transmission to caregivers and other adults.
CMV Prevention Strategies
While there is no vaccine to prevent CMV, you can significantly reduce your risk of infection by practicing good hygiene and taking simple preventative measures, especially when interacting with babies and young children.
Key CMV Prevention Tips
- Wash your hands frequently: Thorough handwashing with soap and water, especially after changing diapers, feeding children, wiping noses, or handling children’s toys, is crucial.
- Avoid sharing food, drinks, and utensils: Do not share food, drinks, cups, forks, spoons, or pacifiers with young children.
- Clean toys and surfaces: Regularly clean toys, countertops, and other surfaces, particularly in childcare settings.
- Practice safe sex: Using condoms can reduce the risk of CMV transmission through sexual contact.
By consistently practicing these hygiene measures, you can lower your chances of contracting and spreading CMV.
CMV Testing and Diagnosis
If you suspect you may have a CMV infection, or if your newborn baby shows potential symptoms, healthcare providers can perform tests to diagnose CMV.
CMV Testing for Adults
For adults experiencing symptoms that could be related to CMV, healthcare providers typically order blood tests. These tests can detect the presence of CMV antibodies, indicating a past or current infection. However, blood tests may not be the most effective way to diagnose CMV in newborns.
CMV Testing for Newborns
For newborns suspected of having congenital CMV, saliva or urine tests are the preferred diagnostic methods. It’s crucial that these tests are performed within 2 to 3 weeks of birth to accurately confirm congenital CMV infection. Testing after this period may not reliably distinguish between congenital infection and infection acquired shortly after birth.
Keep Reading: Laboratory Testing for CMV and Congenital CMV
CMV Treatment and Recovery
For most healthy individuals infected with CMV, medical treatment is usually not necessary. The body’s immune system typically controls the virus without intervention.
CMV Treatment for Specific Groups
Antiviral medications are available to treat CMV infection in specific populations who are at higher risk of complications:
- People with weakened immune systems: Antivirals can help manage and reduce the severity of CMV infection in immunocompromised individuals.
- Babies with symptomatic congenital CMV: Antiviral treatment may be used for newborns who show signs of congenital CMV infection at birth.
Valganciclovir is an antiviral medication that has shown promise in improving hearing and developmental outcomes in babies with symptomatic congenital CMV. However, it is important to note that this medication can have significant side effects and has primarily been studied in babies with clear symptoms of congenital CMV. The effectiveness of valganciclovir for infants with isolated hearing loss due to CMV is still being researched.
Ongoing Care for Children with Congenital CMV
Children with congenital CMV require ongoing monitoring and care. Regular hearing and vision checks are essential to detect and manage any related issues. Additionally, these children may benefit from therapies and support services to help them develop strong language, communication, and motor skills. Early intervention and support are crucial for optimizing the long-term health and development of children with congenital CMV.
CDC’s Role in Addressing CMV
The Centers for Disease Control and Prevention (CDC) is actively working to reduce the impact of congenital CMV infection. The CDC collaborates with national experts to conduct research and enhance public and healthcare provider awareness about CMV.
CDC’s CMV Activities
The CDC’s efforts include:
- Research: Evaluating newborn screening tests for CMV, determining effective screening approaches, studying the long-term impacts of congenital CMV, and characterizing the disease in different populations.
- Education: Updating the CDC’s CMV website with the latest information, developing educational resources for pregnant women, parents, and healthcare providers, and collaborating with partners to disseminate CMV information.
- National CMV Awareness Month: Promoting National CMV Awareness Month in June to increase public understanding of CMV and congenital CMV.
National CMV Awareness Month
Since 2011, June has been designated as “National CMV Awareness Month” in the United States, thanks to a Congressional resolution. During this month, the CDC and partner organizations provide resources and campaigns to educate healthcare providers, pregnant women, and parents about CMV, aiming to reduce the incidence and impact of congenital CMV infection.
Raising awareness is vital because approximately 1 out of every 200 babies is born with congenital CMV infection, and many are unaware of this significant health issue.
Resources for Further Information
For more detailed information and support related to CMV, please refer to these resources:
About Hearing Loss in Children – Information from the CDC on hearing loss in children.
Reducing Risks of Birth Defects | ACOG – American College of Obstetricians and Gynecologists resource on reducing birth defect risks.
National CMV Foundation – A non-profit organization dedicated to CMV awareness, prevention, and support.
Parent to Parent Support Network
The National Congenital CMV Disease Registry offers a Parent to Parent Support Network, assisting nearly 600 families affected by CMV. This network provides a platform for families to share information, offer mutual support, and connect with others facing similar experiences.
Get involved to learn more about the support network and how to connect with other families.
