What is Cytomegalovirus (CMV)?

Cytomegalovirus (CMV) is a common virus that can infect people of all ages. It is part of the herpesvirus family, which also includes viruses like herpes simplex and varicella-zoster (chickenpox). CMV is typically harmless for most healthy individuals, often causing no symptoms or mild ones. However, it can be serious for people with weakened immune systems, and it can also cause complications for infants born to mothers who are infected.

CMV is spread through bodily fluids, including saliva, urine, blood, breast milk, semen, and organ transplants. It is most commonly transmitted through direct contact with these fluids or from mother to baby during pregnancy (congenital CMV).

What Causes Cytomegalovirus Infection?

CMV is caused by the cytomegalovirus, which is part of the herpesvirus family. Most people are infected with CMV at some point in their lives, often without realizing it. The virus remains dormant in the body once infected, and it can become reactivated if the person’s immune system is weakened.

Factors that increase the risk of CMV infection include:

1. Close contact with infected individuals: The virus is spread through saliva, urine, and other bodily fluids. People who care for infants or children in daycare settings are at a higher risk.
2. Weakened immune system: Individuals with weakened immune systems, such as those with HIV/AIDS, cancer patients undergoing chemotherapy, or organ transplant recipients, are at higher risk for severe CMV infections.
3. Pregnancy: Pregnant women who contract CMV can pass the virus to their baby during pregnancy, birth, or breastfeeding, leading to congenital CMV.
4. Unprotected sexual contact: CMV can be transmitted through sexual contact, including vaginal, anal, and oral sex.
5. Organ transplants and blood transfusions: Receiving an organ transplant or blood transfusion from a CMV-infected donor can also lead to infection.

What Are the Symptoms of Cytomegalovirus Infection?

In healthy individuals, CMV infection usually doesn’t cause symptoms or causes mild flu-like symptoms, including:

• Fever
• Fatigue
• Sore throat
• Swollen lymph nodes
• Muscle aches
• Mild liver inflammation (hepatitis)

In people with weakened immune systems, the symptoms can be more severe and may include:

• Vision problems
• Pneumonia
• Gastrointestinal issues (diarrhea, nausea)
• Liver problems
• Inflammation of the brain (encephalitis)

For infants born with congenital CMV, symptoms may include:

• Jaundice (yellowing of the skin and eyes)
• Low birth weight
• Microcephaly (small head)
• Hearing loss
• Seizures
• Skin rashes

How is Cytomegalovirus Infection Diagnosed?

Diagnosis of CMV typically involves a combination of clinical evaluation and laboratory tests. Your doctor may ask about your symptoms, medical history, and any recent exposure to individuals with CMV.

Common diagnostic tests include:

1. Blood tests: Blood tests can detect the presence of CMV antibodies or viral DNA. A positive test for CMV antibodies means that a person has been exposed to the virus, but it doesn’t necessarily indicate an active infection.
2. Polymerase chain reaction (PCR): This test detects the presence of CMV DNA in blood, urine, or other bodily fluids and can confirm an active infection.
3. Viral culture: In some cases, doctors may culture a sample of saliva, urine, or blood to check for the CMV virus.
4. Ultrasound or imaging tests: For congenital CMV, imaging tests like ultrasounds may be used to assess the baby’s health and detect complications such as microcephaly.

How is Cytomegalovirus Infection Treated?

Most healthy individuals with CMV infection do not require treatment since the infection typically resolves on its own or causes only mild symptoms. However, for people with weakened immune systems or infants with congenital CMV, antiviral treatment may be necessary.

Common treatment options include:

1. Antiviral medications: Drugs like ganciclovir, valganciclovir, and foscarnet can help to treat CMV infections in individuals with compromised immune systems. These medications work by stopping the virus from replicating.
2. Supportive care: For mild cases, supportive care such as rest, hydration, and pain relievers may be sufficient to alleviate symptoms.
3. Treatment for complications: If CMV leads to more severe complications, such as pneumonia, liver damage, or vision problems, additional treatments may be necessary to manage those issues.

For pregnant women, antiviral treatment is sometimes used to reduce the risk of transmitting CMV to the baby, especially if the mother has primary infection during pregnancy. However, there are no vaccines currently available for CMV.

How Can Cytomegalovirus Infection Be Prevented?

While it’s not always possible to completely prevent CMV infection, there are steps you can take to reduce the risk, especially for pregnant women or those with weakened immune systems.

1. Good hygiene practices: Wash your hands frequently, especially after handling items that may have come in contact with saliva or urine (e.g., diapers, toys, bottles). This is particularly important for caregivers of young children, as CMV is common in young children.
2. Avoid sharing utensils or food: Do not share food, drinks, or utensils with young children who may be shedding the virus.
3. Use condoms: CMV can be transmitted through sexual contact, so using condoms during sex can reduce the risk of transmission.
4. Avoid contact with saliva or urine: Pregnant women should be especially cautious around young children, as CMV can be spread through contact with saliva and urine. Limit kissing children on the lips or sharing food or utensils.
5. Screening and antiviral treatment: Pregnant women at high risk for CMV (e.g., those who work in daycare or healthcare settings) may be offered screening for CMV infection and antiviral treatment to reduce the risk of passing the virus to the baby.

What Are the Complications of Cytomegalovirus Infection?

While most people with CMV infection experience mild or no symptoms, the virus can cause serious complications in certain groups:

1. Congenital CMV: Babies born with CMV infection may experience long-term complications, including hearing loss, vision problems, developmental delays, and in severe cases, brain damage.
2. Immunocompromised individuals: People with weakened immune systems, such as those with HIV/AIDS, organ transplant recipients, or cancer patients, are at risk of severe CMV infections that can cause pneumonia, gastrointestinal issues, and other organ damage.
3. Retinitis: CMV can cause inflammation of the retina in people with weakened immune systems, leading to vision loss if left untreated.
4. Neurological damage: In rare cases, CMV infection can lead to encephalitis, or inflammation of the brain, which can cause long-term neurological damage.