Cytomegalovirus (CMV) Tests
CMV tests detect a common virus in the herpes family, helping identify infections in individuals with weakened immune systems, pregnant women, and newborns.
What are cytomegalovirus (CMV) tests?
Cytomegalovirus (CMV) is a common virus that stays in the body for life, usually remaining dormant. It can reactivate during periods of stress or immune system compromise. While healthy people often have no symptoms, CMV can be dangerous for those with weakened immune systems, pregnant women, and infants.
What are they used for?
Tests help diagnose current, reactivated, or past infections in high-risk groups, including:
- People with weakened immune systems (e.g., HIV, cancer).
- Organ transplant recipients.
- Pregnant women experiencing symptoms.
- Newborns showing signs of infection.
Why do I need a CMV test?
Adults may need testing if they have symptoms like swollen lymph nodes, sore throat, fever, fatigue, or muscle aches. Infants may be tested if they show symptoms such as jaundice, low birth weight, small head size, hearing or vision problems, seizures, or rash.
What happens during a CMV test?
Testing methods vary based on the patient:
- Blood tests: The most common method for adults.
- Cerebrospinal fluid (CSF) analysis: A spinal tap to collect fluid from the spine.
- Sputum test: Collecting mucus from the lungs via coughing or bronchoscopy.
- Biopsy: Removing a small tissue sample using a needle.
- Amniocentesis: Used during pregnancy to check if a fetus is infected.
- Infant tests: Saliva swabs or urine collection bags are used for newborns.
Preparation and Risks
Preparation varies by test type: biopsies and amniocentesis may require fasting or specific bladder instructions. Blood, saliva, and urine tests require no special preparation. Risks are generally low; however, procedures like spinal taps or biopsies may involve minor pain, bruising, or temporary discomfort. Amniocentesis carries a very low risk of complications like cramping or fluid leakage.
What do the results mean?
Results indicate if you have ever been exposed to CMV but cannot distinguish between a past, current, or reactivated infection on their own. Providers use these results alongside clinical symptoms to create a treatment plan. If a baby is diagnosed with congenital CMV, early treatment can help prevent long-term complications.
Prevention
CMV is often part of a TORCH panel for newborns. You can reduce your risk of infection by washing hands after diaper changes, avoiding sharing food or utensils with children, and using barrier protection during sexual activity.