Cytomegalovirus Antibody, Serum (Qualitative or Quantitative Immunoassay)

Why This Test Might Be Ordered

Your healthcare provider may order this test if you have symptoms like fatigue, fever, or organ damage that could suggest a past CMV infection. It’s also used before organ transplants to check for immunity in donors or recipients, or in pregnancy to assess risk for congenital CMV in the baby.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test looks for antibodies in your serum (liquid part of blood) using an immunoassay method, which detects specific proteins your body makes in response to CMV.

What the Results Mean

A positive result means your body has made antibodies to CMV, suggesting you’ve likely had the infection at some point. A negative result indicates no detectable antibodies, meaning you either haven’t been infected or your immune system cleared it quickly. Results aren’t always definitive for recent infection alone.

Common Uses and Limitations

This test is useful for confirming past infection or immunity but isn’t designed to diagnose active CMV disease or recent exposure. It’s not a replacement for other tests like viral load measurements if symptoms persist or further evaluation is needed.