Cytomegalovirus (CMV) IgG Antibody Index (Serum)

Why This Test Is Done

Doctors may order this test if you have symptoms of CMV infection, such as fever, fatigue, or organ damage, or if you’re at higher risk for CMV complications, like people with weakened immune systems or those undergoing organ transplants. It can also help monitor immune function in certain conditions.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into a vein (usually in your arm) to draw blood. The process takes a few minutes, and you may feel a brief pinch. If you’re nervous, let your healthcare provider know.

What the Test Results Mean

A positive result means you likely have been exposed to CMV at some point and your body has produced antibodies to fight it. A negative result suggests you may not have been exposed recently or have no detectable antibodies. Results alone don’t confirm active infection; they indicate past exposure.

Possible Results and Next Steps

If your result is positive, your doctor may recommend additional tests to check for active CMV infection, such as a CMV IgM antibody test. If you’re at risk for complications, they might also monitor you closely or adjust treatments accordingly.