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CMV blood test

The CMV blood test determines the presence of substances (proteins) called antibodies to a virus called cytomegalovirus (CMV) in the blood.

How the Test is Performed

How to Prepare for the Test

There is no special preparation for the test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

The test is performed to detect current active CMV infection, or past CMV infection in people who are at risk of reactivation of infection (such as organ transplant recipients and people with a suppressed immune system). The test may also be performed to detect CMV infection in newborns.

Normal Results

People who have never been infected with CMV have no detectable antibodies to CMV.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

The presence of antibodies to CMV indicates a current or past infection with CMV. If the number of antibodies (called the antibody titer) rises over a few weeks, it may mean that you have a current or recent infection.

Long-term (chronic) CMV infection (in which the antibody count stays about the same over time) can reactivate in a person with a suppressed immune system.

Risks

Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

Considerations

To detect a blood or organ infection with CMV, the provider can test for the presence of CMV itself in the blood or a specific organ.

Alternative Names

CMV antibody tests

Images

References

Chernecky CC, Berger BJ. Cytomegalovirus antibody – serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:431-432.

Crumpacker CS. Cytomegalovirus (CMV). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 140.

Review Date 9/27/2017

Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.