WellSpan Home

Health Library

Cytomegalovirus (Blood)

Does this test have other names?

CMV (serum), cytomegalovirus serologic test, cytomegalovirus antibody, IgG, IgM

What is this test?

This test looks for antibodies to cytomegalovirus (CMV), a virus in the herpes family, in your blood.

CMV is so widespread that most people in the U.S. have been infected by the time they reach age 40, although many don't realize it. You can pick up the virus by handling or exchanging bodily fluids, such as saliva, blood, urine, breast milk, and semen. The virus usually causes only a mild illness, but it can do serious harm to unborn children, people with HIV/AIDS, or others with a weak immune system.

Antibodies are germ-fighting molecules that your immune system makes in response to infection. If you have CMV-specific antibodies in your blood, you may have a CMV infection.

Like other herpes family viruses, cytomegalovirus hides in the body after the first infection and can flare up again. Later infections tend to be milder. In fact, in adults with a healthy immune system, the first infection may not have any symptoms.

Why do I need this test?

You may have this test if you have unexplained symptoms that resemble the flu. If you've been infected with the virus, you may have these signs and symptoms:

  • Prolonged high fever

  • Fatigue

  • Loss of appetite

  • Muscle and joint pain or stiffness

  • Headache

  • Sore throat

  • Swollen lymph nodes

  • Swollen liver and spleen

You may also have this test if you are pregnant, have HIV or are a transplant donor or recipient. If you have a current infection, your healthcare provider can give you certain medicines to reduce the danger of congenital CMV in infants or of active illness in people with a weakened immune system.

Only a lab test can confirm that you have CMV.

What other tests might I have along with this test?

Your healthcare provider may also order other tests for CMV antibodies. These include tests of your cerebrospinal fluid (CSF) and urine. Your healthcare provider may also order tests to look for CMV antigens that CMV antibodies are meant to fight. A CMV antigen test may be called a CMV antigen assay or a CMV Ag test. (Ag stands for antigenemia, meaning antigen-in-blood.)

Your healthcare provider may also order a test called polymerase chain reaction to hunt for the DNA of CMV in your urine, saliva, blood, CSF, or biopsy tissue. He or she may also order a viral culture test from any of these sample types.

Your healthcare provider may also order:

  • Complete blood count, or CBC

  • Mononucleosis or Epstein-Barr virus test

He or she may also test for pneumonia, hepatitis, and gastrointestinal problems.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

Results are given in amounts of two kinds of antibodies: immunoglobulin M (IgM) and immunoglobulin G (IgG).

If your IgM and IgG levels are high, it may mean you have CMV. Your healthcare provider will likely give you the test again in two weeks to confirm the infection. If your IgG levels rise between the first and second test, that may mean you have an active infection. The fact that your IgG level increases is more important than the amount of IgG found. The increase shows that your immune system is busy fighting an infection and that the antibodies are not just left over from an earlier fight.

If your results are higher, it may also mean that you have a connective tissue autoimmune disease, such as rheumatoid arthritis or systemic lupus erythematosus.

If your immune system is weakened, you may have lower results even with an active infection.

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

What might affect my test results?

Other factors aren't likely to affect your results.

How do I get ready for this test?

You don't need to prepare for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.

Cytomegalovirus (Blood) - WellSpan Health

Author: Dudley, David R
Online Medical Reviewer: Sather, Rita, RN
Online Medical Reviewer: Ziegler, Olivia W., MS, PA
Last Review Date: 2015-08-09T00:00:00
Last Modified Date: 2015-08-19T00:00:00
Published Date: 2015-08-19T00:00:00
Last Review Date: 2012-07-09T00:00:00
© 2016 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

I would like to:

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to https://my.wellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.