Epstein-Barr virus test

Alternative names
EBV antibody test; Monospot; Heterophile agglutination test

Definition
This is a blood test used to detect antibodies to the Epstein-Barr virus (EBV) antigens.

How the test is performed

Blood is drawn from a vein on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

An antibody defends the body against bacteria, viruses, fungus, or other foreign bodies (antigens). Microorganism can stimulate the body to produce these antibodies during active infection. Antibody production increases during the course of infection.

In the initial stage of an illness, little antibody may be detected. For this reason, serology tests (tests performed on serum, the fluid portion of blood that contains antibodies) are often repeated 10 days to 2 weeks or more after the initial sample.

In the laboratory, the antibodies react with antigens in specific ways that can be used to confirm the identity of a microorganism. There are several serology techniques that can be used depending on the suspected antibodies. Serology techniques include agglutination, precipitation, complement-fixation, fluorescent antibodies, and others.

How to prepare for the test
There is no special preparation for the test.

For infants and children:
The preparation you can provide for this test depends on your child’s age and experience. For specific information regarding how you can prepare your child, see the following topics:

     
  • Infant test or procedure preparation (birth to 1 year)  
  • Toddler test or procedure preparation (1 to 3 years)  
  • Preschooler test or procedure preparation (3 to 6 years)  
  • Schoolage test or procedure preparation (6 to 12 years)  
  • Adolescent test or procedure preparation (12 to 18 years)

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 sensation. Afterward, there may be some throbbing.

Why the test is performed
The test is performed to detect an acute (currently active) infection with Epstein-Barr virus (EBV).

Normal Values
No antibodies to EBV will be detected from people who have never been infected with EBV.

What abnormal results mean
The Monospot test (one of the EBV tests) will be positive only during the acute phase of EBV infection. Other more sophisticated and rarely used antibody tests can detect and discern between acute and past infection with the virus.

What the risks are

     
  • Excessive bleeding  
  • Fainting or feeling light-headed  
  • Hematoma (blood accumulating under the skin)  
  • Infection (a slight risk any time the skin is broken)  
  • Multiple punctures to locate veins

Special considerations
Veins and arteries vary in size from one patient 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.

Johns Hopkins patient information

Last revised: December 4, 2012
by Janet G. Derge, M.D.

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