Definition
Campylobacter serology test determines if there are antibodies to the bacterium campylobacter in the blood.
How the test is performed
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic. An elastic band is placed around the upper arm to apply pressure and cause the vein to swell 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 infants or young children, 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. A bandage may be applied to the puncture site if there is any bleeding.
Serology refers to the study of serum (the fluid portion of blood) for its antibody content. An antibody defends the body against bacteria, viruses, fungus, or other foreign bodies (antigens). Certain microbial cells 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, few antibodies may be detected. For this reason, serology tests are often repeated 10 days - 2 weeks 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 specific microorganism.
How to prepare for the test
There is no special preparation.
How the test will feel
When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
This test is used to detect the presence of antibodies to campylobacter in the blood. Infection with campylobacter can cause an infectious diarrheal illness.
Normal Values
No antibodies to campylobacter are present.
What abnormal results mean
Abnormal results indicate antibodies against campylobacter. This means you have been exposed to the bacteria. Tests will show an increase in the antibody titer from the beginning of the illness to several weeks later, to distinguish current illness from previous exposure. A titer is a measure of the concentration of a substance in a sample.
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
Serology tests are often repeated during the course of an illness to detect a rise in antibody titers. This rise helps to confirm an active infection. A low titer may indicate a previous infection rather than a current disease.
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.
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Reviewed By: Kenneth Wener, M.D., Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA. Review provided by VeriMed Healthcare Network.
