Campylobacter serology test is a blood test to look for antibodies to a bacteria called campylobacter.

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

The sample is sent to a lab, whereserology tests are done to look for antibodies to campylobacter. 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.

There is no special preparation.

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.

This test is used to detect the presence of antibodies to campylobacter in the blood. Infection with campylobacter can cause an infectious diarrheal illness.

No antibodies to campylobacter are present.

An abnormal result means that antibodies against campylobacter have been detected. This means you have been exposed to the bacteria.

Tests are often repeated during the course of an illness to detect a rise in antibody levels. This rise helps to confirm an active infection. A low level 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.

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

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