These tests may help diagnose Lyme disease, which is caused by a spirochete called Borrelia burgdorferi.
A person may be suspected of having Lyme disease on the basis of a characteristic skin lesion at the site of a tick bite, or on the basis of other symptoms if he or she has been in an environment where ticks are known to be present (recently, or in the distant past if the symptoms are of long duration).
A blood sample is taken from a vein on the arm or hand. First, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube, or "tourniquet," is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them.
A fine needle is gently inserted into a vein, and the tourniquet is removed. Blood flows from the vein through the needle, and is collected in a syringe or vial. After the needle is withdrawn, the puncture site is covered with a bandage for a short time to stop bleeding.
One or more of several antibody tests are then carried out with the patient's blood.
Specific instructions are available from the healthcare professional.
Normal persons will usually have negative reaction to the antibody test. If an antibody test is positive, it may indicate only that a person has had the disease in the past, not necessarily that the disease is active now and needs treatment.