Lyme Disease Test
A Lyme disease test detects antibodies to the Lyme disease bacteria Borrelia burgdorferi in the blood. Lyme disease bacteria are spread by certain kinds of ticks.
Lyme disease can be hard to diagnose because its symptoms are similar to those of many other illnesses. If you and your doctor think you have Lyme disease, your doctor will do a careful medical history and physical exam. Antibody tests can sometimes be used to help identify Lyme disease. Other tests may be done in certain situations.
Antibody tests are the most commonly used tests to help identify Lyme disease. Antibody testing may also be done on fluid from the spine or from a joint.
It may take up to 2 months after becoming infected before antibodies can be detected in a blood test. Once formed, antibodies usually stay in your system for many years, even after successful treatment of the disease. Finding antibodies to the Lyme disease bacteria does not tell whether you were infected recently or sometime in the past.
There are two types of antibody tests to detect Lyme disease.
Enzyme-linked immunosorbent assay (ELISA). This common and rapid test to identify Lyme disease antibodies is the most sensitive screening test for Lyme disease.
Western blot test. This test also identifies Lyme disease antibodies and can confirm the results of an ELISA test. It is most often done to detect a chronic Lyme disease infection.
Antibody testing should be done in a two-step process, using the ELISA followed by the Western blot test. The Western blot test (which is a more specific test than the ELISA) should be done in all people who have tested positive or borderline positive (equivocal) in an ELISA test.
Polymerase chain reaction (PCR) test. Polymerase chain reaction (PCR) testing detects the genetic material (DNA) of the Lyme disease bacteria. PCR testing may be used to identify a current (active) infection if you have symptoms of Lyme disease that have not gotten better with antibiotic treatment. PCR testing is not done as often as antibody testing because it requires technical skill and expensive equipment. Also, standards have not yet been developed for PCR testing and there is a risk of false-positive test results.