Lyme Disease Test

A Lyme disease test detects Reference antibodies Opens New Window to the Reference Lyme disease Opens New Window bacteria Borrelia burgdorferi in the blood.

Test results are usually available in 1 to 2 weeks.

Normal (negative) values

A normal, or negative, test for Lyme disease can mean one of the following:

• You do not have Lyme disease. A negative PCR test usually means that you do not have a Lyme disease infection.
• You have Lyme disease but it does not show up on the test (Reference false-negative Opens New Window). This is more likely with the antibody tests than with PCR. Reasons for a false-negative result include the following:
  • You have not yet made antibodies to the Lyme disease bacteria. The infection may be present, but it is too early to find antibodies. This is most likely to occur during the first several weeks of infection.
  • Blood levels of antibodies against Lyme disease bacteria are too low for the test to detect.
  • Occasionally, some people who were not treated correctly with antibiotics in the early stage of infection may not have antibodies to the Lyme disease bacteria in later stages of the illness.

Abnormal (positive) values

An abnormal, or positive, test for Lyme disease can mean one of the following:

• If antibodies are found, you may either have Lyme disease now or had the illness in the past. Once you have a Lyme disease infection, antibodies to the bacteria will usually stay in your body for the rest of your life.
• If Lyme disease bacteria DNA is found, you probably have an active Lyme disease infection.
• The result is a Reference false-positive Opens New Window. Sometimes an antibody test for Lyme disease finds antibodies to other bacteria, such as Reference syphilis Opens New Window, or viruses, such as the Reference Epstein-Barr virus Opens New Window or the Reference human immunodeficiency virus (HIV) Opens New Window. The test may also find antibodies that develop as part of an immune response against the body's own tissues (Reference autoimmune disease Opens New Window), such as Reference rheumatoid arthritis Opens New Window or Reference lupus Opens New Window. Your doctor may not be able to tell if the antibodies found in these tests are caused by a current Lyme disease infection.

The PCR test may be done to confirm an infection if you have a positive antibody test result.

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