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 three types of antibody tests to detect Lyme disease.
Antibody testing should be done in a two-step process, using either the ELISA or IFA followed by the Western blot test. ELISA is considered a more reliable and accurate test than IFA, but IFA may be used if ELISA is not available. The Western blot test (which is a more specific test) should be done in all people who have tested positive or borderline positive (equivocal) in an ELISA or IFA test.
A Lyme disease test is done to diagnose Lyme disease in people who have symptoms of Lyme disease. Symptoms may include:
Symptoms of chronic Lyme disease infection include joint pain, stiffness, and problems with the heart, brain, or nerves.
Testing is most accurate when you have risk factors for Lyme disease or symptoms of the disease.
You do not need to do anything before you have this test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
The health professional taking a sample of your blood will:
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having blood sample taken from a vein.
A Lyme disease test detects antibodies to the Lyme disease bacteria Borrelia burgdorferi in the blood. The results of a Lyme disease test to detect antibodies (ELISA, IFA, Western blot) may be reported in titers. A titer is a measure of how much the sample can be diluted before the antibodies to the Lyme disease bacteria can no longer be detected.
A titer of 1 to 8 (1:8) means that antibodies can be detected when 1 part of the blood sample is diluted by up to 8 parts of a salt solution (saline). A larger second number means there are more antibodies in the blood. Therefore, a titer of 1 to 128 indicates more Lyme disease antibodies in the blood than a titer of 1 to 32.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Test results are usually available in 1 to 2 weeks.
No antibodies to Lyme disease bacteria are found.
For the IFA test, the titer is less than 1:256.
The polymerase chain reaction (PCR) test does not find any Lyme disease bacteria DNA.
Antibodies to Lyme disease bacteria are found.
For the IFA test, the titer is equal to or greater than 1:256.
The polymerase chain reaction (PCR) test detects Lyme disease bacteria DNA.
A normal, or negative, test for Lyme disease can mean one of the following:
An abnormal, or positive, test for Lyme disease can mean one of the following:
The PCR test may be done to confirm an infection if you have a positive antibody test result.
Reasons you may not be able to have the test or why the results may not be helpful include:
Other Works Consulted
- American Academy of Pediatrics (2009). Lyme disease. In LK Pickering, ed., Red Book: 2009 Report of the Committee on Infectious Diseases, 28th ed., pp. 430–435. Elk Grove, IL: American Academy of Pediatrics.
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
- National Institutes of Health, U.S. Department of Health and Human Services (2008). Lyme Disease: The Facts, the Challenge (NIH Publication No. 08-7041). Available online: http://www.niaid.nih.gov/topics/lymeDisease/Documents/lymedisease.pdf.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Specialist Medical Reviewer||Christine Hahn, MD - Epidemiology|
|Last Revised||August 31, 2010|
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