Lyme disease blood test
How is the Test Performed?
A blood sample is needed.
A laboratory specialist looks for Lyme disease antibodies in the blood sample using the ELISA test. If the ELISA test is positive, it must be confirmed with the Western blot test.
Preparation for the Test
You do not need special steps to prepare for this test.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why is the Test Performed?
The test is done to help confirm the diagnosis of Lyme disease.
Normal Results for Lyme disease blood test
A negative test result is normal. This means none or few antibodies to Lyme disease were seen in your blood sample. If the ELISA test is negative, usually no other testing is needed.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
A positive ELISA result is abnormal. This means antibodies were seen in your blood sample. But, this does not confirm a diagnosis of Lyme disease. A positive ELISA result must be followed up with a Western blot test. Only a positive Western blot test can confirm the diagnosis of Lyme disease.
For many people, the ELISA test remains positive, even after they have been treated for Lyme disease and no longer have symptoms.
A positive ELISA test may also occur with certain diseases, such as rheumatoid arthritis.
Lyme disease blood test Risks
Veins and arteries vary in size, so it may be harder to take a blood sample from one person than another.
Other slight risks from having blood drawn 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)
LaSala PR, Smith MB. Spirochete infections. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 59.
Steere AC. Borrelia burgdorferi (lyme disease, lyme borreliosis). In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 242.
|Review Date: 2/3/2014
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.