I have updated this article first published in May 2014 to include information about NEW tests from IGenex including its Immunoblot. It also includes updates on western blot and elispot tests. Finally at the end of the article I advise caution regarding a lab system called DNA Connexions.
There are a variety of tests that can help diagnose Lyme disease by finding evidence of Lyme infection. These include ELISA, IFA, PCR, immunoblot done as a western blot, the new immunoblot with synthetic proteins, and blood culture. Although these tests are helpful aids they are far from perfect. In this article I review each of these tests and give them a grade. With these grades in mind, I describe the way I use these tests to help decide if someone has Lyme disease.
At the end of the article I tell you what I think the best Lyme test is and why.
(Note: I do not include the CD-57 test in this review because it only shows immune suppression which may or may not be caused by a Lyme infection. For my review of this test see CD-57 Test? Rarely.)
As you read about the tests, note that a test does not diagnose a disease. As a physician, I do not treat a test; I treat a person. Tests can be wrong. To make a diagnosis I consider
- the risks of getting the infection like having a known tick bite, or a history of hiking where there are a lot of ticks that carry Lyme like in Minnesota, or a number of other risk factors,
- the symptoms,
- physical exam findings, and
- whether there is supportive testing.
Note that I said supportive testing. So the result of testing is only one part I consider in making a diagnosis. See How to Diagnose Chronic Lyme Disease for more information about this complex issue.