Testing Resources

Common Tick-Borne Infection Tests

When you see your health care practitioner for a tick bite and get tested for Lyme disease, it may come back as “negative.” Here’s why. The two most common blood tests to detect Lyme: Western Blot and ELISA. Both of these tests DO NOT look for the bacteria itself. Instead, they measure the antibodies that your immune system makes in response to the Lyme bacteria.  

After a tick bite, it can take 4-6 weeks for the body to produce measurable levels of antibodies. So, patients who are tested early in a recent infection may test negative, even if they have the classic bull’s-eye rash, which indicates the positive presence of Lyme disease. This test result is called a false negative. In the early stages of Lyme infection, many patients will have a false negative Lyme test.

In a 2016 review of 50 Lyme studies, 18 were used in the analysis.  These 18 met strict criteria for the most rigorous determination of Lyme infection.  With those 18, it was found the average sensitivity (accuracy) of the two tiered Lyme tests was 53.7%. This means using the CDC required testing, almost half of Lyme patients receive inaccurate and false negative results. Lyme testing is particularly inaccurate in early Lyme. 

We have heard from many patients who tested negative several times before receiving a positive Lyme test. This may depend on which tests are utilized and whether Lyme is impacting their immune function.  

Patients are often told that the only reliable tests are FDA approved. That is not the case – US laboratories are licensed and monitored by CLIA (Clinical Laboratory Improvement Amendments) which ensures they meet quality standards and that the tests are reliable. FDA reviews and approval are only required if the tests are being sold for use by other healthcare organizations or laboratories. A large percentage of available tests today for medical purposes are not FDA approved.  So a useful test must be conducted by either a CLIA-certified lab or an FDA-approved one