Tick-borne diseases have steadily been on the rise, according to the Centers for Disease Control and Prevention (CDC)—and Lyme disease, the most common infection transmitted by ticks (black-legged ones in particular), is among them.1 While nearly 35,000 cases of Lyme disease were reported in 2019, the most recent year with available data, the CDC estimates that number to be much, much higher: up to 476,000.
Lyme disease can lead to a wide array of symptoms—plaguing people with everything from that distinct, bull’s-eye-shaped rash to muscle pain to unbearable fatigue. In rare cases the disease can lead to severe neurological complications, according to the National Institutes of Neurological Disorders and Stroke, so getting a proper diagnosis (and treatment as soon as you can) is crucial.
At-home test kits might feel like a simple solution when you’re looking for answers—especially now that we’re seeing more home tests on the market for illnesses like COVID-19. At-home Lyme disease test kits typically claim to detect antibodies linked to the bacteria that cause Lyme—all you need to do is pay for the kit, read the instructions, send in a blood sample (yes, that you collect yourself), and wait for your results. Simple enough, right?
The problem is that like with any home test that has a margin for user error, your results may not be accurate. This could delay the diagnosis and treatment you may need, regardless of what might be causing your symptoms. That’s partly because there’s a bigger issue with Lyme disease testing in general: It’s not very reliable, even when it’s performed by experts.
First, it’s important to understand how a doctor should test for Lyme disease.
Standard Lyme disease lab testing uses a two-tier system to analyze your blood for antibodies, which is recommended by the CDC. First, you take an enzyme-linked immunosorbent assay (ELISA) test—also known as enzyme immunoassays (EIA)—which aims to detect Immunoglobulin G (IgG) and Immunoglobulin M (IgM) in your blood, or antibodies that your immune system produces in response to the bacteria that cause Lyme, the Borrelia species.2
If you test positive for IgG and IgM antibodies, then the CDC also recommends taking a Western blot test. This test looks for bands, which are barcode-like lines of proteins in the blood that signify IgG and IgM antibodies.3 Alternatively, you may take another ELISA test to confirm the results of the first test.
Some at-home Lyme disease test manufacturers claim to use a similar process to laboratory tests. Others may test urine samples or tissue from your cheeks, which are not recommended testing methods for the identification of Lyme disease antibodies, according to the National Institute of Allergy and Infectious Diseases.
The Food and Drug Administration (FDA) does not approve medical laboratories, but it has cleared the CDC-recommended testing methods above. Some at-home testing companies may conduct their tests in labs that have completed the Clinical Laboratory Improvement Amendments (CLIA) program. The FDA, Center for Medicaid Services (CMS), and CDC oversee the program to ensure labs are following the exact protocols they claim to be, according to the FDA. However, it’s impossible to know what lab each at-home testing company uses because they typically don’t disclose that information.
Lab testing for Lyme disease is notoriously tricky, even for trained doctors.
“Gold-standard” Lyme disease tests are still murky—meaning a kit you buy online may be even less reliable.