Lyme Basics

Lyme Disease Tests

Testing for Lyme disease is complex and often controversial. The most commonly used tests—ELISA and Western Blot—were originally adapted for public health tracking in the 1980s and 1990s, not for diagnosing individual patients. Despite their limitations, they remain part of the CDC’s recommended Standard Two-Tier Testing (STTT) protocol.

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Lyme Disease Tests

Sensitivity vs. Specificity in Lyme Testing

Lyme disease tests are often inaccurate. Two key measures help explain this:

  • Sensitivity refers to a test’s ability to correctly identify people who have the disease. When sensitivity is low—as it often is with Lyme tests—true infections may go undetected, resulting in false negatives. This means patients who are genuinely sick may receive a negative result and miss out on timely diagnosis and treatment.
  • Specificity refers to a test’s ability to correctly rule out those who don’t have the disease. Low specificity can lead to false positives, where people are incorrectly diagnosed with the illness.

The ELISA test, typically used first, has particularly low sensitivity in early Lyme disease, when antibody levels are still building. Even the Western Blot, used to confirm ELISA results, misses many cases. One study showed it detected fewer than 54 out of every 100 confirmed infections.

Understanding Two-Tier Testing

The CDC recommends a two-step process:

  • ELISA: Screens for Lyme antibodies. If the ELISA is negative, no further testing is typically done—even if symptoms persist.
  • Western Blot: Confirms ELISA results by detecting specific Lyme-related protein “bands.”

Western Blot Criteria

  • IgM (early infection, first 30 days): Positive if 2 of 3 bands are present — 23, 39, and 41 kDa.
  • IgG (after 30 days): Positive if 5 of 10 bands are present — 18, 23, 28, 30, 39, 41, 45, 58, 66, and 93 kDa.

Many symptomatic patients fall short of these thresholds, leaving them without a diagnosis or treatment.

Modified Two-Tier Testing (MTTT)

In 2019, the FDA cleared MTTT, a faster alternative that uses two ELISA-type tests instead of a Western Blot. It offers similar accuracy and easier interpretation.

As of 2024, the CDC recognizes both STTT and MTTT as valid. Labs like Labcorp have fully adopted MTTT, though STTT remains widely used. However, both methods can still miss true cases.

IGeneX offers FDA-cleared ImmunoBlot kits:

  • IgG kit approved in 2024
  • IgM kit approved in 2025

These tests detect more strains of Lyme bacteria than standard tests, improving sensitivity without sacrificing specificity. They’re the only kits that detect antibodies to OspA (31) and OspB (34).  The CDC removed 31 and 34 from its Western blot guidelines in the early 2000s to avoid confusion with the Lyme vaccine, which was based on OspA (31). That vaccine was discontinued in 2002, but the exclusion remains — even though most people today were never vaccinated. As a result, some truly infected patients may test negative under CDC criteria simply because these bands aren’t counted.

Direct Detection Tests

Some tests aim to find the Lyme bacteria itself—not just your immune response:

  • PCR: Detects Lyme DNA. Highly specific but often misses infection due to low bacterial presence.
  • Antigen Detection: Searches for Lyme proteins in fluids like blood or joint fluid. May catch infections missed by antibody tests.
  • Culture Testing: Attempts to grow Lyme bacteria. Considered definitive but rarely successful or used clinically.

Testing for Co-Infections

Ticks can carry multiple pathogens. Common co-infections include:

  • Tick-Borne Relapsing Fever Borrelia
  • Babesia microti/Babesia duncani/Babesia odocoilei
  • Anaplasma
  • Ehrlichia
  • Bartonella
  • Rickettsia

Because symptoms overlap, doctors may order additional blood tests. Early detection helps guide effective treatment.

The following labs offer Lyme tests that have been cleared by the FDA:

  1. IGeneX
  2. Stony Brook 

Testing for co-infections

Labs like IGeneX, Galaxy Diagnostics, and Vibrant Wellness offer comprehensive panels that screen for a range of tick-borne co-infections, including:

Babesia, Bartonella, Ehrlichia, Anaplasma, Rickettsia, Borrelia miyamotoi, and more.

These are laboratory-developed tests (LDTs)—created and used within a single certified lab. They’re regulated under CLIA, not the FDA, which means they haven’t gone through federal review. Even so, LDTs can help detect infections that standard tests might miss.

Could your symptoms be due to a tick-borne disease infection?

Take our quiz and see if testing may be right for you.

Do you have Lyme disease?

Answer a few questions in our quiz to find out if you might have Lyme disease or a tick-borne infection.

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