Types of Lyme Disease Tests Explained
There are several types of Lyme disease tests used in clinical practice, including the ELISA, Western blot, PCR, and culture tests. While these laboratory tests can support the diagnosis, Lyme disease is often best diagnosed clinically based on symptoms, exposure history, and physical findings.
Many physicians rely heavily on laboratory testing. However, studies have shown that Lyme disease tests can have significant limitations, including false negatives and variable sensitivity depending on the stage of infection.
- Several types of Lyme disease tests are used, including ELISA, Western blot, PCR, and culture.
- Many Lyme disease tests detect antibodies rather than the bacteria itself.
- Testing can be falsely negative, especially early in infection.
- Clinical judgment remains essential when diagnosing Lyme disease.
In this article:
- Clinical diagnosis remains essential
- Why Lyme disease tests can be inaccurate
- Most common types of Lyme disease tests
- Testing for Lyme disease co-infections
Clinical diagnosis remains essential
Often the diagnosis of Lyme disease depends on a physician’s willingness to listen carefully to the patient and obtain a detailed history, including possible exposure to ticks.
Lyme disease should not be ruled out simply because laboratory tests are negative. Numerous studies have documented that commonly used tests may fail to detect infection, particularly early in the illness. For a broader discussion of this issue, see Lyme disease diagnosis and testing.
“Effective communication and engaging your patient to elicit a complete medical history including any possible exposure to ticks is critical in making a diagnosis.”
— Dr. Daniel Cameron
Why Lyme disease tests can be inaccurate
The accuracy of Lyme disease tests varies for several reasons.
- The stage of infection
- The patient’s immune response
- Prior antibiotic treatment
- Differences among Borrelia strains
Antibodies to Borrelia burgdorferi typically do not appear in the blood until approximately four to six weeks after a tick bite. If a patient receives antibiotics early, antibody levels may remain too low to detect.
Additionally, the Lyme bacteria are not always present in the bloodstream, which can make direct detection difficult.
Most common types of Lyme disease tests
The most commonly used laboratory tests for Lyme disease include:
- ELISA (enzyme-linked immunosorbent assay)
- Western blot
- Two-tier antibody testing
- C6 peptide ELISA
- PCR testing
- Culture testing
Each of these tests has advantages and limitations.
ELISA Lyme disease test
The ELISA is typically used as the first screening test for Lyme disease. It measures antibodies produced by the immune system against Borrelia burgdorferi.
However, studies have shown that the ELISA test may have poor sensitivity, particularly early in the infection.
Research has reported sensitivity ranging from 33% to 49% among patients presenting with an erythema migrans rash. This means that more than half of infected patients could test negative.
Western blot Lyme test
The Western blot test identifies specific antibody bands that react with proteins from Borrelia burgdorferi.
According to CDC surveillance criteria:
- IgM Western blot requires 2 of 3 bands (23, 39, and 41 kDa)
- IgG Western blot requires 5 of 10 bands
While more detailed than the ELISA test, the Western blot can still miss cases of Lyme disease and may be difficult to interpret.
For additional discussion of antibody testing limitations, see Lyme disease test accuracy.
Two-tier Lyme testing
The CDC recommends a two-tier testing system in which an ELISA test is performed first. If the ELISA is positive or indeterminate, it is followed by a Western blot.
However, this approach can miss cases because both tests must be positive. Studies have reported sensitivities as low as 35% to 38% in patients with confirmed Lyme disease.
PCR Lyme test
PCR (polymerase chain reaction) testing attempts to detect the DNA of Borrelia burgdorferi rather than antibodies.
Unfortunately, PCR testing has relatively low sensitivity in Lyme disease, often ranging from 5% to 25% in routine clinical practice.
Culture testing
Culturing Borrelia burgdorferi is difficult because the organism grows slowly and may not be present in the blood once infection has spread beyond the initial rash.
New culture methods are under investigation and may improve detection rates in the future.
Testing for Lyme disease co-infections
Testing for tick-borne co-infections such as Babesia, Bartonella, Ehrlichia, and Anaplasmosis can also be challenging.
Laboratory findings may include low white blood cell counts, mild liver enzyme elevations, and low platelets, but these abnormalities may be brief and easily missed.
Because testing remains imperfect, physicians often rely on clinical judgment when evaluating possible co-infections.
Clinical takeaway
Laboratory tests can support the diagnosis of Lyme disease, but they should not replace careful clinical evaluation. Physicians must consider symptoms, exposure history, and physical findings when determining whether Lyme disease may be present.
Frequently Asked Questions About Lyme Disease Tests
Can Lyme disease tests be negative even if someone is infected?
Yes. Antibodies to Borrelia burgdorferi may take several weeks to develop after a tick bite. Testing too early may result in a false-negative result.
What are the most common Lyme disease tests?
The most common types of Lyme disease tests include the ELISA screening test followed by the Western blot confirmation test.
Can Lyme disease be diagnosed without a positive test?
Yes. Lyme disease is often diagnosed clinically based on symptoms, exposure risk, and physical findings.
References
Branda JA, Steere AC. Laboratory diagnosis of Lyme disease. Clinical Microbiology Reviews. 2021.
