Lyme Disease Testing

Lyme disease is caused by the bacterium Borrelia burgdorferi and, to a lesser extent, Borrelia mayonii. These Borrelia species are transmitted to humans through the bite of an infected blacklegged (deer) tick, Ixodes scapularis, or western blacklegged tick, Ixodes pacificus.

Lyme disease is diagnosed through clinical assessment or clinical assessment supported by laboratory testing. The presence of an erythema migrans (EM) rash is diagnostic of Lyme disease without laboratory investigation, however not 100% prevelant.^1,2 Patients who do not develop a rash but have symptoms suggesting Lyme disease and have been to areas with a high risk of tick exposure, may undergo laboratory testing to help identify the cause of symptoms.^1,2 Serologic testing is the principal means of laboratory diagnosis of Lyme disease.

Yes. Amplification of Borrelia genomic DNA from blood, CSF, fluids, or tissues can support the diagnosis of Lyme disease and should be performed with serologies. In general, blood is not the preferred source for detection of Borrelia DNA by PCR since the genetic material of the spirochete does not stay in the blood very long.³

Quest offers testing in accordance with the Centers for Disease Control and Prevention (CDC) guidelines for early/acute Lyme disease testing.⁴ When laboratory diagnosis is indicated, current recommendations include using a 2-tier testing approach that begins with a sensitive enzyme immunoassay (EIA), followed by a confirmatory immunoassay for specimens yielding positive or equivocal results.⁴

In the standard 2-tier test (STTT) algorithm, a Western blot or immunoblot assay is used for confirmation. However, on July 29, 2019, the US Food and Drug Administration (FDA) cleared several Lyme disease serologic assays with new indications for use, which allowed an EIA (rather than immunoblot assay) to be used as the confirmatory test in a modified 2-tier testing (MTTT) algorithm.⁴ The MTTT algorithm is now considered an acceptable approach for the serologic diagnosis of Lyme disease and may be able to help identify early Lyme disease within the first 30 days of infection.⁴

Quest offers test options for both the STTT and the MTTT algorithms: 

• STTT: Lyme Disease Ab with Reflex to Blot (IgG, IgM) (test code 6646)
• MTTT: Lyme Disease Antibody with Reflex to Immunoassay (IgG, IgM) (test code 39733)

Click here for a list of additional tests available from Quest for tick-borne infectious diseases.  

Compared to the STTT, the MTTT appears to provide similar or improved sensitivity and specificity. In a 356-sample retrospective study of a heterogenous cohort, specimens were collected from healthy and disease-control (without Lyme disease) participants and from patients characterized as having stage I (early acute), stage II (early disseminated), or stage III (late disseminated) Lyme disease; the specimens were tested with both the STTT and MTTT approaches.⁵ The MTTT methodology showed higher sensitivity relative to STTT for Lyme stages I and II (78.3% vs 63.3% for stage I; 66.1% vs 60.7% for stage II), with comparable sensitivity for stage III (100% vs 100%) Lyme disease; specificity did not differ between the 2 methods (97.8% for MTTT vs 100% for STTT).⁵  

Lyme disease cannot be detected immediately after infection using serologic testing. Lyme disease develops in stages: the early stage, which is divided into early localized infection and early disseminated infection, and then a late disseminated infection.¹ Spirochetemia occurs early, with widespread dissemination through tissue and body fluids. However, antibodies usually take at least 2 weeks to develop, so patients may be seronegative within 2 weeks of a suspected tick bite.^1,2,4 The sensitivity of serologic testing increases markedly with the progression of Borrelia burgdorferi infection from early to late Lyme disease.

For patients who have high risk of exposure to Lyme or other tickborne infections and no EM rash before the window of seropositivity, identification of Borrelia species DNA in the blood by polymerase chain reaction (PCR) may be useful within the first 2 weeks of infection.^1,3

Serologic tests may yield false-negative results during early stages of infection, before antibodies have reached detectable levels. In addition, serologic assays may give false-positive results in individuals with other conditions, including ^4,6,7

• Pathogenic spirochetal diseases, such as syphilis, yaws, pinta leptospirosis, relapsing fever, and periodontal disease 
• Other bacterial and viral infections, such as Rocky Mountain spotted fever, Epstein-Barr virus, and cytomegalovirus 
• Connective tissue autoimmune diseases associated with positivity for anti-nuclear antibody, including rheumatoid arthritis and systemic lupus erythematosus

No test can prove Lyme disease is cured. Antibodies frequently persist in the blood for months or even years after the infection is resolved, despite absence of detectable/viable B burgdorferi.⁸ Therefore, antibody tests cannot be used to determine if a patient is cured. Antibiotics used to treat Lyme disease do not cause serology blood tests to become negative.^4,6,7

No. If a person has persistent antibodies from the first Lyme disease infection, the current serology tests available at Quest cannot determine if positivity is due to reinfection or persistence of antibodies from prior infection.^{9, 10}

Ixodes scapularis (deer) ticks can also carry other human pathogens that have a high degree of symptom overlap, including Borrelia miyamotoi, Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Babesia microti.^2,11-13  Several studies on co-infected ticks indicate up to 20% of Ixodid ticks can be coinfected with Borrelia burgdorferi and 1 or more other tick-borne human pathogens.^11-13

Molecular tests can be useful in detecting these organisms in early/acute stages of infection, when genetic material from the pathogen can be detected but antibodies remain below the limit of detection (LoD) of serologic assays.^2,11-13 Quest offers molecular and/or serological tests for B burgdorferi, B miyamotoi, A phagocytophilum, E chaffeensis, and B microti, individually (see Test Directory for individual test codes) and in 3 panels: 

• Tick-borne Disease, Antibody Panel (test code 36942): Includes A phagocytophilum IgG, IgM (34464); B duncani (WA1) IgG (17231); B microti IgG, IgM (34300); Lyme Disease Ab w/ Reflex to Blot (6646); E chaffeensis IgG, IgM (34271)
• Tick-borne Disease, Acute Molecular Panel (test code 94322): Includes real-time PCR-based tests for A phagocytophilum DNA (17320); B microti DNA (37314); B miyamotoi DNA (93795); E chaffeensis DNA (11353); Lyme Disease (Borrelia spp) DNA, Blood (15777)
• Tick-borne Disease, Acute Molecular Panel, Non-Lyme (test code 32338): Includes real-time PCR-based tests for A phagocytophilum DNA (17320); B microti DNA (37314); B miyamotoi DNA (93795); E chaffeensis DNA (11353)

Click here for a list of additional tests available from Quest for tick-borne diseases.