From the Guidelines
The recommended blood tests for Lyme disease involve a two-step process: first, an enzyme immunoassay (EIA) or immunofluorescence assay (IFA), followed by a Western blot test if the first test is positive, as stated in the guidelines by the Infectious Diseases Society of America 1.
Diagnosis and Treatment
The diagnosis of Lyme disease requires serologic analysis to confirm the diagnosis, but proper interpretation depends on symptoms and timing of illness 1.
- For early localized Lyme disease, doxycycline (100 mg twice daily for 10-14 days) is the preferred antibiotic for adults and children over 8 years old 1.
- Alternatives include amoxicillin (500 mg three times daily) or cefuroxime axetil (500 mg twice daily) for the same duration, which are also used for pregnant women and children under 8 1.
- For early disseminated or late Lyme disease, the same antibiotics may be used but for 14-21 days 1.
- In cases of Lyme carditis or neurological involvement, intravenous antibiotics like ceftriaxone (2 g daily for 14-28 days) may be necessary 1.
Importance of Prompt Treatment
Treatment should begin promptly after diagnosis to prevent progression to later stages 1.
- The two-step testing approach helps confirm infection by detecting antibodies against Borrelia burgdorferi, the bacterium causing Lyme disease, while antibiotics work by eliminating the infection before it can cause more serious complications 1.
- It is essential to note that the sensitivity of the two-step testing approach is low (30%–40%) during early infection, but specificity is high (>95%) during all stages of disease 1.
From the Research
Blood Tests for Lyme Disease
- The Centers for Disease Control and Prevention (CDC) recommends a two-tiered approach to testing, consisting of initial IgM and IgG quantitative enzyme-linked immunosorbent assay (ELISA), followed by confirmation of all indeterminate or positive ELISA tests with separate IgG and IgM Western blots 2.
- The two-test protocol relies on a sensitive screening test, which is followed by specific immunoglobulin M (IgM) and/or IgG immunoblotting (IB), depending on the date of disease onset, of all samples with equivocal and positive screening test results 3.
- Other testing modalities currently under evaluation include IgG vlsE C6 peptide ELISA, other two-tiered testing strategies, rapid diagnostics, and PCR 2.
Treatment for Lyme Disease
- There is no specific information on treatment for Lyme disease in the provided studies, however, it is known that treatment typically involves antibiotics.
Sensitivity and Specificity of Blood Tests
- The sensitivity and specificity of the ELISA were determined to be 96 and 100%, respectively, compared with the reference data provided for these specimens 3.
- The assay sensitivity and specificity were 80 and 96.2%, respectively, for IgM and 81.8 and 95.8%, respectively, for IgG 3.
- The clinical sensitivity and specificity for all study subjects were determined to be 50 and 100%, respectively 3.
- A prospective study found that with 2-tier tests and the C6 peptide ELISA, only approximately one-third of 76 patients with erythema migrans had results that were positive for IgM or IgG seroreactivity with Borrelia burgdorferi in acute-phase samples 4.
New Technologies and Diagnostic Testing
- New technologies examine early immune responses to Borrelia burgdorferi and have the potential to diagnose Lyme disease in the first weeks of infection when existing serologic testing is not recommended due to low sensitivity 5.
- In 2019, the Food and Drug Administration approved a modified 2-tier test strategy using 2 EIAs, offering a faster, less expensive, and more sensitive assay compared with standard 2-tier testing 5.