American Society for Microbiology

View all recommendations from this society

August 5 2020

Do not order a Lyme immunoblot without a positive Lyme Enzyme immunoassay (EIA) screening test.

The Lyme immunoblot test is designed only as a confirmatory test, so it is important not to test screen-negative samples. Some antigens on the blot react with non-Lyme antibodies, and the immunoblot can be over-interpreted in the absence of a positive screening test. Current 2-tiered serology has a sensitivity of 70%–100% and specificity >95% for disseminated Lyme disease; use of an immunoblot without a positive screening test is unwise. While the exact characteristics of current immunoblot tests used alone are not well-defined, high false positive IgM rates have been observed in patients tested without a prior EIA.

This recommendation assumes that a patient has had the potential for contact with ticks in an endemic area.

These items are provided solely for informational purposes and are not intended as a substitute for consultation with a medical professional. Patients with any specific questions about the items on this list or their individual situation should consult their physician.
American Society of Microbiology in partnership with the Five Things Physicians and Patients Should Question

How The List Was Created

The American Society for Microbiology’s (ASM) list was developed under the leadership of the ASM’s Clinical and Public Health Microbiology Committee. The subject matter experts who identified the list and formulated the recommendations are laboratory directors at academic, commercial and public health laboratories and test utilization experts across the fields of microbiology and laboratory medicine. They worked together to identify a list of diagnostic and management decisions that have resulted in misuse of laboratory studies and resources. The five experts independently ranked the recommendations in order of priority and identified tests or procedures commonly used whose necessity should be questioned and discussed with patients. The experts formulated recommendations based on laboratory practice, evidence and an extensive review of the literature.

Five recommendations to address the most common clinical microbiology laboratory test misconceptions were written. They consist of diagnostic tests or treatments that are commonly ordered, expensive and have no evidence to illustrate its value and in some cases, may be potentially harmful to the patient. The recommendations, if instituted, would result in higher quality care, lower costs, and more effective use of our laboratory resources and personnel. The experts involved in this project are Sheldon Campbell, Marc Couturier, Omai Garner, Duane Newton, Preeti Pancholi and Linoj Samuel.

The recommendations were vetted and approved by ASM’s Clinical and Public Health Microbiology Committee.

The list has also been reviewed and approved by the ASCP Effective Test Utilization Committee.


Moore A, Nelson C, Molins C, Mead P, Schriefer M. Current Guidelines, Common Clinical Pitfalls, and Future Directions for Laboratory Diagnosis of Lyme Disease, United States. Emerg Infect Dis. 2016 Jul;22(7).

Lantos PM, Rumbaugh J, Bockenstedt LK, Falck-Ytter YT, Aguero-Rosenfeld ME, Auwaerter PG, Baldwin K, Bannuru RR, Belani KK, Bowie WR, Branda JA, Clifford DB, DiMario FJ Jr, Halperin JJ, Krause PJ, Lavergne V, Liang MH, Meissner HC, Nigrovic LE, Nocton JJJ, Osani MC, Pruitt AA, Rips J, Rosenfeld LE, Savoy ML, Sood SK, Steere AC, Strle F, Sundel R, Tsao J, Vaysbrot EE, Wormser GP, Zemel LS. Clinical Practice Guidelines by the Infectious Diseases Society of America, American Academy of Neurology, and American College of Rheumatology: 2020 Guidelines for the Prevention, Diagnosis, and Treatment of Lyme Disease. Neurology. 2021 Feb 9;96(6):262-273.

CDC Lyme Disease Resources:

Wormser GP, Dattwyler RJ, Shapiro ED, Halperin JJ, Steere AC, Klempner MS, Krause PJ, Bakken JS, Strle F, Stanek G, Bockenstedt L, Fish D, Dumler JS, Nadelman RB. The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006 Nov 1;43(9):1089-134.

Seriburi V, Ndukwe N, Chang Z, Cox ME, Wormser GP. 2012. High frequency of false positive IgM immunoblots for Borrelia burgdorferi in clinical practice. Clin Microbiol Infect 18:1236–1240