MEMO: Changes to Lyme Disease Testing, Updated Resources and Reporting Tools

TO:   Physicians and Nurse Practitioners in Niagara

FROM: Niagara Region Public Health, Infectious Disease Program

REFERENCE: Changes to Lyme Disease Testing, Updated Resources and Reporting Tools

DATE: April 3, 2023

This memo is to inform you that the Public Health Ontario Lab (PHOL) will be moving to a different testing algorithm for Lyme disease.

As of April 1, 2023, PHOL will begin testing patient samples for Lyme disease antibodies using a new method known as the Modified Two-Tier Testing (MTTT) instead of Standard Two-Tier Testing (STTT). In this method, initial screening will continue to be performed by IgG/IgM ELISA and samples that are reactive or indeterminate will be further tested using a second ELISA (rather than a Western Blot as was the process in STTT).

MTTT, which has been evaluated by PHOL and endorsed by the Canadian Public Health Laboratory Network and US Centres of Disease Control and Prevention, provides 15-25% higher sensitivity during early-localized disease, and comparable sensitivity during early-disseminated and late-disseminated disease compared to STTT. The MTTT algorithm has also shown comparable specificity to STTT.

Implications for Practice

• Changes in testing algorithm will support a clinical Lyme disease diagnosis, particularly in the early localized stage of the disease (by reducing the chances of a false negative result) and improve the turnaround time for Lyme disease testing and earlier intervention
• Updated PHOL resources can be found on their website
• If you have questions about these changes contact PHOL
  • Email: customerservicecentre@oahpp.ca
  • Call: 416-235-6556

Updated Clinical Guidance Resource

• Ontario Health has recently updated their clinical guidance resource addressing the diagnosis and treatment of early localized Lyme disease. The resource provides health care providers with information on the management and investigation of early localized Lyme disease, based on the best available evidence.
• Access the updated resource here

Updated Reporting Tools for Lyme Disease

• Niagara Region Public Health (NRPH) has recently updated the Lyme disease reporting tools. Lyme disease can be reported to NRPH online or by fax.
  • To report online, complete our web form
  • To report by fax, complete this form. Please discard any past versions of this form you may have.