Event Details

Canada maintained measles elimination for more than two decades, with transmission typically limited to short chains following importations. Beginning in late 2024, however, a multi-jurisdictional outbreak resulted in prolonged transmission, predominantly among under-vaccinated populations, and ultimately led to the loss of Canada’s measles elimination status.

This PHO Rounds will describe the epidemiology and transmission patterns of Canada’s largest measles outbreak in decades and examine factors that shaped its trajectory, including heterogeneous population immunity and the concentration of transmission within specific communities. Drawing on operational experience from the response, the presentation will explore how established outbreak control approaches, including vaccination, case and contact management, laboratory and genomic surveillance, interjurisdictional coordination, and community engagement, performed during sustained transmission. The session will conclude with lessons from the response and practical considerations for strengthening measles outbreak preparedness and response and informing approaches to other vaccine-preventable diseases in Canada.

Intended audience: Public health professionals with interest in communicable disease, public health physicians, nurses, and health care providers who are interested in outbreak management.

By the end of this session, participants will be able to:

• Describe the epidemiology and transmission patterns of Canada’s recent multi-jurisdictional measles outbreak.
• Identify factors that contributed to sustained measles transmission, including under-vaccination, heterogeneous population immunity, and transmission within specific communities.
• Apply lessons from the outbreak response to strengthen outbreak preparedness, response coordination, surveillance, vaccination, and/or community engagement strategies in their own public health practice.

Dr. Kaitlin Patterson, PhD, is a Senior Epidemiologist with the Public Health Agency of Canada’s Centre for Emerging and Respiratory Infections and Pandemic Preparedness. She has led the federal epidemiological response to Canada’s multijurisdictional measles outbreak since October 2024 and chairs the national Outbreak Investigation and Response Coordinating Committee. Her work focuses on outbreak epidemiology, surveillance, risk assessment, and interjurisdictional response coordination. Kaitlin previously worked with the Canadian Field Epidemiology Program and has supported responses to emerging and vaccine-preventable diseases across Canada. She holds a PhD in Epidemiology and International Development.

The opinions expressed by speakers and moderators do not necessarily reflect the official policies or views of Public Health Ontario, nor does the mention of trade names, commercial practices, or organizations imply endorsement by Public Health Ontario.

Public Health Ontario Rounds are a self-approved group learning activity (Section 1) as defined by the Maintenance of Certification Program of the Royal College of Physicians and Surgeons of Canada (RCPSC).

Other colleges, including the College of Family Physicians of Canada, Royal College of Dental Surgeons of Ontario and the Canadian Institute of Public Health Inspectors, may accept RCPSC accredited events on a per-hour basis. Please contact your relevant college should you have any questions.

In order to receive written documentation for Continuing Medical Education (CME) credits, please check "Yes" beside the question "Do you require CME credits?" on the registration form.

For more information or for a record of registration for other Continuing Education purposes, please contact capacitybuilding@oahpp.ca.

Public Health Ontario is committed to complying with the Accessibility for Ontarians with Disabilities Act (AODA). If you require accommodations to participate in this event, please contact 647-260-7100 or capacitybuilding@oahpp.ca.