- Case counts (2016-2025), population estimates (2016-2023), & population projections (2024-2025): Public Health Ontario.
- Query: Case counts of reportable diseases by public health unit and year. Toronto, ON: Ontario Agency for Health Protection and Promotion; extracted on March 9, 2026.
Plague
Plague is a disease caused by the Yersinia pestis bacterium which can infect both animals and humans. There are three forms of plague: bubonic plague, septicemic plague, and pneumonic plague.
Bubonic plague is the most common form. It usually occurs from the bite of an infected flea that has fed on an infected rodent, such as a rat.
Septicemic plague can occur when the infection spreads through the blood. This type of plague can cause bleeding and shock. It is usually a complication of bubonic plague.
Pneumonic plague is the most serious form. Most of the symptoms are due to the infection occurring in the lungs. It is the only form of plague that can be spread from person to person by droplets in the air. Symptoms of pneumonic plague can appear as soon as 1 day after the lungs are infected with the bacterium. Untreated pneumonic plague is almost always fatal.
Local Information
2025 Statistics
Incidence rate is the number of new cases of disease divided by the number of persons at risk for the disease during a particular time period.
Cases:
0*
Incidence rate per 100,000 in 2025: 0
*Includes confirmed cases in 2025.
Incidence rate per 100,000 of plague by year
Public Health Agency of Canada
Report to the Health Unit immediately by fax (705-482-0670) and phone at 705-474-1400 or toll free at 1-800-563-2808, ext. 5229 if plague is suspected or confirmed as per Ontario Regulation 135/18 and amendments under the Health Protection and Promotion Act, R.S.O., c.H.7.
After hours, weekends, and holidays, call 705-474-1400 then press 0 to speak with the Answering Service. The on-call CDC Public Health Nurse will get back to you as soon as possible.
Should one go to childcare, school, or work if they have plague?
Exclusion and strict isolation are required for those with pneumonic plague until 48 hours of appropriate antibiotic treatment has been completed, then return once feeling well enough to participate in regular activities. For other types of plague, contact the Health Unit.
At this time, there is no plague vaccine available in Canada for travellers.
Healthcare provider information
Infection prevention and control
In healthcare settings, individuals with pneumonic plague must be isolated on droplet precautions until it has been 48 hours from the start of effective treatment.
Public Health Ontario
Public Health Ontario
Ministry of Health - Ontario Public Health Standards
Public Health Agency of Canada
Contact our Communicable Disease Control (CDC) program at 705-474-1400 or toll free at 1-800-563-2808, ext. 5229, or by email to cdc@healthunit.ca for more information.
Last updated: Apr 2026, by CDC