- 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.
Smallpox
Smallpox is a contagious disease caused by the variola virus. The disease was eliminated globally as a result of vaccination, with the last naturally occurring case occurring in 1977. Smallpox was transmitted from person-to-person through contact with smallpox sores and through coughing or sneezing.
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 smallpox by year
More information about smallpox
Merck Manual
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 smallpox 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 smallpox?
Contact the Health Unit.
Exclusion is required, but the length is assessed on an individual case basis.
Smallpox is preventable by vaccination however routine immunization of the general Canadian population is not recommended.
Healthcare provider information
Smallpox immunization of the general Canadian population is no longer recommended. Refer to the chapter Smallpox and mpox vaccines of the Canadian Immunization Guide for more information.
Once a person shows symptoms, treatment is limited to supportive therapy and antibiotics to treat secondary bacterial infections.
Infection prevention and control
Airborne and contact precautions are required in addition to routine practices. Refer to Appendix N: Clinical Syndromes/Conditions with Required Level of Precautions and Public Health Ontario’s Best Practices for Routine Practices and Additional Precautions for more information.
In the event of a suspected case, immediately contact the Public Health Ontario Laboratory (PHOL) Customer Service Centre at 1-877-604-4567 or the after-hours Duty Officer at 416-605-3113. PHOL medical and clinical microbiologists will provide advice prior to sampling. PHOL can assist with arranging safe transportation of clinical specimens to the National Microbiology Laboratory.
Post-exposure prophylaxis (PEP)
Administering Smallpox vaccination within four days of exposure can ameliorate illness in nearly all cases of smallpox exposure. Refer to the chapter Smallpox and mpox vaccines of the Canadian Immunization Guide and Smallpox and other Orthopoxviruses including mpox (Ministry of Health, 2024) for more information.
Merck Manual Professional version
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: July 2026, by CDC