- 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.
PSP
Paralytic Shellfish Poisoning
Paralytic shellfish poisoning (PSP) is caused by ingesting a toxin found in mussels, oysters, or clams from water where the toxin is present. Signs and symptoms typically begin between 30 minutes and three hours after eating the contaminated food. The toxins that cause PSP are not destroyed by cooking. People can reduce their risk of poisoning by only buying shellfish from reputable sources.
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 paralytic shellfish poisoning by year
Report to the Health Unit within one business day by fax (705-482-0670) or phone at 705-474-1400 or toll free at 1-800-563-2808, ext. 5229 if paralytic shellfish poisoning 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.
Should one go to childcare, school, or work if they have PSP?
No exclusion necessary as it is not spread form person-to-person.
Healthcare Provider Information
Public Health Ontario
Ministry of Health - Ontario Public Health Standards
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: February 2025, by CDC