Annual and monthly communicable disease surveillance reports for Toronto are currently unavailable online in PDF format. To receive a PDF copy of any report, please contact the Communicable Disease Surveillance Unit by phone 416-392-7411 or email during business hours Monday to Friday, 8:30 a.m. to 4:30 p.m. We apologize for any inconvenience.

A summary of reportable communicable disease data for the City of Toronto for 2017 (the most recent calendar year for which data are available) is posted on the page: Communicable Diseases in Toronto. For each disease, a comparison to the previous five-year period is included.

Additional data and information on communicable disease trends and activities in Ontario and Toronto can be accessed via Public Health Ontario, including:

Current reportable disease trends in Toronto are summarized in this report. To allow adequate time for reports to be processed, and for investigations and quality assurance checks to be completed, data are posted with a delay of approximately two months. Updated data are published monthly around the middle of the month, and can be accessed via the City’s Open Data portal. An additional resource is Public Health Ontario’s monthly report, linked below.

The weekly influenza bulletin is produced weekly during periods with increased influenza activity in Toronto – generally November to April – and provides descriptive epidemiologic data on influenza activity in the City of Toronto.

The full report is distributed each Friday, by email subscription.

Subscribe to Weekly Influenza News


Technical notes to accompany the Weekly Influenza News

Summary of Influenza Activity in Toronto: Week 49 (Dec 2, 2018 to Dec 8, 2018)

 Indicator Activity Level*  Description
Laboratory-Confirmed Influenza Cases Comparable In week 49, 28 new laboratory-confirmed cases of influenza were reported, comparable to the 24 cases reported in week 48. To date this season, 120 cases have been reported, higher than the previous 5-season mean of 103 cases.
Influenza Strains for Ontario Cases 4 new isolates characterized As of week 48, the Ontario Respiratory Pathogen Bulletin reported 18 isolates for Ontario cases to date this season:

  • A/Michigan/45/2015, H1N1 (n=10)
  • B/Phuket/3073/13-like (n=8)
Influenza Outbreaks in Toronto Healthcare Institutions Higher One institutional influenza outbreak was reported in week 49.
Overall Comparable Influenza activity in Toronto for week 49 was comparable to week 48.

*May not reflect statistically significant changes, but describes overall observed trends and compares to the previous surveillance week.


Starting in the 2017/18 season, the Ontario Ministry of Health and Long-Term Care advised public health units that they were no longer required to do any additional investigation to collect information beyond what has already been reported in the initial laboratory report. No changes were made to investigation of institutional influenza outbreaks. As a result, subtype information will be available for a smaller proportion of laboratory-confirmed cases, and hospitalization and death information will be underestimated. Therefore, comparisons between the current season and prior seasons should be made with caution.  Please refer to the technical notes for details.


Data on influenza strains for Ontario cases are obtained from the Ontario Respiratory Pathogen Bulletin published the week preceding the current Weekly Influenza News for Toronto (e.g. for the Weekly Influenza News for week 34, the influenza strains data are obtained from the Ontario Respiratory Pathogen Bulletin published for week 33).

Additional Data and Information for Ontario and Nationally