Outbreaks in healthcare and congregate institutions:

Definitions:

• Number of new respiratory outbreaks declared in healthcare and congregate settings in the past week. Includes COVID-19, influenza, and other respiratory outbreaks (including respiratory syncytial virus outbreaks).
• Number of new enteric outbreaks declared in healthcare and congregate settings in the past week. Includes rotavirus, norovirus, and other enteric outbreaks.

Data sources:

• COVID-19 outbreaks: The Ministry of Health’s Public Health Case and Contact Management (CCM) solution up to June 1, 2024 and in the Ministry of Health’s integrated Public Health Information System (iPHIS) from June 2, 2024 onwards.
• Influenza, RSV, other respiratory outbreaks, and enteric outbreaks: Ministry of Health’s iPHIS

Data considerations: Outbreak definitions change over time. Outbreaks were declared based on the definitions in place at the time.

Hospital bed occupancy

Definition: The average daily hospital occupancy count per week of people admitted to local hospitals due to infection of COVID-19, influenza, and/or respiratory syncytial virus (RSV).

Data source: Inpatient Data File (Hospital Bed Census) from the Ministry of Health (Capacity Planning and Analytics Division) SAS Visual Analytics Hub

Data considerations: Includes hospital admissions (including ICU admissions) to local hospitals, regardless of whether the patient is resident of RCD. Does not include emergency department visits. People may be counted in bed occupancy data for multiple days.

COVID-19 and influenza case counts and rates

Definition:
Number of COVID-19 or influenza cases reported in a given week. Rate calculated by dividing weekly case number by total population and multiplying by 100,000.

Data sources:

The methodology and data sources for counting COVID-19 and influenza cases have changed over time.
a) OLIS-derived cases: calculated using laboratory data obtained from the Ontario Laboratories Information System (OLIS) dataset. OLIS-derived case data are available from September 21, 2025 onwards for influenza and from June 2, 2024 onwards for COVID-19.
b) Public health unit (PHU) Reported (from the Ministry of Health’s integrated Public Health Information System (iPHIS)/the Public Health Case and Contact Management (CCM) system): calculated using provincial case definitions and captured by a public health unit in a disease reporting system. Data for confirmed influenza cases were previously obtained from iPHIS or via direct aggregate reporting. These data are available up to September 20, 2025. Data for COVID-19 cases were obtained from CCM up to June 1, 2024.

Data considerations: OLIS-derived cases and PHU reported cases should not be directly compared. Testing eligibility for COVID-19 changed throughout the pandemic.

Percent (%) positivity

Definition: Percent of all COVID-19 molecular tests, influenza tests, or RSV tests processed in a given week which have a positive result.

Data source: Ontario Laboratories Information System (OLIS) from the Ministry of Health (Capacity Planning and Analytics Division) SAS Visual Analytics Hub

Data considerations: Includes reports submitted to the Ontario Laboratory Information System (OLIS). Does not contain consent blocked records or those records for which a health card number could not be determined. Not all laboratories report to OLIS. Does not include results from rapid antigen tests (RAT) tests.

Respiratory-related emergency department (ED) visits

Definition: Percentage of all ED visits by RCD residents that are specifically for respiratory-related concerns in the past week (syndrome = RESP).

Data source: The Acute Care Enhances Surveillance Application (ACES), KFL&A Public Health

Data considerations: Includes data from most local emergency departments and non-local emergency departments that RCD residents may visit. ACES uses natural language processing to scan the words or phrases included in the “chief complaint” or “reason for admission” and to sort the records into “syndromes”. Monitoring syndromes in real time can identify an outbreak or public health concern much faster than is possible using laboratory results, but syndromes are not clinical diagnoses and therefore need to be interpreted with care.

Population estimates for RCD

Data sources:

• 2020-2024: Statistics Canada. Table 17-10-0157-01: Population estimates, July 1, by health region and peer group, 2023 boundaries
• 2025-present: Population Reporting. Population projections public health unit, 2024-2051 [data file]. Toronto ON: Ministry of Finance [producer]; Toronto, ON: Ontario. Ministry of Health, IntelliHealth Ontario [distributor]; [data extracted 2025 Sep 12].