COVID-19

• COVID-19 Weekly Update - July 8/21​
• COVID-19 Weekly Update - June 24/21​​
• COVID-19 Weekly Update - June 17/21​

• Weekly Detailed Epidemiological Report - July 19-25, 2021​​​

Definitions & Terms

Overview

​Northwestern Health Unit (NWHU) receives lab confirmation about COVID-19 cases when testing is complete. Before sharing this information with media or posting it to our website, we have to be sure of the facts.

Updated weekdays by 1pm.

Case data are derived from the Ministry of Health Case & Contact Management (CCM) system, which is the official source for COVID-19 statistics in the province.  There may be times when the COVID-19 statistics on the Ministry’s website do not match those reported by NWHU because updates take place at different times of the day.  Data are being entered into CCM continuously, and may be amended as new information becomes available.

During the week, our reports are based on the data in CCM.  On weekends, our reports may also be based on lab results that we receive, incoming reports from other jurisdictions, and any information that has been entered into CCM.  Because we use multiple sources of information on the weekends, we need to reconcile the statistics during the week to ensure that no duplicate cases were reported, or cases missed.  This explains why reported values may not correspond to notices sent out on the weekends.

When NWHU receives a new positive test result, case investigation and contact tracing begins immediately. This allows us to confirm the test result, make sure that the person with COVID-19 knows how to take care of themselves and protect others from infection, and to identify others who might be at risk.  As soon as possible afterwards, NWHU enters case information into CCM.

All data in this report pertains to cases that are confirmed positive for COVID-19.  Any cases currently considered ‘probable’ for COVID-19 may be included in future reports if they are subsequently confirmed with positive test results.

“Active Cases” that appear in brackets refer to cases who have a permanent residence outside of the NWHU region, but are currently located within our catchment area.  These cases are not counted as part of NWHU’s confirmed case count, as they are recorded within the region of their home address.  NWHU conducts contact tracing and monitoring of self-isolation for all cases within our region, including anyone who is here temporarily or not currently identified as a permanent resident.

“Resolved Cases” include the number of individuals with confirmed COVID-19 whom public health considers recovered from their illness plus the number of deaths among individuals in which COVID-19 was determined to be a contributing or underlying cause of death. 

Cases assigned as “Other” have a primary residence outside of the NWHU region and have not been to the NWHU region.  Occasionally old addresses are used on lab requisitions and cases are assigned to a health unit based on their previous area of residence.

“Hospitalized” refers to cases with a hospital intervention due to COVID-19 as indicated in CCM.

“Deaths” reported include those who had COVID-19 at time of death but died of another cause.

“Outbreaks” reflect the following definitions at the time they were declared open:

Hospitals:  2 staff or patient cases of laboratory-confirmed COVID-19 within a specified hospital unit within a 14-day period where both cases could have reasonably acquired their infection in hospital is considered an outbreak in a public hospital.

Long Term Care Homes:  1 staff or resident case of laboratory-confirmed COVID-19 is considered an outbreak in long-term care homes (LTCH), retirement homes (RH) and other healthcare institutions (e.g. group home, assisted living, group shelter) and declared facility wide.

Schools:  2 student or staff (or visitor) cases of laboratory-confirmed COVID-19 within a specified class within a 14-day period where at least one case could have reasonably acquired their infection at school (including transportation and before/after school care) is considered an outbreak in an educational establishment.

Daycares:  1 child or staff (or household member) case of laboratory-confirmed COVID-19 is considered an outbreak in a childcare establishment.

For more information:

COVID-19 cases in schools and daycares: https://www.ontario.ca/page/covid-19-cases-schools-and-child-care-centres​

 Vaccination Statistics 

Our statistics include vaccines administered with NWHU listed as the authorizing organization within the provincial database.     

“Eligible age groups” are determined by vaccine types, characteristics, and availability. Younger age groups will be added as applicable vaccine supply becomes available. Accordingly, the size and characteristics of groups that are considered eligible may vary. Currently, eligible age groups include anyone 12 years of age or older, to be consisent with Provincial data.  

Population size estimates of the NWHU catchment may vary by 13% or more depending on the information source (i.e. Statistics Canada, IntelliHealth Ontario etc.) and characteristics of data gathering.  These estimates have proportional differences among them including 'people in different age groups', and 'people in different sociodemographic groups including race'.  These differences can result in significant reporting variances among different organizations and reports.   Currently, the largest and most current total population estimates from IntelliHealth Ontario are used on the NWHU website.  Accordingly, reporting of vaccination estimates may not reflect those from other sources that utilize population parameters from different sources.  Estimates with lower population totals (including Statistics Canada) have the potential to over-report vaccination percentages in certain cases.  

As with population estimates for any region, the total number of people living on-reserve, including proportions in different age & socioeconomic groups, may differ according to the information source and methods of information gathering.  NWHU uses the most recent and reputable estimates available that pertain to population size of 'on-reserve' communities.  We will incorporate newer and more accurate data if or when it becomes available.  

Vaccine data reporting differences: Why might inconsistencies appear to occur?   

Over time changes in eligible groups and population parameters will occur, and NWHU incorporates this information at the time of reporting.  The data for many eligible individuals may not be currently available to the NWHU via partner organizations or provincial databases.  As these data become available, those numbers will be included in our analysis, resulting in increases or decreases in performance numbers based on the completeness of the data available.  The ultimate goal of the NWHU is to make sure that every eligible person receives a vaccine if they want one, and this means adapting metrics as new information sources become available. In some circumstances this will result in changes to reported statistics.  When numerical parameters offer estimates within a range of values, NWHU may tend to adopt conservative values to avoid shortages in dose allocation.  Progress rates may decline in times when individuals from small remote communities are being vaccinated: this is because although it is important to make the time and resources available to vaccinate these communities, they account for a very small fraction of the entire population.   

Timeliness of Reports:  Reporting time depends in part on data access and availability.  Provincial databases can, at times, be unavailable for various reasons including maintenance downtime and bandwidth availability.  NWHU will issue late reports immediately after regaining data access that was temporarily unavailable. 

Test Results

Updated Mondays by 1pm. Data Source: Ontario Laboratories Information System (OLIS). Test restults are grouped according to the primary residence address provided by the individual at time of testing.

Tests per 100,000 people’ refers to the number of tests done per every 100,000 people living in each region.  This is calculated by dividing the total number of tests done by the most recent population estimate, then multiplying that number by 100,000.  A higher testing rate indicates that a greater proportion of the population has been tested.

‘Positivity Rate’ (or Percent Positivity) refers to the percentage of tests completed which were positive for COVID-19.  This is calculated by dividing the number of positive tests by the total number of tests completed, then multiplying by 100 to obtain a percentage.  A lower percent positivity indicates that more people are being tested who are not infected.  Percent positivity is used to monitor the community infection rate.

 Reporting Geography

Public Health Units comply with the Personal Health Information Protection Act (PHIPA), and cannot publicly release information that can identify individuals with COVID-19.  When case data released by NWHU & the province is combined with a specific location, it can allow a person to be identified because of our small population and geography. 

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NWHU is normally under a legal obligation to group cases using up to 4 regions in the catchment area.  We are presently able to report by 8 ‘health hubs’ instead of by 4 larger regions.  Legal compliance is preserved because case numbers are high enough that information released by the Ministry cannot be linked to the cases we announce.

Supplementary Data Resources