TBDHU COVID-19 Weekly Status Update

Written by Thunder Bay District Health Unit on 12 October 2021

Updated October 12, 2021; includes data up to October 9, 2021

TBDHU COVID-19 Response Indicators

The following indicators, among several others, are monitored by local public health officials and the Ontario government regularly to ensure the appropriate public health measures are being taken against COVID-19.

This refers to the rate of confirmed cases of COVID-19 per every 100,000 people living in TBDHU. This is calculated by dividing the total number of confirmed cases of COVID-19 reported during the specified period by the TBDHU population, then multiplying by 100,000. Note that rates based on fewer than 20 cases are unstable, meaning that a small change in the numerator can lead to a large change in the rate from one week to the next. Note that the calculated values in the above graph may differ slightly from provincial calculations due to slight differences in methodology and data sources.
This reflects the average percent positivity among tests done during the specified 7-day period only. This indicator helps understand the current community infection situation. To view trends since the beginning of the pandemic and compare to Ontario, view the graph below.
This indicator helps monitor whether the public health system capacity is adequate or becoming overwhelmed. Timely follow-up by public health and completion of a thorough case investigation is essential to contain the transmission of COVID-19.

TBDHU incidence rate over time¹

This refers to the rate of confirmed cases of COVID-19 per every 100,000 people living in TBDHU. This is calculated by dividing the total number of confirmed cases of COVID-19 reported during the previous 7 days by the TBDHU population, then multiplying by 100,000. Note that rates based on fewer than 20 cases are unstable, meaning that a small change in the numerator can lead to a large change in the rate from one week to the next. Note that the calculated values in the above graph may differ slightly from provincial calculations due to slight differences in methodology and data sources.

Variants and Mutations

TBDHU COVID-19 cases with variants and mutations, by type and lab reported date

Cumulative TBDHU COVID-19 cases with variants and mutations by type, through Oct 9, 2021

B.1.1.7(Alpha): includes all cases where lineage B.1.1.7 was identified through Whole Genome Sequencing (WGS) and those presumed B.1.1.7 based on mutations .B.1.617.2 (Delta): includes all cases where lineage B.1.617.2 was identified through WGS. Presumed Delta: includes cases presumed to be B.1.617.2 (Delta) based on mutation testing results for cases lab reported on or after August 26, 2021. Note that cases in this category may be moved into the B.1.617.2 (Delta) category if they are sent for WGS.Other VOCs and mutations: includes P.1 (Gamma), B.1.351 (Beta) and other cases which had mutation(s) detected but did not undergo WGS and based on their mutation results could not be presumed Alpha or Delta.Lab reported date: the date the initial positive result was reported to public health.
PHO began testing for variants and mutations for cases reported on or after February 7, 2021. As of March 22, all eligible COVID-19 positive specimens are tested for the N501Y and E484K mutations. Not all eligible COVID-19 positive specimens are sent for WGS. On August 26, 2021, PHO reduced the proportion of samples sent for WGS. Variant and mutation testing occurs after the positive result is reported to public health. Mutation results are reported within 3 days of the initial lab report. If performed, WGS results are reported within 2 to 4 weeks of the initial lab report. The variant and mutation data on this page only includes cases in which mutation testing and/or WGS was performed. Not all cases are eligible for mutation or WGS testing. For more details about VOC surveillance in Ontario, visit Public Health Ontario’s VOC Surveillance page.

Testing Data

7-day average percent positivity over time¹

This reflects the average percent positivity among tests collected during the previous 7 days since Oct 1, 2020. This indicator helps understand the current community infection situation. Note that the data on starred dates is not considered complete (all tests collected these dates may not yet be reported).

Testing Indicators over time`¹

The testing rates in this graph are 7-day averages. This means the indicator on a given day represents its average over the past 7 days. This allows for a ‘smoother’ curve and more visible trends. The x-axis dates are represent the collection dates. Note that the data on starred dates is not considered complete as all tests collected these dates may not yet be reported when extracted.

Cumulative Testing Indicators

This refers to the number of tests done since the beginning of the pandemic per every 100,000 people living in the area. This is calculated by dividing the total number of tests done by the population of the area, then multiplying that number by 100,000. A higher testing rate indicates that a greater proportion of the population has been tested.
This refers to the percentage of tests done since the beginning of the pandemic which were positive for COVID-19. This is calculated by dividing the number of positive tests by the total number of tests done, then multiplying by 100 to obtain a percentage. A lower percent positivity indicates that more people are being tested who are not infected than people who are. Percent positivity can be used to monitor the community infection rate.

The testing data in this dashboard excludes tests for persons with a blocked Ontario health card number or who do not have an Ontario health card, therefore it may under-estimate true counts.

Sources: Ministry of Health, 2021, extracted from Ontario Laboratory Information Systems (OLIS);Ontario Case and Contact Management tool (CCM), 2021

*For a list of additional sources, click here (scroll to bottom of weekly update)