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Data up to end of day on August 12, 2020

New Interactive Halton COVID-19 Dashboard:

Halton’s new interactive COVID-19 dashboard provides a summary of the current local situation and incorporates core epidemiological indicators of COVID-19 activity in Halton to date. Dashboard users can explore Halton’s COVID-19 data on overall case counts, case demographics, institutional outbreaks and lab testing. The dashboard can be accessed at halton.ca/covid19.

Also, please note that as of July 17, Halton Region Public Health is currently in the process of adopting a new provincial COVID-19 database. During this transitional period, all counts should be considered preliminary and are subject to change as information is reconciled.


   Cases over time

935

COVID-19 cases among Halton residents to date (852 confirmed + 83 probable)

30

COVID-19 cases currently active among Halton residents (29 confirmed + 1 probable)

Figure 1: COVID-19 cases, by episode date, Halton Region, Mar. 1-Aug. 12, 2020
Figure 2: Cumulative COVID-19 cases, by episode date, Halton Region, Mar. 1-Aug. 12, 2020
Figures 1 and 2 show the 935 COVID-19 cases among Halton residents reported by end of the day on August 12. All cases have been graphed according to their episode date, which is used to estimate the date that symptoms began. Figure 1 shows the number of new cases per day, while Figure 2 shows how cases have accumulated over time. Counts for the past 14 days should be interpreted with caution (indicated using the grey shaded area on the graph), since there is a delay between when a person becomes infected and when they develop symptoms, get tested and are reported as a case. Please note the large increase on April 11 is due to expanded testing and identification of COVID-19 among asymptomatic individuals at Mountainview Residence.

Individuals who are lab-confirmed cases are shown in green. Individuals who are probable cases are shown in orange. Probable cases are individuals presumed to have COVID-19 because they have symptoms of COVID-19 and are travelers returning from an affected area, have had close contact with a confirmed case, lived/worked in a facility experiencing a COVID-19 outbreak, or have indeterminate test results.
Figure 3: 7-day moving average of confirmed non-institutional COVID-19 cases, by collection date, Halton Region, Mar. 1-Aug. 12, 2020
For each day, Figure 3 shows the average number of new confirmed COVID-19 cases over the past seven days, including only those cases that are not staff or residents/patients associated with an outbreak in an institutional or congregate care setting. Cases have been graphed according to their collection date, which is the date that a sample was taken from them to be tested for COVID-19. The graph suggests that the average number of new cases per day was highest in late March/early April, with another increase in mid-May. Counts for recent days should be interpreted with caution (indicated using the grey shaded area on the graph), since there is a delay between when a person is tested and when their test results are reported to Public Health and entered into the system. 


   Case demographics

79

cases were residents or patients of an institution experiencing an outbreak (8% of all cases)

115

cases work in health care (12% of all cases)

Figure 4: COVID-19 cases, by age and sex, Halton Region, 2020
Figure 4 shows that by end of the day on August 12, the most COVID-19 cases were among Halton residents aged 40-59 (with 318 cases, or 34%). 509 cases (54%) were female.
Figure 5: COVID-19 cases, by municipality of residence, Halton Region, 2020
Figure 5 shows that by end of the day on August 12, the greatest number of COVID-19 cases were among residents of Oakville (with 309 cases, or 33%). Please note this figure shows counts, and therefore does not take into account the different population sizes or age structures of the four municipalities. Counts in municipalities can also be inflated by outbreaks that have occurred within institutions in their boundaries.


   Case exposure source

Figure 6: Percentage of COVID-19 cases, by primary exposure category and municipality of residence, Halton Region, 2020

Figure 6 shows the percentage of COVID-19 cases by primary exposure category for Halton’s four municipalities and for Halton overall. For Halton overall, by end of day on August 12, 366 cases (39%) had contact with a confirmed case that was believed to be the source of their infection. 309 COVID-19 cases (33%) had no known travel or contact history, and therefore were believed to have acquired the virus within Ontario, making them community cases. 146 (16%) were residents/patients or staff associated with an outbreak in an institutional, congregate care, or workplace setting. 111 cases (12%) had a history of travel that was believed to have been the source of their infection. These proportions vary by municipality, and three cases with exposure information pending have been excluded.

It is important to note that cases can have multiple exposures, and these data reflect only their primary exposure category based on information gathered during case investigation.


   Case follow-up

Figure 7: Percentage of COVID-19 cases reached by Public Health within one day of being reported, Halton Region, cases reported Aug. 5-11, 2020
Figure 8: Percentage of COVID-19 community contacts reached by Public Health within one day of being reported, Halton Region, cases reported Aug. 5-11, 2020

Figure 7 shows that 100% of Halton cases reported over the past seven days (Aug. 5-11) were reached by Halton Region Public Health within one day of being reported, which exceeds the provincial goal of 90%. Figure 8 shows that Halton Region Public Health reached 100% of contacts identified over the past seven days (Aug. 5-11) within one day, compared to the provincial goal of 90%.

It is important to note that Public Health attempted to reach 100% of cases and community contacts within one day but in some cases could not reach the client within that time span. Common reasons for not reaching clients within one day include incorrect phone number provided or client did not respond to repeated contact attempts.


   Case outcomes

99

cases who have ever been hospitalized to date (none listed as currently in hospital)

880


cases who are resolved

25

cases who have died to date (12 of the deceased were residents or patients of an institution experiencing an outbreak)


   Institutional outbreaks

21

confirmed institutional outbreaks of COVID-19 reported to Halton Region Public Health to date (none are ongoing)

Figure 9: COVID-19 institutional outbreaks, by date outbreak was declared, Halton Region, Mar. 1-Aug. 12, 2020
Figure 9 shows the 21 confirmed outbreaks of COVID-19 in Halton institutions reported by end of the day on August 12. Institutions are defined as long-term care homes, retirement homes and hospitals. All 21 of the outbreaks have resolved. Among the 21 confirmed institutional outbreaks reported to date, 13 (62%) have been in long-term care homes, seven (33%) have been in retirement homes and one (5%) has been in a hospital.


   Lab testing

>3,820

Halton residents were tested for COVID-19 within the past seven days of available data (Aug. 2-8)

>64,160

Halton residents are known to have been tested for COVID-19 to date

Figure 10: Number of people tested for COVID-19 and percentage of people tested who had positive results, by week, Mar. 1-Aug. 8, 2020, Halton
The green bars in Figure 10 show the number of Halton residents who were tested for COVID-19 each week, beginning the week of March 1-7. Data for the most recent week (Aug. 2-8) is incomplete due to reporting lags. The number of people tested decreased the week of May 17 compared to past weeks as mass testing of institutional residents was completed. The number of people tested then began to increase again, as the provincial government permitted more widespread testing.

The orange line in Figure 10 indicates the percentage of tested Halton residents who were positive for COVID-19. The percent positivity was highest the week of April 5-11, when 10.3% of Halton residents who were tested for COVID-19 had positive results. In the most recent week (Aug. 2-8), 0.3% of people testing for COVID-19 tested positive, although this number is subject to reporting delays.


   Comparison to Ontario

40,367

total confirmed COVID-19 cases reported in Ontario to date

Figure 11: Age-specific rates of COVID-19 (per 10,000 population), Halton Region and Ontario, 2020
Figure 11 shows age-specific rates of COVID-19 for Halton and Ontario. Rates take into account the population size of each age group to make it possible to compare between different areas. Halton's age-specific rates are currently significantly different from the provincial rates for all age groups. For example, Halton has 38.4 cases per 10,000 residents aged 80+, which is statistically significantly lower than the 89.0 cases per 10,000 residents aged 80+ in Ontario overall. It is important to note that these rates will fluctuate as numbers increase throughout the pandemic and that differences between age groups may reflect differences in the likelihood of developing symptoms and being tested.

Data limitations

Data sources

Halton case data: Case and Contact Management system (CCM), extracted at 7:00 AM on August 13, 2020, to reflect data entered by the end of the day on August 12, 2020

Halton lab testing data: Institute for Clinical Evaluative Sciences, Number of individuals who were confirmed positive for COVID-19, COVID-19 Testing Period: 15 Jan 2020 to 8 August 2020. Received on August 11, 2020.

Ontario case counts: Public Health Ontario, Epidemiologic Summary, COVID-19 in Ontario: January 15, 2020 to August 12, 2020, posted on August 13, 2020 to https://www.ontario.ca/page/2019-novel-coronavirus.

Denominators for Halton and Ontario age-specific rates: Population projections [2020], IntelliHEALTH Ontario, extracted on April 8, 2020.

Data notes

CCM is a dynamic disease reporting system which allows ongoing updates to data previously entered. As a result, data extracted from CCM represent a snapshot at the time of extraction and may differ from previous or subsequent reports. The data only represent cases reported to public health and recorded in CCM. As a result, all counts will be subject to varying degrees of underreporting due to a variety of factors, such as disease awareness and medical care seeking behaviours, which may depend on severity of illness, clinical practice, changes in laboratory testing, and reporting behaviours.

Figures 1 and 2 distinguish between lab-confirmed and probable cases. Probable cases are individuals presumed to have COVID-19 because they have symptoms of COVID-19 and are travelers returning from an affected area, have had close contact with a confirmed case, lived/worked in a facility experiencing a COVID-19 outbreak, or had indeterminate test results.All other figures and numbers include both confirmed and probable cases combined, except Figure 3, which uses confirmed cases only.

All data includes only individuals whose main usual residence is in Halton Region. 
Cases who have municipality information pending are excluded.

Active cases, resolved cases and deaths are a subset of total cases.
  • Cases are considered to be active if the case is open in CCM and not listed as resolved.
  • Case outcomes (resolved, deaths) reflect the latest available information reported to Halton Region Public Health and recorded in CCM by the extraction time.
  • Resolved cases are persons who have been discharged from isolation at 14 days after symptom onset if they did not have a fever and their symptoms were improving for at least 72 hours OR 14 days from when they were tested if they were asymptomatic. For cases with no significant improvement in symptoms, Public Health continues monitoring until the case meets resolution criteria and the case is closed in CCM. For cases in hospital, a test-based approach may be used and isolation is continued until 2 consecutive negative tests are obtained, at least 24 hours apart.
  • Deaths include any death that occurred among a person who tested positive for COVID-19, even if the death may not have been directly attributable to COVID-19.

In subsequent reports, counts in Figures 1-3 may increase as cases are added from past dates as individuals become symptomatic, get tested, and their results are reported to Halton Region Public Health, as well as any past results are added due to delayed data entry or new arrival of lab results.

Cases are considered to be patients or residents of an institution experiencing an outbreak if they are linked to a confirmed Halton institutional outbreak in CCM, and they are not known to be a staff person at the institution.

Cases are considered to work in health care if they are known to have an occupation that involves caring for patients, e.g. physician, nurse, occupational therapist, recreational therapist, chiropractor, paramedic, midwife, orderly, etc. Individuals who work in health care settings but do not provide direct care to patients (e.g. managers, cleaning staff) have not been included.

Exposure type is determined by examining the risk factor fields in CCM to determine whether a case travelled, was a resident/patient or staff member in an institution/congregate care setting/workplace experiencing an outbreak inside or outside Halton, was a contact of a case or neither. A hierarchy has been applied as follows:

  • Cases with episode date before April 1: Travel > Associated with any type of outbreak (institutional, congregate care, or workplace) in or outside of Halton > Close contact of a confirmed case > None of the above (indicating community acquisition) > Information pending.
  • Cases with episode date on or after April 1: Associated with any type of outbreak (institutional, congregate care, or workplace) in or outside of Halton > Close contact of a confirmed case > Travel > None of the above (indicating community acquisition) > Information pending.
It is important to note that cases can have multiple exposures, and these data reflect only their primary exposure category.

Differences between municipalities have not been assessed for statistical significance. Known cases reflect only individuals who were prioritized for testing prior to the expansion of testing in May, which means that differences between municipalities are currently difficult to ascribe to other factors.

Cases are considered to have been reached within 24 hours if their investigation start date and case reported dates in CCM are no more than one day apart.

Contacts are considered to have been reached within 24 hours if their interview completion date and reported dates in CCM are no more than one day apart.

Our main priority in outbreak management is prevention. Ensuring appropriate measures are being taken by the institutions requires time, in addition to collecting information on the status of the residents. Institutional outbreaks include outbreaks of COVID-19 in settings such as long-term care homes, retirement homes, hospitals and prisons. Outbreaks in congregate care settings (e.g. group homes) and workplaces are not included. Date declared for outbreaks reflects the outbreak classification date in CCM.

Lab testing data reflects only lab tests that have been assigned to Halton Region based on the methodology used by the Institute for Clinical Evaluative Sciences. There are several known limitations associated with this data:

  • The unit of analysis is the testing episode (unique individuals tested per day). Individuals tested multiple times on different days are counted once in each week’s counts for the appropriate weeks. Testing episodes after the individual's first confirmed positive COVID-19 test were excluded from subsequent weekly counts (numerator and denominator).
  • The COVID-19 test results were captured in the Ontario Laboratories Information System (OLIS). The testing date represents the date of specimen collection: “observation date” in OLIS. Due to the time required for transportation and processing of specimens, it takes six days for approximately 95% of results to be finalized and reported for a given testing date. Some laboratories did not report all or part of their COVID-19 test results to OLIS. Unconsented test results were excluded;
  • Counts less than six are suppressed;
  • The location of tested individuals was based upon the test recipient’s postal code (and corresponding health unit) recorded in the OHIP Registered Persons Database (RPDB) for those residing outside a long-term care (LTC) facility, and the LTC address on the OLIS test requisition for specimens collected from LTC facilities. These address assignments lead to misclassification of PHU in approximately 14% of individuals

 

For daily Halton case tables and up-to-date information about how to protect yourself and others, please visit halton.ca/covid19

For daily provincial epidemiologic summaries and more information on COVID-19 in Ontario, please visit Ontario.ca/coronavirus

For national information on COVID-19 in Canada, please visit Canada.ca/coronavirus
Copyright © 2020 Halton Region Health Department, All rights reserved.


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