Data up to end of day on July 15, 2020
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Please note that the province will be transitioning Halton Region Public Health to a new provincial COVID-19 database on Friday, July 17. The weekly report will not be released next week as we adapt our reporting processes to this new data source. Thank you for your understanding.
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Cases over time
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COVID-19 cases among Halton residents to date (801 confirmed + 84 probable)
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COVID-19 cases currently active among Halton residents (38 confirmed + 3 probable)
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Figure 1: COVID-19 cases, by episode date, Halton Region, Mar. 1-Jul. 15, 2020
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Figure 2: Cumulative COVID-19 cases, by episode date, Halton Region, Mar. 1-Jul. 15, 2020
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Figures 1 and 2 show the 885 COVID-19 cases among Halton residents reported by end of the day on July 15. 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.
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Figure 3: 7-day moving average of confirmed non-institutional COVID-19 cases, by collection date, Halton Region, Mar. 1-Jul. 15, 2020
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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.
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Case demographics
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cases were residents or patients of an institution experiencing an outbreak (9% of all cases)
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cases work in health care (13% of all cases)
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Figure 4: COVID-19 cases, by age and sex, Halton Region, 2020
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Figure 4 shows that by end of the day on July 15, the most COVID-19 cases were among Halton residents aged 40-59 (with 308 cases, or 35%). 491 cases (55%) were female.
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Figure 5: COVID-19 cases, by municipality of residence, Halton Region, 2020
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Figure 5 shows that by end of the day on July 15, the greatest number of COVID-19 cases were among residents of Oakville (with 293 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.
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Case exposure source
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Figure 6: Percentage of COVID-19 cases, by primary exposure category and municipality of residence, Halton Region, 2020
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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 July 15, 352 cases (40%) had contact with a confirmed case that was believed to be the source of their infection. 291 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. 141 (16%) were residents/patients or staff associated with an outbreak in an institutional, congregate care, or workplace setting. 99 cases (11%) had a history of travel that was believed to have been the source of their infection. These proportions vary by municipality, and two 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.
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Case and contact follow-up
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Figure 7: Percentage of COVID-19 cases reached by Public Health within one day of being reported, Halton Region, cases reported Jul. 9-15, 2020
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Figure 8: Percentage of COVID-19 community contacts reached by Public Health within one day of being reported, Halton Region, contacts identified Jul. 9-15, 2020
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Figure 7 shows that 100% of Halton cases reported over the past seven days (Jul. 9-15) 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 99% of contacts identified over the past seven days (Jul. 9-15) 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.
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Case outcomes
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cases who have ever been hospitalized to date (four listed as currently in hospital)
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cases who are recovered/resolved
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cases who have died to date (12 of the deceased were residents or patients of an institution experiencing an outbreak)
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Institutional outbreaks
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confirmed institutional outbreaks of COVID-19 reported to Halton Region Public Health to date (none are ongoing)
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Figure 9: COVID-19 institutional outbreaks, by date outbreak was declared, Halton Region, Mar. 1-Jul. 15, 2020
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Figure 9 shows the 21 confirmed outbreaks of COVID-19 in Halton institutions reported by end of the day on July 15. 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.
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Lab testing
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Halton residents were tested for COVID-19 within the past seven days of available data (Jul. 5-11)
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Halton residents are known to have been tested for COVID-19 to date
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Figure 10: Number of people tested for COVID-19 and percentage of people tested who had positive results, by week, Mar. 1-Jul. 11, 2020, Halton
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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 (Jul. 5-11) 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 (Jul. 5-11), 0.4% of people tested for COVID-19 tested positive, although this number is subject to reporting delays.
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Comparison to Ontario
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total confirmed COVID-19 cases reported in Ontario to date
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Figure 11: Age-specific rates of COVID-19 (per 10,000 population), Halton Region and Ontario, 2020
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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 except youth aged 0-19. For example, Halton has 38.0 cases per 10,000 residents aged 80+, which is statistically significantly lower than the 88.2 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.
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Data sources
Halton case data: integrated Public Health Information System (iPHIS), extracted at 7:00 AM on July 16, 2020, to reflect data entered by the end of the day on July 15, 2020
Halton lab data: Institute for Clinical Evaluative Sciences, Number of individuals who were confirmed positive for COVID-19, COVID-19 Testing Period: 15 Jan 2020 to 11 July 2020. Received on July 13, 2020.
Ontario case counts: Public Health Ontario, Epidemiologic Summary, COVID-19 in Ontario: January 15, 2020 to July 15, 2020, posted on July 16, 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.
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Data notes
All cases of diseases of public health significance diagnosed in Ontario are entered into iPHIS by local public health units. iPHIS is the Integrated Public Health Information System. It is a dynamic disease reporting system which allows ongoing updates to data previously entered. As a result, data extracted from iPHIS represent a snapshot at the time of extraction and may differ from previous or subsequent reports as data are updated.
The data only represent cases reported to public health and recorded in iPHIS. 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.
Cases are included if their “diagnosing health unit” in iPHIS is Halton Region, which means counts include only individuals whose primary residence is in Halton Region. The case may not necessarily have been managed by Halton Region, if they were temporarily residing elsewhere during their case management period. Cases managed by Halton Region who normally live elsewhere but who were managed by Halton Region staff because they were temporarily residing in Halton during their case management period have not been included.
Cases for which the Disposition Status in iPHIS was reported as ENTERED IN ERROR, DOES NOT MEET DEFINITION, DUPLICATE-DO NOT USE, or any variation on these values have been excluded.
Cases are considered "currently active" if they are open in iPHIS.
Figures 1 and 2 distinguish between lab-confirmed and probable cases. Probable cases are defined as epi-linked cases, which means they are presumed to have COVID-19 because they have symptoms compatible with COVID-19 and have travelled to an affected area; have had close contact with a confirmed case; lived in or worked in a facility known to be experiencing an outbreak of COVID-19; or have indeterminate test results. All other figures and numbers include both confirmed and probable cases combined, except Figure 3, which uses confirmed cases only.
Figures 1 and 2 use episode date, which is a field that is intended to approximate the symptom onset date for each case. It is calculated hierarchically, using symptom onset date if available; when it is not available, specimen collection date is used; if neither symptom onset nor specimen collection date are available, the lab test date is used; and finally, if none of these other dates are available, the date the case was reported to Public Health is used.
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 iPHIS, 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 exposure and risk factor fields from iPHIS to determine whether a case travelled, was a resident/patient or staff member in an institution/congregate care setting/workplace experiencing an outbreak, 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.
Case outcomes (hospitalizations, recovered/resolved, deaths) reflect the latest available information reported to Halton Region Public Health and recorded in iPHIS by the extraction time. Cases for whom public health follow-up was discontinued and the case was closed while still hospitalized are not considered to be 'currently hospitalized'.
Cases are considered to have been reached within 24 hours if their investigation start date and case reported dates in iPHIS are no more than one day apart.
Contacts are manually tracked to determine if they were reached within one day.
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.
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 which result in the numbers being underestimates:
- 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 they were tested for. 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 suppressed;
- The location of tested individuals was based upon the test recipient’s postal code (and corresponding PHU) 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.
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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
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