In the second wave of the pandemic in Ontario, outbreaks in essential service workplaces (excluding health-care, congregate living and educational settings) have contributed just over five per cent of all cases among working-age adults in Ontario.
Conversely, since October, close contact has been the source of acquisition in 40 per cent of all cases among the working-age population. As well, for a substantial number of COVID-19 cases in this population, we do not have enough information to know how the case was acquired.
This is according to a new Institute for Work & Health (IWH) Issue Briefing that’s based on publicly available data from the Ontario Data Catalogue, up to January 10, 2021.
That less than six per cent of new COVID-19 infections among working-age adults in the second wave of the pandemic can be attributed to workplace outbreaks (not including outbreaks in health-care, congregate living and educational settings) suggests the importance of the often-substantial adjustments to work practices implemented by employers.
Since the beginning of the pandemic, more than 7,900 cases have been attributed to workplace outbreaks among workers in essential services, who make up about 40 per cent of the Ontario labour force. Each month, three million Ontario workers in these sectors have worked more than 400 million hours in proximity to co-workers and, in some cases, providing services to clients, customers and other members of the public.
To analyze the role of workplaces in COVID-19 transmission, we drew on the number of COVID-19 cases due to outbreaks. Workplace outbreaks are defined as situations in which two or more COVID-19 cases occur within a 14-day period in the same workplace, with one or more cases having been reasonably acquired in the workplace (e.g. no obvious source of infection outside the workplace and a known exposure source in the workplace).
The outbreak datafile includes six categories of outbreak-related cases: health-care settings (which include hospitals, long-term care homes and retirement homes), congregate living settings (which include correctional facilities, shelters and group homes), education settings, other workplace settings, recreation settings and unknown settings.
Given the way workplace outbreak data is currently collected, the number of cases attributed to workplace outbreaks are likely underestimated. This would be the case where work colleagues live together, commute to the workplace together and/or socialize outside of the workplace together.
Workers infected in health-care, congregate living and education settings are not included in the workplace outbreak numbers examined in our analysis. That’s because outbreak-related case numbers for these settings are not routinely broken down by cases among employees versus patients, clients or students.
According to other data sources that separate out employee cases, 28 per cent of cases due to outbreaks in long-term care facilities have been among staff members. In educational settings, 15 per cent of all cases—not just those related to outbreaks—were reported among staff.
In the months ahead, diligence in workplace infection control practices will be crucially important to protect the health of essential service workers.
—Dr. Peter Smith, Scientific Co-Director and Senior Scientist, and Dr. Cameron Mustard, President and Senior Scientist, Institute for Work & Health