How many outbreaks are happening at work?

Citing recent stat of 5 per cent, IWH says it’s difficult to get an accurate reading and number is likely low

How many outbreaks are happening at work?
Given the way workplace outbreak data is collected, the number of cases attributed to workplace outbreaks are likely underestimated, says one group.

Cases of COVID-19 attributed to workplace outbreaks represented just over five per cent of cases among workers in Ontario in November and December, according to a report.

However, this does not include outbreaks in health care, education or congregate living settings such as jails and given the limitations of the data, that number is likely low, says the Institute for Work & Health (IHW).

Throughout 2020, only 5.3 per cent (7,955 cases) of the total 149,189 reported COVID-19 cases among working-age adults can be linked to the workplace. This is based on a summary file of all confirmed positive cases of COVID-19 in Ontario as of Dec. 27, 2020, and a specific outbreak datafile which reports the count of the number of COVID-19 cases due to outbreaks in the province, says the institute.

Ontario recently began an inspection blitz of workplaces to ensure that workers and patrons are following health and safety measure amid the pandemic.

The number of reported COVID-19 cases related to the workplace peaked in June, making up 22.2 per cent (946 cases) of the 5,413 cases reported that month. The workplace was also linked to 14.3 per cent (442 cases) of the 3,875 cases reported in July, and 11.3 per cent (850) of the 10,192 cases reported in May.

The workplace was also tagged as responsible for 5.3 per cent of cases reported for both November and December, and the number was down for the rest of the months.

In a September 2020 report, IWH noted that 20 per cent of COVID-19 infections among working-age adults in Ontario can be attributed to workplace transmission.

These calculations may not be accurate, says IWH. For one, cases that are put under workplace outbreaks do not include those reported in hospitals, long-term care and retirement homes, group homes, correctional institutions and schools.

“Given the way workplace outbreak data is currently collected, the number of cases attributed to workplace outbreaks are likely underestimated,” say IWH scientific co-director and senior scientist Peter Smith and IWH president and senior scientist Cameron Mustard in a briefing.

“This would be the case where work colleagues live together, commute to the workplace together and/or socialize outside of the workplace together. In these situations, the attribution of the exact location of transmission will be complicated and, given this uncertainty, these cases will not likely be classified as workplace outbreaks.”

Essential service sectors represent about 40 per cent of the Ontario labour force, and each month, three million Ontario workers in essential services 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, they say.

British Columbia recently started boosting enforcement of COVID-19 workplace safety.

Other exclusions
Also, there are two other types of COVID-19 cases excluded from the workplace outbreaks category: subsequent cases that result from the initial workplace outbreak case, and cases that might be transferred through a worker to a client/customer of that business – including situations in healthcare or educational settings where a worker transmits COVID-19 to a patient or student in the workplace.

“As has been the case throughout the COVID-19 pandemic, close social contact – not related to an outbreak – remains the most common source of COVID-19 transmission and underscores the need for effective physical distancing procedures in both workplace and non-workplace settings. Understanding the proportion of these close contact transmissions that occur in workplace settings (e.g. worker to client, client to client, or client to worker) remains an important information gap,” say the researchers.

“Given the strain placed on contact tracing by the large number of COVID-19 cases in the second wave, it is likely that a proportion of workplace outbreaks are not being identified.”

Canadian HR Reporter previously spoke with a lawyer about legal considerations when it comes to screening employees for the virus.

Another important current information gap is the rate of work-related COVID-19 transmission (e.g. per hour worked or exposed) generally in the working population and across industries, especially with many workers doing their job from home.

“Having a better estimate of the number of hours that Ontario workers spend in workplace settings would enable more useful comparisons between workplace outbreak numbers and outbreaks in other settings (e.g. recreational settings), which cannot be meaningfully done at present, say Smith and Mustard.

Workplace safety measures can also make a big difference when it comes to workers’ mental health, found a recent study.

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