More than 80 per cent of COVID-19 cases are caused by community exposures: StatCan
TORONTO -- In a dataset released Thursday morning, Statistics Canada reported that 84 per cent of COVID-19 cases across the country are caused by community exposures.
The dataset covers preliminary information on COVID-19 cases across Canada between Jan. 15, 2020 to Feb. 28, 2021. Of the 839,926 cases recorded, 704,329 cases were transmitted by community exposures.
Jean-Paul Soucy, infectious disease epidemiologist and PhD student at the University of Toronto, says that community exposure numbers may be much higher now due to different testing patterns that were implemented between the start of the pandemic and now.
“Early on, we were primarily testing travellers and kind of denying that there was a transmission, but that was quickly corrected,” Soucy told CTVNews.ca. “Early on, you see that there’s also a very small number of cases that are identified as asymptomatic, and then that proportion grows over time.”
The Statistics Canada report goes on to show that individuals between the ages of 20-29 have the highest number of total transmitted cases and cases transmitted by community exposures. Soucy says that he predicts a similar pattern if there is a third wave.
“If we’re going into the third wave, I would expect to see a similar pattern as the second wave where we start to see things spreading in younger people and also children in schools first, and then eventually spreading this case to adults in the community.”
Breaking down locations with the highest community transmission numbers
Public Health Ontario shows in their data that most outbreaks have taken place in a workplace setting, totalling 1,472 outbreaks to date. Long-term care homes follow at 1,289 outbreaks, and school and childcare at 1,105 outbreaks.
Workplaces in Quebec also make up the highest number of outbreaks out of all recorded facilities, according to government data. There are currently 275 active outbreaks in the workplace and a cumulative total of 5,087 outbreaks in the workplace.
“A lot of these places are not necessarily well ventilated,” said Soucy. “Especially if it’s a relatively cramped setting, then you’re going to hit high concentrations of the virus building up in the air over time, and if you spend a lot of time in those spaces, that can lead to transmission especially with the variants that are more transmissible.”
Contrary to Ontario and Quebec, data provided by the Saskatchewan Health Authority in November 2020 showed that 25 per cent of community transmissions are suspected to be from recreational facilities, such as ice rinks, bingo halls, bowling alleys, and casinos.
Note: Statistics Canada has noted that numbers are based off of cases with a valid response. Cases on the file that are classified as ‘not stated’, indicates that the information was not provided by the province or territory, therefore the method of transmission has not yet been determined.