'Significant increase' in number of new COVID-19 cases among under-20s in Ontario, study finds
Guelph professor Ed McBean says results support continued closure of schools and daycares
Researchers at the University of Guelph studying the impact of the COVID-19 caseload on the medical system in Canada have found the number of new cases continue to climb among people under the age of 20 in Ontario.
Ed McBean, a professor and the lead researcher, said as of mid-May, infection curves were flattening for other age groups in the province but numbers of daily new cases for people under 20 were still rising, especially in the Toronto and Peel regions.
"It was very surprising — a significant increase. They are not the biggest caseload at this point, but they are increasing at the highest rate," McBean told CBC News on Monday. "This was very unusual, especially given that daycares and schools are closed."
McBean analyzed data from Ontario public health units alongside University of Guelph engineering professor Andrew Gadsden, PhD student Brett Snider and John Yawney, chief analytic officer with Adastra Corp., an information management and data science firm in Markham, Ont.
Under federal funding last month from the Alliance COVID-19 grant program of the Natural Sciences and Engineering Research Council, the team uses artificial intelligence models to collect and analyze data on regional coronavirus infection levels, along with demographic and behavioural information.
Key findings of the study
The study found that for people under 20:
- Outside of Toronto and Peel, there were about eight cases of COVID-19 reported each day through the first half of April. That number declined to about six per day by the end of May.
- In both Peel and Toronto, cases continued to climb. In Peel, cases rose from about two per day in mid-April to about nine by the end of May. Over the same period, Toronto cases have risen from about four per day to more than 10.
For people between the ages of 20 and 29, the study found:
- Public health units outside of Toronto and Peel recorded a rapid increase in cases through early March, reaching nearly 30 per day by mid-April. Daily cases then declined to about 20 by the end of May.
- In Toronto, cases in this age group rose more gradually, to about 20 per day by May 1. Cases levelled off slightly to about 18 by the end of May. Peel region saw an even more gradual increase since March, as numbers of daily cases reached more than 20 and continued to rise at the end of May.
McBean hopes to analyze similar data from other provinces.
He said he doesn't know why the under-20 results differ, although he suspects frustration over lockdown measures is rising among children and teens as well as their parents.
Schools remain closed
While schools have been cancelled for the rest of this spring, daycare centres face more pressure to reopen, particularly as parents look to return to work.
"All of the modelling we do says, 'Gee, that's going to be a problem,' because while the very young don't typically get catastrophic impacts [from COVID-19], they have the ability to bring it into the environment of the home, where children of that age are then able to pass it on to the older generations … so that's the fear," McBean said.
"The biggest problem going forward is: how are daycare and summer day camps going to function ... because it's all to do with contact between individuals. That's the key and this is such an incredibly transmissible virus.
"Our suggestion is proceed very carefully and focus on the high-density areas and try to get a better understanding of how daycares might operate. They're chaos … everybody shares toys and everything else. There's only so much disinfection that you can actually create," McBean said.
Quebec saw an increase in cases after some students returned to school on May 11.
Between May 11 and May 31, 78 cases were confirmed among students and staff across multiple schools in Quebec.
Back to where it all began
Waterloo Region Public Health's acting medical officer of health, Dr. Hsiu-Li Wang, said her office will be taking a closer look at the trends now that there has been expanded testing and the economy has started to reopen.
"It is likely to look different because before, our numbers were very much influenced by what was happening in the long-term care homes and retirement homes," Wang said.
Calls to continue physical distancing
Wang is urging people not to let their guard down when it comes to COVID-19.
"We are always worried about people sort of feeling that, 'OK, it's safe now and I don't really have to follow the recommendations,'" she said.
"Continue to practise physical distancing, stay at home if you're sick. I think people have to remember that this virus has not gone away, that it's still circulating in our community, we still have cases and we are still at risk of very quickly having a resurgence of cases if we're not careful."