TORONTO -- Experts say there are a variety of factors contributing to Canada's recent surge in record breaking COVID-19 cases including Thanksgiving celebrations, fewer restrictions and increased testing capacity.

Dr. Matthew Oughton, an infectious disease expert at the Jewish General Hospital and McGill University in Montreal, told CTVNews.ca family gatherings that occurred two weeks ago are a "likely contributor to the higher numbers of cases that many provinces have been reporting" in recent days.

Quebec continues to be the epicentre of the pandemic in Canada, surpassing more than 100,000 confirmed positive cases in the province on Sunday. Ontario, the second hardest hit province, registered more than 1,000 new COVID-19 cases for the first time, setting another record for the number of infections in a single day.

Ontario's Ministry of Health says Thanksgiving may be to blame for the spike while Alberta's top doctor also cited the holiday as the source of surging coronavirus cases there.

"The leading source of exposures for active cases right now are close contacts, and many of the cases that we are seeing now are the result of spread over Thanksgiving when families gathered together," Dr. Deena Hinshaw said in her provincial update on Thursday.

"People did not mean to spread COVID, but it is a reminder where social gatherings, where social distancing and masking are not used consistently are a significant risk for spread."

Prairie numbers confirm the situation is growing more dire, with Alberta yet again breaking two records on Friday, reporting an unprecedented 432 new cases and 3,651 active cases ahead of the weekend.

Saskatchewan announced 78 new cases of COVID-19, making it the second province to report a new single-day high on Saturday, while Manitoba recorded 153 new cases and two additional deaths, the fifth consecutive day new cases have topped 100.

However, Oughton warned that the Thanksgiving holiday is not the only reason why cases are increasing across the country.

"Understanding why these transmissions are occurring in real time is important if we want to identify new risk factors and reduce numbers of new infections before we see increases in more vulnerable populations," Oughton explained in an email on Sunday.

He said the change in weather may have more Canadians spending time indoors with poorer ventilation and in closer proximity to others compared to the summer months, giving more opportunities for transmission.

In addition, Oughton said provinces may be seeing higher case numbers now than during the first wave because testing capacity has increased in many areas. For example, Quebec's goal was to conduct 14,000 tests per day during the first wave. Now, the province is recording around 25,000 tests each day.

"It is possible that there were more cases in the first wave that were never tested, and that those ‘missed’ cases were more similar to the cases we are seeing today," Oughton said.

MORE RESTRICTIONS NEEDED

Despite the Thanksgiving holiday being over, Dr. Ronald St. John, the former director-general of the Public Health Agency of Canada's Centre for Emergency Preparedness and Response, is not sure that case numbers will now begin to decrease.

He told CTV news Channel on Sunday that the steady upwards trends of infections is worrisome.

"The important thing... is to look back over a period of days to see what the trend might be, and when I say trend I mean are cases going up at a steady rate, or are they actually accelerating?" St. John said. "And it looks like it's a fairly steady trend upwards."

St. John said COVID fatigue may be a reason why cases are continuing to increase as Canadians grow tired of taking virus precautions.

"We have a problem in terms of the public health measures that we can use to try to contain this virus. They depend on people's behaviour, individually and collectively… and I think people are getting very tired and as a result, I think there are some lapses in following the precautions recommended by authorities," he explained.

St. John warned that fewer virus restrictions and a decreased compliance with those restrictions may add to the surge of infections in the coming days.

"This virus will step in wherever somebody makes an exception to the public health measures, and this virus will cause more infections, chains of infections and death increases as we've seen in these provinces," he said.

Dr. Andrew Morris, a professor in the department of medicine at the University of Toronto who studies infectious diseases, says the rising tide of cases across much of Canada appears unlikely to recede if stricter measures are not imposed.

"This is a disease that grows exponentially ... and when things ramp up quickly they come on with gangbusters. We've seen that everywhere else around the world right now, especially in Europe," Morris previously told The Canadian Press.

"As it moves to older adults, you're going to see more people proportionally with severe disease. I believe we're at a point right now where these increases are largely inevitable unless there's more substantial action to try to tamp all of this second wave down."

Morris said tighter limits on group gatherings and indoor activities may be necessary.

"It is a mindset ... When the public hears that there's still a fair amount of freedom from the government, what that also tells them is that it really isn't so bad right now," he said.

On Sunday, Canada's top physician warned that minimizing the impact of COVID-19 will only work if everyone follows public health guidelines.

Chief public health officer Dr. Theresa Tam said the number of Canadians experiencing severe illness is already on the rise amid the spike in cases, raising concerns about hospital capacity.

To ensure ICUs don't become overwhelmed, she reminded Canadians to keep physically a part.

"While I know keeping physically apart is difficult, particularly when we want to mark life's important moments like weddings and funerals, now is not the time for hosting large in-person gatherings," Tam said in a written statement.

"Right now, doing the best thing to keep our family, friends and community safer means keeping safely apart, connecting virtually, and finding safer ways to care and support each other."

She implored Canadians to continue doing their part to help limit the spread of COVID-19 by keeping social circles small, maintain physical distancing and hand hygiene, and wear face masks when appropriate.

With files from The Canadian Press