Health experts are warning that the current rise in COVID-19 cases across the country will likely increase through January and February due to gatherings during the Christmas holidays and New Year's.

Infectious disease expert Dr. Sumon Chakrabarti explained to CTV News Channel on Friday that current cases numbers measure those that would have become infected prior to the holiday season. Given the novel coronavirus’ one-to-14-day incubation period, he says, Canadians will start to see the impact of gathering over Christmas this week.

"We do know that there was a significant amount of transmission that occurred around Christmas time, and unfortunately with New Year's being just about a week [after], you're at your most infectious. And at that point you can get almost this -- for lack of a better phrase -- double whammy, and I do think January unfortunately is going to be a bit of a bumpy ride for us in health care," Chakrabarti said.

Despite public health measures being in place, Chakrabarti said he is concerned about the Canadians who chose not to follow guidelines and gathered with friends and family during the holidays.

"I'm more worried about the likely indoor gatherings that were happening all over invisibly, but happening all over the country. I suspect it's going to lead to a significant amount of cases in the coming weeks," he said.

Canada passed 600,000 total COVID-19 cases since the start of the pandemic on Sunday, as provinces continued to tally the data they didn't release over New Year's.

More than 5,800 new COVID-19 infections and nearly 100 deaths were logged in Ontario between Dec. 31 and Jan. 1 as the province smashed its previous record for most cases reported in a single day.

On Sunday, Quebec reported 7,613 new cases over the past three days, including a record-breaking 2,869 in the past 24 hours. Provinces in the Prairies have also reported a spike in cases over the past week.

Infectious disease expert Dr. Isaac Bogoch told CTV News Channel that current case numbers are "really, really ugly" and are expected to rise despite lockdowns being issued in some regions after the holidays.

"We're already dealing with the healthcare system that is stretched beyond capacity in many parts of Ontario and certainly in many parts of Canada. So I think, unfortunately, things are going to get worse before they get better," Bogoch said in an interview on Saturday.

However, Bogoch pointed out that certain socio-economic inequalities prevent some Canadians from adhering to virus restrictions despite them being in place.

"We still know that there's essential workers going to essential jobs, we know some people are going to work sick because they don't have the capacity to stay at home or paid sick leave. We know that there's still a lot of sadly inequities that are driving these numbers and quite frankly, those haven't been fully addressed," Bogoch said.

"It comes to no surprise that these numbers will continue to rise when you factor that with probably some holiday gatherings as well," he added.

ARE LOCKDOWN MEASURES WORKING?

Dr. Ronald St. John, former director general for the Public Health Agency of Canada, told CTV News Channel on Sunday that lockdown measures remain Canada's best defence against COVID-19 transmission.

"Lockdowns and restrictions are the tools that we have at present time until the vaccine can reach more people," St. John explained. "Now is the time to continue to follow the lockdown rules as necessary. It's not the time to get COVID and spread it to your parents or your grandparents or your children or anybody else."

While vaccines have begun being rolled out, St. John said Canadians need to continue to keep their social contacts low, adhere to physical distancing, and wear face coverings when adequate distance cannot be achieved.

Despite some experts anticipating an increase in cases due to the holidays, Dr. Zain Chagla, an infectious disease physician at St. Joseph's hospital in Hamilton, Ont., is hopeful that lockdown measures will continue to work.

Chagla, who is also an associate professor at McMaster University, told CTV News Channel on Saturday that he believe the "vast majority of people did comply" with public measures over the holidays.

"Yes, we are seeing people that didn't, but in public health we worry about what the bulk of the population does, not necessarily what a small percentage does and hopefully that large percentage does cover things off," he said.

Chagla added that "only time will tell" if lockdown measures can keep transmission low.

"We've see promising signs from elsewhere in the country that have had to institute these measures and I hopefully think in the next week we will start seeing the rewards of this start showing up," he said.

Given that many stores and restaurants remain closed, Chagla explained it is likely that COVID-19 cases caused from gathering over the holidays won't lead to as widespread community transmission as they would have if those businesses were open.

"Even if those transmission events have happened in some of those gatherings in private residences, there's not a lot of places to send it afterwards in the sense that people's contacts are limited," he said.

LEADING BY EXAMPLE

While lockdowns are in place in some parts of the country, Dr. Amy Tan, a family and palliative care physician in Calgary, said those measures will only decrease infections if Canadians follow them.

"We know that these restrictions do work. The adherence of them though is what is needed for them to work. We can't just institute the rules, we actually need the public to abide by them," Tan told CTV News Channel on Saturday.

Tan added that there also needs to be stronger role modelling of public health measures from Canada’s politicians.

"We need our politicians to actually be following the same rules, to be role modeling this type of behaviour. These are not normal times, we have the end and hope in sight, but we need to redouble our efforts," she said.

Tan says that Canadian politicians who have recently travelled abroad amid the worsening COVID-19 pandemic are sending "the wrong message."

Current federal public guidance says to avoid all non-essential travel outside of Canada, something Prime Minister Justin Trudeau and health authorities have repeatedly reiterated in public briefings. However, multiple MPs and MLAs have found themselves in hot water after being caught vacationing.

"I think it says that politicians are above the rules, and they are going to espouse the rules, but actually not walk the walk and that's not what we need right now. We need everybody, including and most definitely the leadership, to be walking the walk along with the public," Tan said.

"We need our leaders to really be role modeling this up front and centre."