As COVID-19 cases threaten to overwhelm hospitals in several parts of Canada, one doctor is warning that hospitalizations are reaching record highs in some provinces, which could further reduce general hospital care for the foreseeable future.

Dr. Tasleem Nimjee, the physician lead for the COVID-19 emergency response at Humber River Hospital in Toronto, told CTV's Your Morning on Tuesday that her hospital is "very stretched" already.

"The number of patients that we're admitting every day is very, very high. We have many days where we're admitting an average of 20 patients a day and you can imagine at some point that just becomes no longer feasible," Nimjee said.

She explained that the "flow" of a hospital's ability to function and provide effective and efficient aid can become "very tight" if there's a sudden surge of patients that require care.

Nimjee says hospitals in Ontario are filling up at an alarming rate. According to provincial data, there were 480 people in hospital due to COVID-19 two weeks ago. As of Monday, there are nearly 2,500 patients in hospitals.

Nimjee said hospitals have used "every lever that we have in the system to try to create capacity" amid this increase in hospital admissions to no avail. What would help now, she says, is an "injection or boost" of health-care workers, such as military aid.

However, federal officials have said that might not be possible.

Facing this record-setting rise in cases, Infrastructure and Communities Minister Dominic LeBlanc told reporters Friday during a press briefing that the federal government anticipates increasing requests from provinces and territories in the coming weeks and will do everything they can to respond, but ultimately health care is provincial jurisdiction.

"We as a government have to efficiently use the federal resources we can bring to bear to fill the gaps that provinces and territories are identifying," LeBlanc said, noting that the new variant is "having a major impact on the day-to-day lives of Canadians."

LeBlanc said that the federal government will be speaking with all of Canada's premiers this week to talk next steps and co-ordinate the expected onslaught of requests for support.

"It shouldn't surprise anybody that it's not a limitless number of federal health-care resources that we can bring to bear," he said.

Because of this, Nimjee said Canadians should anticipate further reductions in hospital services.

"You've seen a decrease in surgical volumes as a result, unfortunately, and I know that that impacts patients in a very real way. But I expect that actually to increase because I just don't see how the system will cope otherwise," she said.

"You're going to see further sort of cutbacks and further I think decreases to general access to care while we shift all of our resources to manage this surge."

Nimjee acknowledged that this strain is being felt across the health-care system, affecting paramedics are other first responders, not just those working in hospitals.

In previous waves of the COVID-19 pandemic, Nimjee noted that provinces would borrow health-care workers from regions that weren't hit as hard. However, she says that will be "much more difficult this time around" with Omicron's impact being felt across the country.

She added that if multiple provinces request military aid, there simply won't be enough members to help every hospital. Nimjee said this can result in an erosion of care in hospitals.

"We're doing things like asking family members to support us as essential care workers when we're short nurses," she said.

The Canadian Medical Association (CMA) issued a statement Tuesday urging federal, provincial and territorial governments to work together to minimize the impact of the current wave of COVID-19 amid concerns that the surge in Omicron infections may leave the health system unable to recover.

"We know Canadians are tired and frustrated. Physicians, nurses, respiratory therapists, pharmacists, laboratory technologists and other health care providers are beyond exhausted right now. And we need all hands-on deck to stabilize our health system to care for COVID patients and all others requiring care," said CMA President Dr. Katharine Smart in the statement.

WHO IS BEING HOSPITALIZED?

The rise in cases comes amid the spread of the new Omicron variant. While believed to be more transmissible and able to evade some vaccine protection compared to the previous Delta variant, evidence has emerged that it may result in less severe illness and reduce the chance of being hospitalized.

However, Nimjee says Omicron still poses great risk to the unvaccinated.

"When you start to look at ICU volumes, and certainly when you look at those that have severe outcomes, or complications, those are happening disproportionate in the unvaccinated," she said.

But not all hospital admissions are directly related to COVID-19. Nimjee explained that someone coming in for a scan or a routine procedure may test positive for the virus and be asymptomatic. While someone in that situation is unlikely to be admitted for long, Nimjee said it still puts a strain on the hospital.

"If somebody is coming into hospital and it's found that they have COVID, usually their hospitals stay is lengthened by the fact that they have COVID," she said.

In addition, Nimjee said she's also seeing more Canadians admitted with only one or two doses of a COVID-19 vaccine. While their symptoms are less severe than those of the unvaccinated, Nimjee said they may still need hospital care for a few days.

"The challenge here is that… people that have just two vaccines, for example, not necessarily having a booster, are still being admitted. And maybe they don't have long stay admissions, but they are still being admitted. So less severe outcomes, but still an increase in… hospital capacity," Nimjee said.

Chief Public Health Officer Dr. Theresa Tam said Friday that severe illnesses due to the Omicron variant are not rising at the same "explosive rate" as case numbers. However, she noted that hospitalization rates are rising because of the "sudden acceleration of Omicron and enormous volume of cases."

While the surge in cases has testing capacity stretched, resulting in underestimated case numbers, Tam said public health agencies are using other indicators like laboratory test-positivity rates to monitor the overall disease activity across the country and its impact on hospitals.

"We can all help by reducing our contacts to get us through this difficult time that much faster," Tam said. "This might feel like a double marathon that we didn't sign up for, but despite feeling tired, we should have a sense of achievement for the ground we've covered so far."

With files from CTVNews.ca's Rachel Aiello