More than 430 patients in Ontario hospital intensive care beds have either tested positive for COVID-19 or are suspected to have the coronavirus, a far higher number than officials have revealed.

CBC News has obtained copies of COVID-19 reports issued daily by Critical Care Services Ontario, a branch of the Ministry of Health. The reports feature more detail than has previously been made public about the impact the virus is having on hospital ICUs.

The latest report, from Saturday, shows 92 patients in critical care wards have been confirmed positive for COVID-19, while another 342 ICU patients are considered "suspected" cases.

Patients are classified as suspected cases when they have a fever or cough, and have either travelled to an area affected by COVID-19 or have been in close contact with a confirmed or probable case of the coronavirus but their lab tests are unavailable.

This means confirmed or suspected COVID-19 cases now account for roughly one out of every four patients currently in Ontario's intensive care units — the first crucial medical resource to be overwhelmed by the spread of the virus in Italy, Spain and New York City.

On Monday, Canada's Chief Public Health Officer Dr. Theresa Tam responded to this story. Here's what she had to say:

Canada's Chief Public Health Officer Dr Theresa Tam spoke with reporters on Parliament Hill on Monday 1:28

Ontarians 'should be concerned'

"All Ontarians should be concerned about any increase in COVID-19-related hospitalizations, especially those requiring intensive care and/or ventilation," said Travis Kann, the director of communications for Health Minister Christine Elliott, in an email to CBC News on Sunday.

"That is why it's critically important that every Ontarian heed the advice provided by [chief medical health officer] Dr. David Williams and leading public health officials to stay at home and avoid contact with others," said Kann. "Lives depend on it."

Despite the hundreds of confirmed and suspected COVID-19 cases, Ontario's ICUs are not full. On average, hospital critical care wards are running at an average occupancy rate of 76 per cent, leaving some 500 beds available.

The health system began a push in mid-March to postpone non-emergency surgeries, which reduced demand for critical care beds.

Based on the recent spread of the virus in Ontario, and factoring in the physical distancing measures enforced by the province, a group of Toronto-based health scientists predict that demand for ICU beds from COVID-19 patients will peak in early-to-mid-April at more than 700 patients.

A medical worker treats patients suffering from COVID-19 in an intensive care unit in Italy. (Flavio Lo Scalzo/Reuters)

'We've had quite a week'

CBC News shared the data on confirmed and suspected cases with Dr. David Fisman, an infectious disease specialist and a professor of epidemiology at the University of Toronto.

"The most striking thing is that we've had quite a week." said Fisman in an interview Sunday. The number of confirmed cases is now five times higher than last Monday, a growth rate he describes as concerning.

"It's suggestive of exponential growth [in the spread of the virus] several weeks ago — or possibly that these nursing home outbreaks that have been happening have caused an awful lot of ICU admissions," said Fisman.

He said he hopes the physical distancing measures imposed in mid-March slow down the rate at which COVID-19 patients need critical care in Ontario hospitals.

"The things that we did to prevent transmission two weeks ago hopefully will start to have an impact this week," said Fisman.

"If we continue with a 20 or 30 or 40 per cent day-on-day increase in the number of people in the ICU, we'll be out of beds with ventilators in the province in less than two weeks."

Capacity can be expanded: province

Ontario hospitals have a total of 2,053 adult critical-care beds, according to the Ministry of Health's figures, and officials say pandemic plans would allow the system to expand its ICU capacity.

While Ontario's number of confirmed COVID-19 cases in ICU has roughly doubled every two days over the past week, the number of suspected cases has not increased as rapidly.

Still, the revelation that 342 patients in Ontario ICUs are suspected to have contracted COVID-19 calls into question Ontario's official count of positive cases — reported Sunday as 1,326, in addition to 23 deaths.

The province has faced criticism for delays in producing test results and for testing a far smaller segment of its population than either Quebec, British Columbia or Alberta.

It's unclear why so many patients in the ICUs suspected of having COVID-19 do not have definitive test results. Public Health Ontario has indicated it would prioritize testing any samples from hospitalized patients.

"Once admitted, it's our expectation that suspected cases would be tested to determine if they are positive or negative, as this information could meaningfully impact an individual's clinical care plan," said Kann.

The vast majority of patients with confirmed and suspected cases of COVID-19 are accommodated in what Ontario classes as "Level 3" beds, the highest level of critical care. Among all patients currently in Level 3 care, roughly one in three are either confirmed or suspected to have the virus.

The data shows that the daily updates from Dr. Barbara Yaffe, left, have included numbers that are two days old. (Pierre-Olivier Bernatchez/CBC)

Outdated data

The reports also reveal that provincial health officials have been announcing two-day-old data when telling the Ontario public about COVID-19 patient numbers in hospital.

On Saturday afternoon, the province's associate chief medical officer of health, Dr. Barbara Yaffe, told the televised daily media briefing there were 62 confirmed cases of COVID-19 among patients in Ontario's ICUs.

However, the reports obtained by CBC News show the province hit 62 confirmed cases on Thursday, 72 on Friday and 92 on Saturday.

Last Wednesday — the first day officials gave what they said were current hospitalization numbers — Yaffe told the news briefing there were 17 patients in ICU who had tested positive for COVID-19. The report obtained by CBC News for that day shows there were actually 43.

A health ministry official said Yaffe only receives the daily data from Critical Care Services Ontario after her 3 p.m. briefing.

Critical Care Services Ontario was created in 2006 in response to the SARS epidemic, with a mandate for "better management of critical care resources across hospitals and jurisdictions in the case of a sudden spike in demand," according to its website.

Different regions, different numbers

The data does show some regional variation in the impact of COVID-19 on critical care units.

Around 40 per cent of intensive care beds in the Waterloo Wellington and Erie St.Clair health regions are taken by patients either confirmed or suspected of having the coronavirus.

The other regions with higher-than-average ICU occupancy by COVID-19 patients are: