Health-care workers make up roughly one in every 10 of the known COVID-19 cases in Ontario, totalling 229 lab-confirmed cases to date, CBC News has learned.

The finding is ringing alarms as hospitals across Canada are bracing for an expected surge in patients with the potentially deadly respiratory illness — which comes amid ongoing concerns over potential shortages of personal protective equipment for front-line health-care workers.

"We need all hands on deck," warned Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital. "And we need all those health-care workers working, because we're expecting to see a greater number of patients in the hospitals and clinics in the next few weeks ahead."

The Ministry of Health provided the data on Wednesday in response to an inquiry from CBC News.

It reveals 9.6 per cent of the province's 2,392 confirmed COVID-19 cases involve physicians, nurses, paramedics, personal support workers, long-term care home staff and members of other health-care professions.

Provincial officials did not provide a breakdown of Ontario's confirmed cases involving health-care workers by specific roles, transmission source or region.

High number in Toronto, Ottawa, Waterloo, York

CBC News reached out to each of the province's 34 public health units for more context on local confirmed health-care worker cases.

Multiple health units from less-populated regions declined to provide numbers, including Chatham-Kent Public Health, which cited potential privacy concerns given the small number of total cases reported there to date.

The public health unit from Peel region said roughly 30 of the area's 362 confirmed COVID-19 cases work in health-care settings or front-line care. Waterloo region said 28 of the area's 117 confirmed cases are health-care workers. In Ottawa, there are 28 health-care workers and first responders out of 194 cases, while in York region, the count is 26 out of 325 cases. In Peterborough, it is 12 out of 28.

Each unit uses different metrics to tally positive cases in the health-care profession, with some focusing only on workers involved directly in patient care, and few offering precise breakdowns by role.

'We need all hands on deck,' warns Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital. (Maggie MacPherson/CBC)

As for Toronto, the latest numbers show that out of at least 818 total known cases to date, at least 31 front-line workers have contracted the virus so far — including 12 physicians, 13 nurses and six other health-care workers. Earlier data suggested a higher count, but public health officials are now reporting only patient care roles.

"The majority of these cases of COVID-19 are travel-related," noted Toronto Public Health spokesperson Lenore Bromley.

Bogoch said the fact that travel is the primary transmission source, rather than a clinical setting, gives some "peace of mind." But he cautioned that some cases are already health-care-related, a situation that could worsen if workers aren't properly protected.

"There still is some rationing of personal protective equipment and we have to take care of that issue right now," he said.

Concerns over equipment rationing, shortages

As CBC News recently reported, some Toronto hospitals are rationing surgical masks and even urging nurses and other front-line staff to use just one mask for an entire shift, according to internal memos.

Health-care workers and advocates have raised concerns over looming shortages of the full range of protective gear.

"My worst fear is that [the province] will continue to be fairly inactive on the file. It didn't order enough equipment," said Michael Hurley, president of the Ontario Council of Hospital Unions with CUPE, which represents roughly 90,000 workers across the health-care system, including registered practical nurses, paramedics and personal support workers.

Many hospitals are already "running low," Ontario Hospital Association President and CEO Anthony Dale warned in a Wednesday news release, which called on both the federal and provincial government to outline timelines when fresh supplies will be delivered.

Members of the public wait to be tested at a COVID-19 assessment centre located at Toronto's Michael Garron Hospital. (Evan Mitsui/CBC)

In a statement, Ontario Ministry of Health spokesperson Travis Kann said the province is investing $75 million to supply personal protective equipment and critical medical supplies to front-line staff.

The province expects to deliver supplies in the days and weeks ahead, including 12 million more sets of gloves, one million more N95 respirators and nearly six million more surgical masks, which would be on top of the millions of masks and thousands of ventilators the federal government is also ordering.

"The health of all Ontarians, including and especially the brave heroes working on the front lines to stop the spread of COVID-19, is our top priority," Kann said.

Long-term care a 'nightmare environment'

Hurley worries it's not coming fast enough.

"We're already seeing in hospitals and long-term care people who are acquiring this illness at work," he said. "We're going to see those numbers go up significantly."

Long-term care in particular is a "nightmare environment" in which outbreaks are already happening, Hurley stressed.

Clinicians and advocates have raised red flags about potential shortages of personal protective equipment at Ontario hospitals. (Evan Mitsui/CBC)

In recent days, eight residents of the Seven Oaks Long Term Care Home in Scarborough have died as result of COVID-19 amid an outbreak at the facility, according to Toronto Public Health.

Province-wide, more than 40 deaths of residents in nursing and retirement homes have been linked to the illness so far, and at least 41 facilities for seniors in the province are currently experiencing outbreaks — defined as one lab-confirmed positive test involving a resident or staff member.

The latest numbers show case counts keep rising more broadly, alongside crucial metrics revealing a growing number of patients hospitalized in Ontario's intensive-care units.

The province confirmed 426 new cases on Wednesday, marking a nearly 22 per cent increase in the total number of infections and the largest single-day jump since the outbreak began — bringing the total of known cases to 2,392.

A CBC News investigation also found there are now at least 430 patients in intensive-care unit beds who either have tested positive or are suspected of having COVID-19.

Given the rising number of patients needing high levels of medical care, the number of health-care workers already ill is "upsetting," Bogoch said.

"We can't afford them getting sick."