For the second time this week, Ontario has set a new record for the number of COVID-19 cases reported in a single day as the province sees more than 600 coronavirus patients in intensive care for the first time since the start of the pandemic.

Provincial health officials logged 4,456 new cases of the disease caused by the novel coronavirus today, surpassing the previous record of 4,227 set just two days ago. In January, the province recorded 4,249 cases in a 24-hour period but at the time, officials suggested that the case count was inflated that day due to a data cleaup.

The rolling seven-day average of new cases in Ontario is now 3,573, up from 2,637 last Sunday.

With 56,378 tests processed over the past day, the provincewide test positivity rate surged to 7.7 per cent, according to the Ministry of Health. That is up from 6.5 per cent last week.

Another 21 virus-related deaths were confirmed in Ontario today, bringing the total number of deaths in the province to 7,552. The average daily COVID-19 death toll in Ontario is 16 today, on par with last week's average.

COVID-19 hospitalizations have hovered at just above 1,500 for the past couple of days but data released Sunday indicates that the number of  patients infected with the virus in intensive care has now surpassed 600. The province says there are now a record 605 COVID-19 patients in the ICU at hospitals across Ontario, up from 476 one week ago.

On Friday, the province issued emergency orders that will allow hospitals to transfer patients to other hospitals without obtaining their consent during "major surge events."

The orders came one day after most Ontario hospitals were instructed to suspend all elective surgeries due to the alarming number of COVID-19 patients in the ICU.

On Saturday, critical care doctor Michael Warner called on the federal and provincial governments to begin coordinating the transfer of ICU nurses and other health-care staff from less affected provinces to Ontario.

Dr. Isaac Bogoch, an infectious diseases specialist and member of Ontario's COVID-19 vaccine task force, described the COVID-19 situation in the province as 'ugly.'

"We're in a very, very challenging position right now. Our hospitals are filling up. The ICUs are full. People are being transferred to distant locations so they can have the proper ICU care that they deserve," Bogoch told CTV News Toronto on Sunday.

He said it will, unfortunately, get worse before it gets better.

"I don't think we've crested yet. It's hasn't yet been two weeks since the Easter long weekend. It hasn't been two weeks since the stay-at-home order was enacted," Bogoch said.

Record number of new cases confirmed in multiple regions

Several public health units across the province logged a record number of new cases today, including Toronto, Peel Region, Ottawa, and Durham Region.

A staggering 1,353 new cases were confirmed in Toronto today, up from the previous record of 1,218 set two days ago.

In Peel Region, 860 new cases were confirmed on Sunday, up by nearly 100 from Friday's record of 762.

For the second day in a row, Durham Region and Ottawa set new single-day records, with 329 and 377 new cases confirmed today respectively.

Another 444 new infections were confirmed in York Region today, just shy of the previous record of 457 set on Jan. 7.

The number of active, lab-confirmed cases of COVID-19 in Ontario is now 32,763, up from 24,320 seven days ago.

The province says 94,794 doses of a COVID-19 vaccine were administered over the past 24 hours and the total doses administered in Ontario to date is now 3,139,743.

The numbers used in this story are found in the Ontario Ministry of Health's COVID-19 Daily Epidemiologic Summary. The number of cases for any city or region may differ slightly from what is reported by the province, because local units report figures at different times.