Ontario health officials reported 100 new cases of COVID-19 in the province on Wednesday and four new deaths, taking the tally of cases including deaths and recoveries to 688.

It's the highest daily increase in active cases since the outbreak reached the province in late January.

Ontario reported 85 new infections on Tuesday.

The new tally includes Ontario’s ninth death, confirmed to have occurred late Tuesday at a hospital in Niagara. An individual in their 80s who was a resident of Ina Grafton Gage Village died 11 days after testing positive for COVID-19.

Officials said the person had close contact with a family member who recently travelled to Europe.

On Wednesday afternoon, Ontario reported four more fatalities, bringing the death toll to 13.

Toronto's medical officer of health Dr. Eileen de Villa said there are three more COVID-19 deaths in the city -- an elderly man with pre-existing condition who was tested at North York General Hospital and two residents of Seven Oaks long-term care in Scarborough.

Ottawa reported their first COVID-19 death on Wednesday evening. Ottawa public health said a man in his 90s with no travel history died in hospital.

Ontario now has 671 active novel coronavirus cases, eight patients who have made full, clinically-confirmed recoveries and thirteen deaths.

Public health units in Durham and Hamilton confirmed Ontario’s seventh and eighth deaths from the virus earlier on Tuesday.

Health officials said that of the 100 new cases, five patients required hospitalization.

They include a man and woman in their 50s from the Porcupine (northeastern Ontario) health unit, a woman in her 80s in London Middlesex, a woman in her 70s from Halton Region who recently returned from Spain and a woman in her 20s in Peel Region.

Thirty of the cases were tied to recent travel to locations including the United States, the Dominican Republic, Spain, Britain, Egypt, Peru, Mexico, the Philippines, the Bahamas and France.

Twenty-two cases were attributed to close contact with a previously confirmed case, while the cause of the remaining 48 was listed as under investigation.

The increased case growth comes as Canada’s chief medical officer said Tuesday that nearly half of the country’s reported COVID-19 infections in recent days were caused by community transmission.

Of the 69 patients where the province disclosed at least some case particulars, 21 were from Toronto, 13 were from Peel, 5 were from Kingston, Frontenac, Lennox and Addington Health Unit, 5 were from York Region, four were from Halton, another four were from Hamilton and three were from Porcupine Health Unit in northeastern Ontario.

Two of the five patients in Kingston, Frontenac, Lennox and Addington are a boy and girl under the age of 18.

Two other cases were detected in Peterborough, along with one case in Durham Region, one in Niagara, two in Windsor-Essex, one in Timiskaming, one in Haliburton-Kawartha, two in Hastings – Prince Edward, one in Simcoe-Muskoka and one in Wellington-Dufferin-Guelph.

Officials said 40 people are currently in hospital. Of those, 17 are in the intensive care unit. Fifteen are on ventilators.

Wednesday morning’s disclosure indicates provincial and hospital labs were able to get through 2,763 tests since Tuesday, but the backlog in testing grew slightly to 10,489 specimens due to a major jump in approvals for testing.

Both Ontario’s chief medical officer of health, Dr. David Williams and Health Minister Christine Elliott have said the province is working to build capacity to complete 5,000 tests per day, but global shortages of items critical to testing such as specialized nasal swabs and re-agent are complicating that effort.

Speaking to reporters on Wednesday afternoon, Associate Chief Medical Officer of Health Dr. Barbara Yaffe said there is backlog because they are prioritizing healthcare workers, long-term care patients, homeless people, and people in First Nation communities.

The backlog has also affected the number of cases resolved. In order for a case to be classified as resolved, a person needs to have tested negative for the virus twice that are least 24 hours apart.

Yaffe said those tests had not been prioritized.

As a result, she said they have come up with different criteria to determine if a case has been resolved.

The following criteria include: not hospitalized, does not involve healthcare workers, they have recovered, and it's been fourteen days since they became ill.

"Our numbers of resolved are expected to go up," said Yaffe.

Williams said they are looking into how the federal government is going to enforce its mandatory quarantine measures announced Wednesday.

"We'd be able to contact them to ensure tare they able to do their isolation, and we want them to do that.

"If there are any problems that they need to address, we can help them assess that so they can maintain that isolation in their home setting as quickly as possible, and that means get back to their home location and set that up," Williams said.

He said they are concerned about the situation in the U.S. and their rising COVID-19 cases.

Officials said the majority of travel-related cases are from the U.S.