TORONTO -- The number of COVID-19 cases in Ontario has surpassed 500.

On Monday morning, health officials in the province confirmed that 78 more people had tested positive for the novel coronavirus.

More than 8,000 people are currently under investigation for the virus and nearly 20,000 people in the province have tested negative, officials stated as the new patients were confirmed just before 11 a.m.

The provincial total now sits at 503 cases in total.

The new patients include 15 in Toronto, eight in York Region, six in Peel Region, three in Hamilton, three in Durham Region, and two in Halton Region.

As well, three new cases have been confirmed in Ottawa, and there is one more case confirmed in Hastings Prince Edward, Sudbury, Simcoe Muskoka, Wellington Dufferin Guelph, Haliburton Kawartha Pineridge, Waterloo, Eastern Ontario and the Kingston area.

The locations of the additional cases are all listed as “pending.”

Fourteen of the new cases are travel-related, 16 are linked to a close contact of a previously confirmed case of the virus and the rest all have their means of transmission listed as “pending.”

Six of the new patients remain in hospital receiving medical treatment and five others remain in an institution, officials stated. The Ministry of Health said they typically define an institution as a long-term care home or a nursing home, but added that it can also be used to describe "group homes, mental health facilities and correctional facilities.”

The other cases are either in self-isolation at home or their location is listed as “pending.”

On Monday, the province also confirmed a COVID-19-related death in Ontario that was announced by health officials in Haliburton Kawartha Pineridge earlier in the day.

The man, who was in his 80s, died at a Lindsay, Ont. hospital on Sunday afternoon after experiencing a high fever and other influenza-like symptoms. Officials in the region said he had no recent travel history and is believed to have contracted the virus through community transmission. His means of transmission on the province’s website is listed as “pending.”

His death was the sixth COVID-19-related fatality in the province. The other deceased patients include a 77-year-old Barrie, Ont. man, a 51-year-old Milton, Ont. man, a man in his 70s in Toronto, a woman in her 70s in York Region, and a man in his 70s in Barrie, Ont.

On Monday afternoon, Ontario Health Minister Christine Elliott said there are a total of 23 COVID-19 patients currently in hospital.

Eight people in Ontario previously infected with the virus have since recovered.

26 healthcare workers test positive for COVID-19

Speaking with reporters on Monday afternoon, Ontario's Associate Chief Medical Officer of Health Dr. Barbara Yaffe said that 26 healthcare workers have tested positive for the virus.

"The fact that they are healthcare workers makes them a priority group for testing," Yaffe said. "We do not know specifically if they acquired the infection in the community, with travel or at work."

Criteria for COVID-19 testing in the Greater Toronto Area has changed to prioritize people who are exposed to large groups of people, such as those who work in the healthcare sector or those who reside in homeless shelters, retirement homes or prisons.

Health officials said the shift was due to evidence of community spread within the GTA.

Yaffe told reporters that 17 per cent of Ontario's COVID-19 patients had no history of travel and were not close contacts of another case.

"I think it's fair to say that yes in some small percentage of cases...there may be some local transmission of COVID-19," she said.

"The number of positives is going up every day. It's going up more and more. We know that we're not able to test everybody yet...when we're looking at the number of cases, it's not the complete number of cases."

Of the 503 cases in the province, 71.2 per cent had travelled within 14 days of becoming ill. Twelve per cent were a close contact of a confirmed case, Yaffe confirmed.

Symptoms of the virus, which can include fever, cough and shortness of breath, are similar to other respiratory infections.

There are no specific treatments for the virus and there is no vaccine that protects against it.