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Public Health Sudbury & Districts medical officer Dr Penny Sutcliffe confirmed an attendee to the conference, which saw about 23,000 people gathered under the same roof, had tested virus-positive upon returning home.

"I am confirming that based on our investigations so far, the individual was not infectious while attending the PDAC 2020 conference March 2 and 3 in Toronto," said Sutcliffe.

"Our working hypothesis at this time is that this individual was exposed to Covid-19 while at the conference and therefore we are advising those who attended the conference to monitor for symptoms for 14 days since leaving this event."

The male in his 50s presented himself to the emergency department at Health Sciences North on March 7, but has been discharged home where he remains in self-isolation.

"Our focus is on breaking the chain of transmission to limit the spread of infection and as a precautionary measure, we are asking those who attended PDAC 2020 to monitor for symptoms for 14 days," said Sutcliffe.

The Prospectors and Developers Association of Canada said in a statement to Mining Journal Wednesday it was supporting a detailed investigation conducted by Sudbury and Toronto public health agencies of the man's activities while attending the PDAC 2020 convention.

More than 23,000 people from around the world attended the conference including prime minister Justin Trudeau and of natural resources minister, Seamus O'Regan.

O'Regan said Wednesday night on social media he was isolating himself until he got the results of a Covid-19 test back.

"I've had a persistent head cold for a few days so, as a precaution, I saw a doctor. They recommended a test for Covid-19. I'm not aware of contacting anyone infected, but was told to remain in self-isolation until we get the results. Feel fine. But I'll work from home," he tweeted.

The various tiers of Canadian health ministries have also advised travellers to monitor their health for fever, cough, and difficulty breathing for 14 days after arriving back in Canada. If symptoms develop within 14 days, returning travellers are directed to self-isolate as quickly as possible and immediately call their health care professionals or public health to arrange to be tested.