OTTAWA -- An equal number of Canadians who have tested positive for COVID-19 contracted the virus within their communities and from travel, according to Canada’s Chief Public Health Officer Dr. Theresa Tam.

She said this demonstrates a "fundamental shift" in the transmission of the disease within Canada.

"Cases are almost now an equal mix between travellers who were exposed to the virus outside of Canada and their close contact, as well as cases that were exposed in the community setting in Canada," said Tam.

This shift demonstrates that an increasing number cases are being spread within the community. Deputy Chief Public Health Officer Dr. Howard Njoo explained, speaking in French, that cases coming from travellers abroad were, "at the beginning," the cause of 90 per cent of cases.

That number then continued to drop and is now at about 50 per cent.

Njoo said that the cases we’re seeing now are based on exposure to cases that happened two to three weeks ago. The increase in community transmissions in relation to travel-related transmissions underscores the need for Canadians to undertake physical distancing, he added.

Tam also provided an additional detail on these community transmissions, pointing out that many of the community-acquired cases are clustered in long-term care facilities housing seniors and people with underlying medical conditions, resulting in some recent deaths.

"That is a characteristic right now of Canada's community-acquired cases. What is the answer? Be extremely stringent about how you protect those settings," said Tam.

She also pointed out that a working-age medical professional who attended a dental conference tested positive for COVID-19. That conference resulted in another series of community transmissions, including one death.

She said understanding these kinds of transmissions is important for aligning the right solution to the problem that's being experienced.

"We've now shut down conferences and mass gatherings," said Tam.

"We're saying stay home, and maintain a two meter distance from others. So that response, to me, is there to reduce that kind of community transmission."

Tam said it's a message she plans on continuing to reiterate.

"I am your ear worm, your broken record. It's important to reinforce these recommendations…Canadians are used to doing hard things. Let’s not tire or give up too soon. We need to get this done. So let's plank that curve."