Ontario health officials say there's a new presumptive case of the novel coronavirus in Toronto.

They said a woman arrived in Canada from China on Friday and went to North York General Hospital in Toronto with an intermittent cough.

The province said the woman was tested for the new virus, known as COVID-19, and was sent home for self isolation because her illness was mild.

Officials said the woman's local tests came back positive for the virus on Sunday and the sample has been sent to the National Microbiology Lab in Winnipeg for confirmation.

The province said it's unlikely that the woman was infectious.

It said she "followed all protocols and wore a mask throughout her travels back to Toronto."

Since she landed, the woman has had "very limited" exposure to other people, the province added.

'Risk to Ontarians remains low'

Officials said the province is coordinating with local public health units to ensure that they will contact and monitor passengers who sat close to the woman on the plane.

"Because of all the proper protocols and procedures that are in place to contain this virus and exposure to others was limited, I want to assure the public that the risk to Ontarians remains low," Dr. David Williams, Ontario's chief medical officer of health, said in a news release on Sunday.

"Protecting the health and well being of individuals and families across the province remains our top priority, and we continue to vigilantly monitor for and contain any and all new cases."

Williams, Dr. Barbara Yaffe, Ontario's associate chief medical officer of health, and Dr. Eileen de Villa, Toronto's medical officer of health, will provide an update on the case at 9 a.m. on Monday at Queen's Park.

According to the province, Ontario's first three cases of the new coronavirus are all "resolved," which means each of those patients have had two consecutive negative tests at least 24 hours apart.

Dr. Eileen de Villa, Toronto's medical officer of health, along with Dr. David Williams, Ontario's chief medical officer of health, and Dr. Barbara Yaffe, Ontario's associate chief medical officer of health, will provide an update on the case at 9 a.m. on Monday at Queen's Park. (Michael Wilson/CBC)

Three people in Ontario had previously been diagnosed with COVID-19, including a married couple in Toronto and a Western University student in London, Ont., after all of them had recently returned from travelling in China.

There are six known cases of the illness in British Columbia, most recently a woman in her 30s who returned to the province last week from travel in Iran.

Provincial health officer Dr. Bonnie Henry said Thursday the woman's presumptive case was relatively mild, and a number of her close contacts were already in isolation.

"This one, clearly, is a bit unusual in that the travel to Iran is something new," Henry told a news conference at the B.C. legislature.

"Iran has recently started reporting cases and we'll be working with our national and international colleagues to better understand where she may have been exposed to this virus prior to her return to Canada."

Far more Canadians are affected by the virus outside of this country. An outbreak of COVID-19 aboard the Diamond Princess cruise ship saw 47 Canadians infected.

The cruise ship was docked in Yokohama, Japan, and placed under quarantine. People who were diagnosed with the illness are being treated at hospitals there, while those without symptoms were flown back to Ontario on Friday, where they're going through another 14 days of isolation.

