VANCOUVER -- B.C. health officials announced Friday that 114 samples have been tested in the province for coronavirus, but only one has come back positive so far.

Health Minister Adrian Dix was joined by provincial health officer Dr. Bonnie Henry for the announcement, which was made in Vancouver.

That number doesn't reflect the number of people who have been tested, however, as more samples have been tested than patients, they said. 

The province's first presumptive positive case was announced by Dix and Henry on Tuesday.

Additional testing done in Winnipeg later confirmed a positive result.

Henry and Dix said weekly updates would be given every Friday on the number of tests that have been conducted.

"Having said that, if we do have a positive, we will be notifying you immediately," Henry said.

Henry said the average incubation period of the virus is around five days and generally no more than 10, so said people who travelled to China before travel restrictions were in place could start showing symptoms around this time.

"We are at a critical phase right now," she said.

"Some very restrictive measures have been taken around the affected areas in China in particular … those measures were taken really about 10 days ago and we are now at the point where people who have travelled to B.C. and to Canada who are incubating this disease may start showing symptoms."

As a result, Henry said health officials are being "very vigilant in B.C.," adding that they have a "very low threshold for testing."

Henry said she's received many questions about why so much focus has been on coronavirus, rather than other respiratory viruses like influenza.

"This is a new virus that has jumped the species barrier into humans," she said. "We have one opportunity as a global community to push this back, and this is our opportunity now."

Dix promised updates would be given if any more positive test results come back.

"When cases are found, when there are presumed positives, we will let you know," he said. "Every week we will tell you how many people we have tested.

Dix reminded B.C. residents that it's important to stay home from work and school if they're sick.

Four cases in Canada

The first patient in B.C. is in his 40s and had recently returned to Metro Vancouver from a trip to China, which included time in Wuhan city, the epicentre of the outbreak.

He lives somewhere in the area covered by Vancouver Coastal Health, with includes Vancouver, Richmond and the North Shore.

Health officials said the man was not believed to be contagious on his flight from China to YVR and said he was exposed to only a few close contacts once he arrived back in B.C. Those contacts are also being monitored by health officials as the man remains in isolation at home.

Henry said he is "doing well" and is "stable." He is still being monitored.

Three other Canadians, including a husband and wife who live in Ontario, are the other two confirmed cases in Canada. On Friday, the man was discharged from hospital after his condition continued to improve. The woman is at home in self-isolation.

Another positive case was confirmed in London, Ont. on Friday. 

Provincial health officials in Ontario said Thursday that they are investigating 27 people for possible coronavirus infection. 

Friday's provincial health update in Vancouver comes just a day after the World Health Organization declared coronavirus a global health emergency.

"That is something that is not unexpected," Henry said. "Part of the rationale for declaring the emergency is to be able to marshal resources from around the world to support all countries in being able to contain this virus."

Additional screening and cleaning measures remain in place at YVR, where some flights to and from China have been cancelled, but health officials in B.C. have continued to say the risk of transmission remains low.