The first person confirmed to have become ill from the coronavirus in B.C. has fully recovered and is no longer required to stay in isolation, according to provincial health officer Dr. Bonnie Henry.

Three other people in B.C. with COVID-19 are no longer showing symptoms, she said Wednesday. "That's very good news."

On Friday, Henry announced the province's fifth presumed case of coronavirus after a woman in her 30s returned from Shanghai, China, through Vancouver's airport before travelling by car to her home in the Interior.

Henry said that woman still has symptoms and is in stable condition in isolation at her home. She said the woman was wearing a mask while travelling, and they have identified a small number of people who had close contact with her.

Dr. Bonnie Henry assesses the health of the first four people in B.C. diagnosed with coronavirus:

B.C.'s top doctor says the conditions of the first four people in B.C. diagnosed with coronavirus have improved. 0:32

Henry said health authorities are following up all leads between those who have been confirmed and anyone they might have had contact with.

"This is the work that we do in public health in our communities," said Henry.

500 tested in B.C.

A new report by China's centre for disease control has provided more information on why some people get over the new virus as if it were a cold and others become ill or die, Henry said.

Most of the first 72,000 cases were older people with chronic conditions such as diabetes and heart disease, and 14 per cent of those who died from the disease were over age 80, she said.

"There were very few cases in people under the age of 19, less than 1,000 of the 72,000, and there were no serious illnesses and no deaths among young people," similar to infection from other cornaviruses, Henry said.

The most patients were between the age 30 and 59 and about 80 per cent of them had mild cases, Henry said.

"That means the virus could be transmitted quite easily, from people with mild illness, and that's something we're also learning.''

Eight cases of COVID-19 have been diagnosed in Canada. Most of them were people who had come from Hubei province in China, considered the epicentre for the illness.

Over 500 people have been tested for the virus in B.C., and many tested positive for influenza, Henry said. She added that hand washing is the most effective way to prevent any of the viruses from spreading.

This undated electron microscope image made available by the U.S. National Institutes of Health in February 2020 shows the coronavirus known as 2019-nCoV, which causes COVID-19. (NIAID-RML via AP)

Diamond Princess cruise ship

Cruise passengers, including 256 Canadians, who have been quarantined on a Diamond Princess cruise ship for the last two weeks, began to disembark in Japan Wednesday.

Global Affairs says 43 Canadians were among the 621 passengers aboard who have tested positive for coronavirus.

Henry said B.C. officials have been monitoring the situation closely.

A bus carrying passengers leave the port after passengers disembarked from the quarantined Diamond Princess cruise ship Wednesday in Yokohama, near Tokyo. (Jae C. Hong/The Associated Press)

The federal government has chartered a plane to bring home Canadians who have not tested positive.

She said the plane would fly directly to Trenton, Ont., and then Cornwall, where the passengers would be required to go through another 14-day quarantine period.

Last week, quarantined passengers on the Westerdam cruise ship were allowed to disembark in Sihanoukville, Cambodia, after Holland American said no one aboard was sick.

However, it was later confirmed that an American woman who boarded a plane to Malaysia had contracted the virus.

Henry said about 20 Canadian passengers on the Westerdam travelled home to B.C. before the confirmation.

"All of them were identified at the border, and we have contacted them," said Henry.

They have been asked to stay in self-isolation at home, she says.

Henry said the first batch of Canadians — flown home from Wuhan, China — are almost finished their quarantined period and some will soon return home to B.C.

She said nobody has tested positive for the virus.

"I think this is our opportunity to welcome them back into our community," she said.