What you need to know now about the coronavirus: International investigation begins this weekend

The latest:

• Death toll in mainlandChina reaches 1,523 with 143new deaths reported.
• 66,492total cases in mainland China, with 2,641new cases reported.
• 8th presumptive case identified in Canada.
• WHO's head of health emergencies stresses need to avoid "politicizing" the outbreak.
• Canadian health workers are assisting in Japan after 15 Canadians contracted the illness on the Diamond Princess cruise ship.
• Egypt's health authority has informed the WHO of its first case.

Led by the World Health Organization, an international investigation into the spread of novel coronavirus and its severity will begin in China this weekend.

WHO chief Tedros Adhanom Ghebreyesus, speaking from Kinshasa in the Democratic Republic of Congo, told reporters in Geneva Friday that the whole team will have touched down in China over the weekend.

"The goal of the joint mission is to rapidly inform the next steps in the COVID-19 response and preparedness activities in China and globally," he said, referring to the medical name for the acute respiratory disease caused by the virus.

Overall, China's National Health Commission said it had recorded 143new deaths on Friday,for a total of 1,523 across the mainland. It also reported 2,641new casesacross mainland China, taking the total number of people infected to66,492.

For context, influenza claims between 290,000 to 650,000 lives annually, and three to five million people experience severe cases of the illness.

Watch: How the coronavirus happened

How the coronavirus outbreak happened

5 years ago

Duration 5:32

As coronavirus cases in China climb to more than 66,000 and over 1,500 deaths, a look back at how the outbreak started and whether enough was done to stop it from spreading.

On Thursday, Chinese health authorities shared new case and fatality numbers that reflecteda change in how the illness is being diagnosed. Cases rose15,152 in one day after China widened its net to include cases that are clinically confirmed through chest scans, as opposed to diagnosed only through a lab test.

But public health experts wrestled with what exactly could be deduced from the numbers, given the shift in approach.

"If you change the way you count cases, that obviously confounds our capacity to draw firm conclusions about the effectiveness of the quarantine," said Dr. William Schaffner, an infectious disease expert at Vanderbilt University in the United States. "We have to interpret the numbers with great caution."

Dr. MikeRyan, head of the WHO's health emergencies program, stressed the importance of keeping politics out of discussions about the outbreak.

Ryan was askedto respond to a comment byLarry Kudlow, the director of U.S. President Donald Trump's Economic Council, who told reporters Thursday, "We're a little disappointed in the lack oftransparency coming from the Chinese."

Ryan said, "Please, let our scientists get on. Let our public health officials get on. We should try, all of us, to avoid politicizing this situation right now.

"From our perspective, we have a government that's co-operating with us, that's inviting in international experts, that's shared sequences with the world, that continues to engage with the outside community," he said of China.

New presumptive case in B.C.

A fifth presumptive case of the novel coronavirus has been identifiedin British Columbia, bringing the total number of cases in Canada to eight.

Provincial health officer Dr. Bonnie Henry said Friday a woman in her 30s returned from Shanghai in the past week through Vancouver's airport before travelling by car to her home in the Interior.

Henry said the woman wore a mask on the plane and contacted health officials when she had symptoms of an illness. She tested positivefor COVID-19 on Tuesday.

"We are very grateful and thankful that the people who are coming back from Hubei province and all over China are taking the advice seriously to self-monitor and to connect with us and make sure that they can be tested, assessed and cared for safely," she said.

The woman is in isolation at home, as are her close contacts, Henry said.

In all such cases, she said, a further test will be conducted at a national lab in Winnipeg to confirm the results obtained provincially.

Officials will be contacting passengers who sat three rows ahead and behind the woman on the flight that arrived from China, but the risk to them is "very, very low," she said.

The first person to be tested for the virus in the province is recovering well and has tested negative in the first of two tests needed to determine the patient no longer has the virusand isolation is no longer required, she said.

Canadian health workers assisting in Japan

Foreign Affairs Minister Franois-Philippe Champagnesays Canadian health workers are assisting in Japan after 15 Canadians contracted the novel coronavirus while on a cruise ship.

Champagne says three members of the Public Health Agency of Canada and two medical personnel from the Canadian Armed Forces have been sent to Yokohama, the Japanese port city where the Diamond Princess has been docked since last week.

Some 3,500 passengers on the ship are under quarantine and 218 people have tested positive for the coronavirus.

Champagne says the Japanese government will allow some elderly people to complete the rest of their quarantine period at another facility off the ship.

Meanwhile, Champagne says consular officials are assisting in Cambodia where another ship with 279 Canadians on-board was recently allowed to dock after being rejected from multiple other countries over fears of the new coronavirus.

There have been no reported case of the illness on board the Westerdam, and Champagne says officials will help Canadians with the process of returning home.

6 health care workers have died in China

China's National Health Commissionreported Friday that1,716 health workers had been infected and six had died as of Tuesday, with the number of infected staff rising.

"The duties of medical workers at the front are indeed extremely heavy; their working and resting circumstances are limited, the psychological pressures are great and the risk of infection is high," Zeng Yixin, vice-minister of the commission, told a news conference.

However, the WHO's Ryan said the numbers of infected health workers is sad but not alarming.

"Our understanding is that the cases amonghealth workers peaked in the third or fourth week of January and there's been a rapid fall-off in thenumber of cases that have occurred in health workers in the last two weeks," Ryan said.

He noted many of these health workers may have contracted the illness before the risks were known.

"Although it's a very tragic situation for those health workers and particularly for those who have lost their livesit is a lower percentage than has occurred in other coronavirus outbreaks," said Ryan.

How the disease is being treated

Chinese scientists are testing two antiviral drugs and preliminary results are due in weeks, while the head of a Wuhan hospital said plasma infusions from recovered patients had shown some encouraging preliminary results.

Finding the right treatment for a new disease is no small task.

Doctors and other health-care workers fighting the coronavirus outbreak in China don't have any specific treatments to use against this new virus. When they try to treat severe cases, they're walking a tightrope aiming to find just the right level of immune response to kill the virus without setting off other problems.

The virus causes respiratory symptoms, such as cough and fever.

Dr. Jerome Leis and his team treated Canada's first case at Sunnybrook Health Sciences Centre in Toronto last month. The man in his 50s initially had some X-ray findings that clinicians were concerned might worsen.

"After they were admitted, they did gradually improve and eventually their symptoms resolved completely," said Leis, referring to the man. "I think this story highlights, although we have seen poor outcomes related to this infection, including fatalities, those are the exception, not the rule."

Egypt reports 1st case

Egypt's Health Ministry has confirmed the first case of the new virus in the North African country.

In a statement Friday, Health Ministry spokesman Khaled Mugahed said the person was a "foreigner" who is carrying the virus but not showing any serious symptoms.

Officials were able to confirm the case through a follow-up program the government implemented for travellers arriving from countries where the virus has spread. The ministry statement said the person was hospitalized and in isolation.

The statement did not specify the person's nationality or what port of entry he or she arrived at in Egypt.

Experts and African leaders have expressed concern that should the virus spread there, it might wreak havoc among less developed countries with fewer health resources.

Previously the number of countries affected outsideChina was steady at 24.