China virus outbreak: What we know, and don’t, about the mysterious illness so far

Click to play video: 'Preparing for the arrival of the Coronavirus from China'
Preparing for the arrival of the Coronavirus from China
WATCH: Preparing for the arrival of the Coronavirus from China – Jan 21, 2020

At the end of 2019, health authorities in China began reporting cases of a mysterious illness with pneumonia-like symptoms.

Now, after just a few short weeks, there are more than 500 cases in China and nearby countries, with 17 deaths reported as of Jan. 22.

Airports have begun checking passengers for the illness, and the virus is even being blamed for fluctuations in the stock market.

The World Health Organization met this week to discuss whether it constituted a global health emergency. They concluded that it was “too early” though they may change their minds later.

“Make no mistake, this is now an emergency in China, but this has not yet become a global health emergency,” said Dr. Tedros Adhanom Ghebreyesus, director-general of the WHO, on Thursday.

“It may yet become one.”

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Here’s what you need to know about the coronavirus from Wuhan, China.

What is it?

So far, symptoms of the virus include fever and difficulty breathing, the World Health Organization said. The virus can also cause pneumonia.

The virus is part of the coronavirus family, said Dr. Amesh Adjala, a senior scholar at the Johns Hopkins Center for Health Security. Coronaviruses are a “large family” of viruses, he said, “that are responsible for about one-quarter of our common colds that we have every year. So it’s a very ubiquitous virus.”

But the vast coronavirus family also includes Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), which caused 774 deaths during an outbreak in 2002-03, and caused significant disruption in Canada.

How did it start?

The first cases were reported on Dec. 31, 2019, in the central Chinese city of Wuhan.

“It’s likely that it emerged from an animal market in China, jumping from a non-human host to a human,” said Dr. Isaac Bogoch, an infectious disease specialist at Toronto General Hospital.

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The first cases appear to have been linked to a seafood market, where people also sold other kinds of animals, according to Chinese officials.

Since then, cases have appeared in other Chinese cities, including Beijing, and the nearby countries of Thailand, Japan, South Korea and Taiwan. Many of the people had never visited that seafood market.

Click to play video: 'China reports new virus cases, raising concern globally'
China reports new virus cases, raising concern globally

The Centers for Disease Control and Prevention announced Jan. 21 the first U.S. case of the coronavirus: a resident of Washington state.

How serious is this?

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Although it likely originated in animals, Bogoch said, Chinese authorities confirmed Jan. 20 that the virus can now be passed between humans, which would make it spread much more easily in the general population.

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Some of the human-to-human transmissions were from patients to the doctors and nurses who were attending them, according to WHO. Reuters reported Tuesday that one of the doctors originally sent to investigate the outbreak had since contracted it.

But, Bogoch said, there is still a lot we don’t know about the virus.

“How many people are infected with this in China?” he asked. “If there are enough cases that cases are now being exported internationally to Japan, Thailand and South Korea, it’s likely that the number of cases in China is higher than what’s being reported.”

This might not be because China is intentionally hiding anything, he said. It’s possible that many people aren’t sick enough to seek medical attention, so are never seen and counted by doctors.

A Jan. 17 report by the MRC Centre for Global Infectious Disease Analysis at Imperial College London estimated that given Wuhan’s size and importance as a travel hub, there would be around 1,700 cases of the virus — far more than reported at the time, though this is just an estimate.

It’s worth noting that there are currently no vaccines or antiviral treatments for coronaviruses, something Adjala thinks should be addressed. “If we had a vaccine, if we had an antiviral, it would take the threat level down multiple notches.”

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This particular virus is also very new, and vaccines can take years to develop.

Click to play video: '584 confirmed cases of people infected with coronavirus, including 17 deaths: WHO officials'
584 confirmed cases of people infected with coronavirus, including 17 deaths: WHO officials

Two of the big unanswered questions early in the outbreak were how severe the disease was and what proportion of those infected would develop serious symptoms, Bogoch said.

The WHO began answering these questions Thursday. According to them, around one-quarter of those infected experience severe disease, though for most people it causes milder symptoms.

Bogoch notes, however, that these numbers are very preliminary and are likely based on those people who were diagnosed, meaning that they were sick enough to seek medical care. There might be other people with the virus who just haven’t been sick enough to go to the doctor, he said. “What we don’t really know is the denominator.”

Most of those who died had underlying health conditions, like hypertension or diabetes, which weakened their immune systems, said WHO director-general Ghebreyesus.

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Human-to-human transmission appears to have been limited to family groups and health care workers, he said.

Click to play video: 'Cause of novel coronavirus, spread, clinical features remain unknown: WHO'
Cause of novel coronavirus, spread, clinical features remain unknown: WHO

But there are still unanswered questions. “We don’t know the source of this virus, we don’t understand how easily it spreads, and we don’t fully understand its clinical features or severity,” he said.

Is this the new SARS?

Wuhan has a lot of the ingredients that could make it a “good” outbreak source, Adjala said. It has a “high population, connection to many different cities and live animal markets where we know that viruses can jump from animals to humans.”

But, he said, in this case, the system for detecting viruses appears to be “working well.”

“This isn’t a time for panic, but it is a time for people to be alert,” he said. “It really illustrates how to effectively contain an infectious disease outbreak by alerting neighbouring countries.”

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One difference from the SARS epidemic is that, unanswered questions aside, China has been far more open about the outbreak than it was about SARS, Bogoch said. For example, China quickly shared the genetic sequence of the virus, which led to researchers in Germany developing a rapid test for the disease.

Bogoch also thinks that our public health systems are better equipped to handle an outbreak than they were in 2002 during SARS.

“In 2020, we’re far better positioned than we were in 2002 to manage an outbreak like this,” he said. “So for example, our diagnostic testing is certainly a lot better.”

WATCH: WHO says new China virus could spread, warns hospitals worldwide (Jan. 14, 2020)

Click to play video: 'WHO says new China virus could spread, warns hospitals worldwide'
WHO says new China virus could spread, warns hospitals worldwide

The WHO has issued guidelines to hospitals on managing a possible outbreak, and airports around the world, including Canada, have started screening passengers from Wuhan. In Canada, so far, these measures are essentially asking travellers whether they’re experiencing any illness, according to the Public Health Agency of Canada (PHAC).

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“I think the world is pretty sensitized to this because we’ve dealt with SARS, MERS, several Ebola outbreaks, Zika, chikungunya, H1N1. We’ve seen a number of epidemics affecting the world in a relatively short time — only 18 years,” Bogoch said.

“So I think many places are sensitized to this and are bracing for potential importation of cases.”

Click to play video: 'Preparing for the arrival of the Coronavirus from China'
Preparing for the arrival of the Coronavirus from China

PHAC notes that there have been no Canadian cases reported so far. “The Public Health Agency of Canada is monitoring the situation, and the risk to Canada and to Canadians continues to be low,” the agency said in a statement Monday.

The best advice for individuals right now, Adjala said, is to avoid visiting live animal markets in Wuhan, and avoid people with respiratory illnesses, though he notes that can be difficult in the middle of flu season.

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The WHO recommends ordinary measures like handwashing and covering your mouth when you cough to protect yourself from this and other respiratory viruses.

— With files from Reggie Cecchini and Reuters

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