TORONTO -- On New Year鈥檚 Eve, the World Health Organization received an unusual message.

Cases of a mysterious illness of unknown origins with pneumonia-like symptoms were reported in Wuhan, a densely-populated city in central China with more than 11 million people.

Two months later, the newly-identified coronavirus -- COVID-19 -- has spread to nearly 40 countries, infected more than 80,000 people and killed over 2,700. Some countries have limited travel and implemented quarantines. Screening measures have been put in place in airports across the world, but there are doubts that such measures are helping stall the outbreak.

In Canada, 11 cases across two provinces: Ontario and B.C. Two of the three people to test positive in Toronto have recovered, including the very first Canadian case of the virus, while the third is still being treated. The sole individual to test positive in London, Ont. has also recovered.

In B.C., seven people have contracted the coronavirus. The first to be identified has recovered.

One of the largest outbreaks has been on a cruise ship docked outside of Yokohama, Japan. Of the 256 Canadians aboard the Diamond Princess ship when it was first quarantined, 48 Canadians have tested positive for COVID-19 and are receiving treatment in Japan. Evacuees from the ship arrived back in Canada on February 21 to begin a 14-day quarantine in Cornwall, Ont.

So far, no Canadians have died.

With new information emerging each day, here鈥檚 what we know so far about the outbreak.

WHAT IS A CORONAVIRUS?

The new illness, falls under a larger family of coronaviruses. First identified in humans in the mid-1960s, coronaviruses are zoonotic, which means they can be transmitted between animals and people. Many coronaviruses affect only one type of animal and cannot jump to humans.

Coronaviruses can be as minor as the common cold or life-threatening, as was the case with SARS.

The term gets its name from the Latin word 鈥渃orona,鈥 meaning halo or crown, which is what the virus looks when viewed through an electron microscope.

Symptoms of coronaviruses range from mild symptoms, such as coughing and sneezing, to more serious symptoms, such as shortness of breath, body aches and chills.

HOW IS THIS ONE DIFFERENT?

Scientists in China identified the new coronavirus on Jan. 7, eight days after it was first reported. They were also able to identify the genetic sequence of the virus and shared it with the international community -- a sign of transparency praised by the World Health Organization.

Primary symptoms of the new coronavirus include fever, cough, tightness of the chest and shortness of breath.

Despite being sequenced, the source of the virus has not been found, and new information continues to emerge regularly about its severity and spread.

With COVID-19, scientists believe that the virus originally had an animal source, but that now it is transmitted by human-to-human contact.

Studies have suggested numerous animals that could be related to the COVID-19 outbreak, such as bats, snakes and even pangolins. However, no specific animal origin has been confirmed yet.

COVID-19 is remarkable for its rapid spread. It is thought to be more contagious than related viruses such as SARS.

The sheer number of confirmed cases of the virus has continued to push the death toll up higher even though data released in mid-February showed that 80 per cent of the cases are mild.

The fatality rate for the virus is currently between two per cent and four per cent in Wuhan, and 0.7 per cent elsewhere in China. Globally, it is around two per cent.

HOW IS IT SPREAD?

The virus was initially linked to a handful of people in Wuhan, many of whom worked at a live animal market. Although scientists at first thought that it was spread only by animals, that changed when the head of a Chinese government expert team confirmed cases passed from one person to another.

It鈥檚 still not completely clear how easily the virus can be spread from one person to the next.

It was believed at first that the virus spread only when a person had started displaying symptoms (i.e. coughing or sneezing), but due to the rapid escalation of cases, scientists now believe that while infected individuals are the most contagious when symptomatic, there may be some spread of the disease possible before a person even knows they are ill.

However, according to the Centers for Disease Control and Prevention (CDC), the virus is thought to spread primarily through the droplets created when an infected person coughs or sneezes -- so close contact with an infected person is the main way to contract the disease. They add that touching a surface that has been recently sneezed on by an infected person may also be a way to contract the virus, but that it鈥檚 much less likely.

IS IT SIMILAR TO SARS?

The coronavirus has been compared to SARS, and the two illnesses do share some similarities.

SARS is considered a coronavirus, and it also began in China. Back in 2002, China withheld key information about how widely SARS had spread and the severity of the problem. More than 750 people were killed worldwide, including 44 in Canada.

However, in this case, early lab tests have ruled out a resurgence of SARS and its close cousin, Middle East respiratory syndrome (MERS).

SARS had a higher fatality rate than COVID-19 on a case by case basis, killing almost 10 per cent of those who contracted the virus. However, more people have died from COVID-19 overall because of how fast and far it has spread.

WHERE HAS THE CORONAVIRUS SPREAD?

The virus was discovered in Wuhan but has since spread across China and around the world. The federal government says Canadians should avoid all travel to Hubei province, where Wuhan is located.

The vast majority of cases are still in China, which has almost 78,000 cases confirmed. Some of the regions experiencing the largest outbreaks outside of China are South Korea, with almost 980 cases, the Diamond Princess cruise, with over 600 cases, and Italy, which has over 300 cases.

Countries with confirmed cases of the novel coronavirus include:

  • China
  • Canada
  • United States
  • South Korea
  • Italy
  • Japan
  • Singapore
  • Hong Kong
  • Thailand
  • Taiwan
  • Bahrain
  • Australia
  • Malaysia
  • Germany
  • Vietnam
  • United Arab Emirates
  • United Kingdom
  • France
  • Macau
  • Kuwait
  • Spain
  • Philippines
  • India
  • Russia
  • Oman
  • Austria
  • Afghanistan
  • Nepal
  • Cambodia
  • Israel
  • Belgium
  • Lebanon
  • Finland
  • Sweden
  • Croatia
  • Switzerland
  • Iraq
  • Egypt
  • Sri Lanka

WHAT IS HAPPENING AT CANADIAN AIRPORTS?

Airports in Toronto, Montreal and Vancouver have added electronic notifications for travellers asking anyone who has been to Wuhan and is experiencing flu-like symptoms to contact a border services agent.

Electronic kiosks at the three airports have also added an additional health screening question about the new virus.

In addition, there are now at major airports in Calgary, Edmonton, Winnipeg, Ottawa, Quebec City and Halifax.

Unlike authorities at U.S. airports, Canadian officials are not using thermal scanners to test for the virus. Questions have been raised about the effectiveness of airport screening because travellers infected with the virus may not be showing symptoms at the time of travel.

Any travellers returning from a trip outside of Canada have been asked by health officials to closely monitor their own health for 14 days after returning, and to notify local health authorities if they experience symptoms of illness. If they are returning from China鈥檚 Hubei province in particular, officials suggest they self-quarantine for 14 days.

Canada has not closed its borders or banned flights in and out of the country.

HOW IS INTERNATIONAL AIR TRAVEL AFFECTED?

The CDC has up recommending that people avoid nonessential travel to not only China, but South Korea as well, in the wake of an increase in cases there.

In addition, the CDC has put up travel alerts stating that those more likely to be at risk of falling ill -- such as children, the elderly and those with chronic illnesses -- should avoid travelling to Iran, Italy and Japan.

Several international airlines have altered or outright suspended flights to and from China, including Air Canada.

Air Canada, which run 33 flights each week to China, is cancelling select flights to China. The airline says the reduction is relatively small, and that affected customers will be notified.

British Airways has halted all flights to China, and American Airlines suspended flights to and from Shanghai and Beijing.

Britain鈥檚 Foreign Office has advised against all but essential travel to mainland China, and American Airlines cited a significant decline in demand for its decision to cancel flights.

Air India, Seoul Air and Lion Air have halted all flights to China. Service changes have also been made at Finnair, Cathay Pacific and Jetstar Asia.

WHAT IS THE RISK TO CANADIANS?

Canadian health authorities have repeatedly described the risk of COVID-19 spread in Canada as low.

Dr. Theresa Tam, Canada鈥檚 chief public health officer, called the outbreak 鈥渁 rapidly evolving situation鈥 but said that, for the moment, there is no cause for alarm.

Although more Canadians have been returning from China and from the Diamond Princess cruise ship, they have been placed into 14 day quarantines in order to monitor them for symptoms and minimize the risk.

On Feb. 25, 195 Canadians who had returned to Canada on a flight from Wuhan completed their quarantine at a Canadian Forces Base in Trenton and were confirmed to have no symptoms. The Chief Public Health Officer reiterated after their release from quarantine that , praising the work of provincial and territorial partners in keeping the spread of the virus controlled in Canada.