The outbreak of a new coronavirus stemming from Wuhan, China, has killed nine people and afflicted more than 400 others ahead of the Lunar New Year holiday during which hundreds of millions of people are expected to travel. As of Wednesday morning, it has now spread beyond Asia, with one confirmed case found in Washington State, U.S. Officials confirmed that the new mystery virus can spread between humans and said 15 medical staff have now been infected, stoking fears about an international pandemic and prompting airport authorities around the world to step up screening of travelers arriving from China. The outbreak could hit the economy, experts warned as they pointed to the fallout from the deadly SARS crisis in 2003.

What is coronavirus?

Where does Coronavirus come from?

As of Tuesday evening, authorities have confirmed more than 400 cases, with most of those occurring in the Hubei province of China and its provincial capital of Wuhan, a city of 11 million people. The outbreak was also spreading to other cities, with 14 cases in southern province of Guangdong, five in the capital Beijing, five in the eastern province of Zhejiang, two in Shanghai and two in Tianjin City.

Cases have also been reported in Thailand, South Korea and Japan. Taiwan confirmed its first case Tuesday evening in a 55-year-old Taiwanese woman who had returned from Wuhan the night before. On Tuesday, the WHO warned the coronavirus was likely to spread. "More cases should be expected in other parts of China and possibly other countries in the coming days," said WHO spokesman Tarik Jasarevic. Asked by Reuters why the WHO expected higher numbers, Jasarevic said new cases would appear as China steps up monitoring. The outbreak comes ahead of the Lunar New Year holiday period this week, when millions of Chinese will travel domestically and overseas — heightening the risk of more transmissions. The WHO, which does not advise travel restrictions at this time, said it will convene an emergency committee on the virus on Wednesday to consider declaring an international health emergency. @WHO: BREAKING: WHO Director-General @DrTedros will convene an Emergency Committee on the novel #coronavirus (2019-nCoV) under the International Health Regulations. The Committee will meet on Wednesday, 22 January 2020.

How does it compare with SARS?

The outbreak has sparked alarm because the disease is in the same family of viruses as severe acute respiratory syndrome. SARS, which emerged in China in 2002 and was identified in 2003, killed nearly 800 people worldwide. It hit Asian cities such as Hong Kong, Singapore, Taipei and Beijing the hardest and triggered a severe downturn in the region. "I remember the SARS outbreak very, very clearly and the impact it had. These things have an enormous hit on economies," said Rob Carnell, Dutch bank ING's chief economist, adding that some countries even slipped into recession. "It is not inconceivable that if Wuhan becomes more widely spread, and starts to claim more lives, that it will result in a similar response," added Carnell.

At the time, the rapid spread of SARS was blamed on a lack of transparency by the Chinese authorities. In an opinion editorial published Sunday, state tabloid Global Times wrote, "In the early moments of SARS, there was concealment in China. This must not be repeated." This time, however, experts say China has moved more rapidly to deal with the crisis and that the virus appears to be less lethal than SARS. Chinese President Xi Jinping said Monday that containing the spread of the coronavirus should be a "top priority," according to state media. "Government and World Health Organization reports indicate that the virus is both less virulent and less deadly than SARS. The response from Beijing is also far faster this time than it was in 2002-04," said Rory Green, economist for China and South Korea at research firm TS Lombard.

Could it impact the economy?