Beijing, January 22: A new virus that has killed nine people, infected hundreds and reached the United States could mutate and spread, China warned Wednesday, as authorities scrambled to contain the disease during the Lunar New Year travel season.

The coronavirus has caused alarm for its similarity to SARS (Severe Acute Respiratory Syndrome), which killed nearly 650 people across mainland China and Hong Kong in 2002-2003. China Virus SARS Contagious Between People, Says Chinese Government Expert.

In Wuhan, the epicentre of the outbreak, authorities cancelled large public events, called on visitors to stay away and urged residents not to leave the central Chinese city of 11 million people.

The illness is mainly transmitted via the respiratory tract and there "is the possibility of viral mutation and further spread of the disease", National Health Commission vice-minister Li Bin told a news conference in Beijing.

He added that 1,394 people are still under medical observation, while 765 others have been discharged.

The World Health Organization (WHO) will hold an emergency meeting Wednesday to determine whether to declare a rare global public health emergency over the disease, which has now been detected in the United States, Taiwan, Thailand, Japan, South Korea and Macau.

The first case in the United States -- a Seattle resident in his 30s -- is in good condition, American officials said.

The Chinese government has classified the outbreak in the same category as the SARS epidemic, meaning compulsory isolation for those diagnosed with the illness and the potential to implement quarantine measures.

But they still have not been able to confirm the exact source of the virus, which has infected at least 440 people across the country.

"We will step up research efforts to identify the source and transmission of the disease," Li said, although he said experts believe "the cases are mostly linked to Wuhan".

Plane passengers are facing screening measures at five US airports and a host of transport hubs across Asia.

North Korea will ban foreign tourists entirely to protect itself against the virus, according to a major tour operator.

- Virus source -

A prominent expert from China's National Health Commission confirmed this week that the virus can be passed between people.

However, animals are suspected to be the primary source of the outbreak.

"We already know that the disease originated from a market which conducted illegal transaction of wild animals," said Gao Fu, director of the Chinese centre for disease control and prevention.

He said it was clear "this virus is adapting and mutating".

Countries have been intensifying efforts to stop the spread of the pathogen -- known by its technical name 2019 Novel Coronavirus (2019-nCoV) -- as the number of cases jumped.

This week, China celebrates the Lunar New Year, the most important event in the Chinese calendar, with hundreds of millions of people travelling across the country to celebrate with family. Many also venture abroad.

- Containment -

On Wednesday, the commission announced measures to contain the disease, including sterilisation and ventilation at airports and bus stations, as well as inside planes and trains.

People are being urged to wash their hands regularly, avoid crowded places, get plenty of fresh air, and wear a mask if they have a cough.

Anyone with a cough or fever was urged to go to hospital.

Surgical masks and antibacterial products were starting to sell out on some popular online sites and pharmacies.

"These days, I wear masks even in places that are not too crowded, although I wouldn't have done so in the past," said Wang Suping, 50, who works at a Beijing arts school.

At the city's main international airport, the majority of people were wearing masks.

Hong Kong flag carrier Cathay Airlines said they agreed to allow staff to wear surgical masks on mainland China flights, adding they would offer masks and antiseptic wipes to passengers travelling from Wuhan to the city.

Wuhan police were conducting vehicle spot checks for live poultry or wild animals leaving and entering the city, state media said. Officials also screened people on roads, the airport and the train station for fevers.

"If it's not necessary we suggest that people don't come to Wuhan," Mayor Zhou Xianwang told state broadcaster CCTV.

The local government has cancelled major public activities and banned tour groups from heading out of the city.

Hong Kong and British scientists have estimated that between 1,300 and 1,700 people in Wuhan may have been infected.

(The above story first appeared on LatestLY on Jan 22, 2020 04:21 PM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).