Chinese authorities are set to suspend all outbound transport from Wuhan as the city battles to halt the outbreak of a deadly new virus that has so far killed 17 people.
Bus, subway, ferry and long-distance transport networks from the city, which is home to nearly 9 million people, will be stopped from 10am local time (2am GMT) on Thursday. The airport and train stations will also be closed to outgoing passengers.
Meanwhile, those living in Wuhan have been asked not to leave the city and to avoid crowds and minimise public gatherings.
The measures come after the UK government announced that people arriving at Heathrow airport from Wuhan would be met by health teams to check passengers for symptoms of coronavirus, while the Foreign and Commonwealth Office has advised against travelling to Wuhan.
There are currently more than 540 confirmed cases of coronavirus, according to the official China Daily newspaper, and Chinese health authorities have warned the virus could mutate and spread further.
Li Bin, deputy director of the National Health Commission, told a news conference there has “already been human-to-human transmission and infection of medical workers”.
He added: “Evidence has shown that the disease has been transmitted through the respiratory tract and there is the possibility of viral mutation.”
The coronavirus, which can cause pneumonia, comes from a family of viruses that can cause the common cold as well as more serious illnesses such as the Sars outbreak, which spread from China to more than a dozen countries between 2002-2003 and killed around 800 people.
Four cases have been confirmed in Thailand, while Japan, South Korea and the United States have each reported one case. All of those who fell ill were people from Wuhan or those who had recently travelled to the city.
On Wednesday, Hong Kong and Macau also reported their first cases.
“The situation is under control here,” Thailand’s public health minister, Anutin Charnvirakul, said, adding there were no reports of the infection spreading. “We checked all of them: taxi drivers, people who wheeled the wheelchairs for the patients, doctors and nurses who worked around them.”
Travel agencies organising trips to North Korea said the country had banned foreign tourists because of the outbreak. Most tourists to North Korea are Chinese or travel to the country through neighbouring China.
Other countries have stepped up screening measures for travellers from China, especially those arriving from Wuhan. Worries have been heightened by the coming of the lunar new year holiday rush, when millions of Chinese travel at home and abroad.
In the UK, public health officials will meet three direct flights due to arrive into London Heathrow.
Health minister Baroness Blackwood of North Oxford announced there will be “enhanced monitoring” of all flights arriving in the UK from China from Wednesday, and any potential patients will be isolated if necessary.
She said the government is closely monitoring the development of the virus but added the risk to UK citizens is “currently low” and the country is “well prepared”.
The government updated its travel advice on Wednesday evening, advising against all but essential travel to Wuhan.
A spokesperson for the Foreign and Commonwealth Office said: “In light of the latest medical information, including reports of some person-to-person transmission, and the Chinese authorities’ own advice, we are now advising against all but essential travel to Wuhan.
“The safety and security of British nationals is always our primary concern, and we advise British nationals travelling to China to remain vigilant and check our travel advice on gov.uk.”
Gao Fu, an academic at the Chinese Academy of Sciences and head of the Chinese Centre for Disease Control, told reporters: “We are still in the process of learning more about this disease.”
Mr Gao said officials are working on the assumption the outbreak was caused by human exposure to wild animals being sold illegally at a food market in Wuhan, and the virus is mutating. Mutations can make the virus spread faster or make people sicker.
Jiao Yahui, a health commission official, said “the disease will continue to develop”, adding: “It has developed different features compared with the early stage, and the prevention and precautionary measures need to change accordingly.”
Earlier this week, health officials confirmed the disease can spread between humans after finding two infected people in Guangdong province, in southern China, who had not been to Wuhan.
Fifteen medical workers also tested positive for the virus, the Wuhan Municipal Health Commission has said.
Fourteen of them, one doctor and 13 nurses, were infected by a patient who had been hospitalised for neurosurgery but also had the coronavirus.
“This is a very profound lesson, which is that there must not be any cracks in our prevention and control,” Wuhan’s mayor, Zhou Xianwang, said about the infections of the medical workers in an interview with state broadcaster CCTV .
Additional reporting by agencies