It is a potentially deadly virus that has already claimed the lives of more than 80 people and put millions of others into lockdown as China tries to control coronavirus.
A respiratory disease, coronavirus has already spread out of the China with cases now identified in Thailand and the US.
Health bosses in the UK have already warned that it's "more than likely" there are already cases of the infection in Britain as more than 50 people have been tested so far.
England's chief medical officer Professor Chris Whitty said there was a "fair chance" cases would emerge in Britain as the overall number reported around the world climbed to about 2,744.
The Department of Health insists the risk to people on the UK remains low but stress that the situation is being monitored closely by the government.
In China, at least 10 cities - and 33million people - have already been put in lockdown in a bid to stop the spread of the illness.
The first was Wuhan, which is where coronavirus is thought to have originated, and major tourist attractions have been closed to visitors.
Among these are Shanghai Disneyland and authorities are working round the clock to build new hospitals to treat the sick.
A new 1,000-bed hospital is due to open on Febraury 3.
Huge holiday events for Chinese New Year have also been cancelled, including a celebration in Bejing, which normally attracts huge crowds.
Transport in and out of some of the affected areas in China has already been closed off and the government is advising Brits against travelling to others.
Arrangements are also being made to bring UK nationals in the affected areas back to the UK.
Other countries are also making arrangements to bring people home.
A British teacher who lives in the centre of the outbreak has claimed he wasn't tested for coronavirus when he returned to Britain last week.
David Marland lives just five minutes from a live animal and seafood market in Wuhan where it is believed the SARS-like virus was passed to humans.
Experts from the World Health Organsation have also warned that the number of infected people could double every six days.
Coronavirus, unlike other deadly epidemics SARS and Ebola, can be spread before the person infected is showing any symptoms, making it harder to contain.
It means people with coronavirus may be unaware they are infected as they go about their daily routine.
China's health minister Ma Xiaowei made the announcement yesterday.
Dr William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center, said: "This is a game changer, it means the infection is much more contagious than we originally though.
"This is worse than we anticipated."
It is thought, but has not been confirmed, that coronavirus is spread via animals and China has now banned the trade of wild animals.
