The coronavirus outbreak that began in the central Chinese city of Wuhan has killed 56 people in China and infected more than 2,000 globally, most of them in China.
The virus has caused alarm because it is still too early to know how dangerous it is and how easily it spreads between people. And because it is new, humans have not been able to build any immunity to it.
Here is what we know so far:
* As of midnight in Beijing on Jan 25, the death toll in China had risen to 56, authorities reported. Some 1,975 people in China had been infected with the virus.
* The coronavirus transmission ability is getting stronger and infections could continue to rise, China's National Health Commission said.
* China bans wildlife trade nationwide in markets, supermarkets, restaurants, and e-commerce platforms, authorities said.
* The previously unknown coronavirus strain is believed to have emerged late last year from illegally traded wildlife at an animal market in Wuhan.
* Thailand has reported five cases; Australia and Singapore have reported four; the United States, France, Japan, Taiwan and Malaysia three; Vietnam and South Korea two apiece; and Canada and Nepal one.
* Beijing will delay reopening the city's kindergartens, schools and universities, state-owned China National Radio (CNR) said on its official Weibo page.
* Taiwan further tightens restrictions on visitors from China, suspending entry for many apart from business travellers and a few other exceptions.
* Hong Kong's popular amusement parks Disneyland and Ocean Park are closed from Jan. 26, state media CCTV reported.
* The World Health Organisation (WHO) said that while the outbreak was an emergency for China, it was not yet a global health emergency.
* Symptoms include fever, cough and difficulty breathing.
* China says the virus is mutating and can be transmitted through human contact.
* Two separate scientific analyses of the epidemic say each person infected is passing the disease on to between two and three other people.
* Those most affected are older people and those with underlying health conditions.
* Three research teams have begun work on developing potential vaccines, the Coalition for Epidemic Preparedness Innovations said. Scientists hope to be testing the first possible vaccines in three months' time.
* China announced further travel curbs on Saturday. Ride-hailing giant Didi Chuxing said it was halting inter-city services to and from Beijing from Sunday, while the capital will also stop running inter-province shuttle buses.
* Wuhan, a city of 11 million, is under severe travel restrictions, with urban transport shut and outgoing flights suspended.
* China has advised people to avoid crowds and more than 10 cities in the central province of Hubei, where Wuhan is located, have suspended some transport.
* Tourist access to Beijing's Forbidden City closed and large gatherings cancelled, including two Lunar New Year temple fairs, and closed part of the Great Wall.
* Hong Kong has declared an emergency and will extend school holiday closures until Feb 17. The city also cancelled all official Lunar New Year celebrations and official visits to mainland China.
* Airports around the world have stepped up screening.
* Some experts believe the virus is not as dangerous as the 2002-03 Severe Acute Respiratory Syndrome (SARS) that killed nearly 800 people, and Middle East Respiratory Syndrome (MERS), which has killed more than 700 people since 2012.