The new strain of coronavirus has reached Europe after France confirmed three cases.
A 48-year-old man is being treated in a Bordeaux hospital in the southwest of the country after testing positive.
He had passed through the Chinese city of Wuhan - the epicentre of the outbreak - before arriving in France on Wednesday.
Two other people are in hospital in Paris. They also travelled to China and are believed to belong to the same family.
Health minister Agnes Buzyn said France has developed a test doctors can use to quickly diagnose patients and this was one reason why it was the first European nation to confirm cases.
Ms Buzyn predicted there would probably be more positive tests in her country.
It comes as the United States announced a second case after a woman was found to have contracted the strain.
She is in her 60s and is being treated in a Chicago hospital where she is reportedly doing well. She had travelled to Wuhan in December before flying home to Illinois.
China announced today it is building a new 1,000-bed hospital in just six days to treat victims of the virus.
Work has started on the structure in Wuhan in the style of a facility Beijing constructed during the SARS epidemic 17 years ago.
Machinery including 35 diggers and 10 bulldozers arrived at the site on Thursday night, with the aim of the hospital being operational by 3 February.
It comes as the coronavirus death toll in China increased to 41 and the number of confirmed cases around the world was 1,287.
Lockdowns to contain the new virus have been extended to at least 10 cities - including nine in Hubei province - effectively isolating 33 million people.
Restrictions include the suspension of public transport services, while some cities have also shut public venues such as temples and cinemas.
Authorities have warned of more stringent and targeted measures.
"The spread of the virus has not been cut off. Local authorities should take more responsibility and have a stronger sense of urgency," state broadcaster CCTV said.
British grandmother trapped in Wuhan
Veronica Theobald, from Lancaster, is visiting her grandson, Kharn Lambert, who has lived in the city for five years.
The 81-year-old has chronic obstructive pulmonary disease and has not left the house where she is staying in over a week.
She was due to fly back to England on Monday - but she is unable to with the city in lockdown.
Mr Lambert, a PE teacher, said: "There is no knowing how long she will have to stay here, and I'm worried about her running out of the medication she needs for her health so I'm in constant contact with the British embassy.
"I do worry if I have to go out for whatever reason that I will bring something back into the house and she will become infected and fall ill.
"My family at home are extremely concerned about her, but I'm trying hard to reassure them that I am taking the best care of her as I can."
Is it a global health emergency?
The World Health Organisation (WHO) has declared the outbreak an emergency but said it was "too early" to consider it a "public health emergency of international concern" given "its restrictive and binary nature".
WHO chief Dr Tedros Adhanom Ghebreyesus said: "Make no mistake, though, this is an emergency in China.
"But it has not yet become a global health emergency. It may yet become one."
What do we know about the new virus?
There is no vaccine for the new viral infection, which can cause pneumonia and can be passed from person to person .
The symptoms include fever, coughing and difficulty breathing.
Though the origin of the virus has yet to be identified, the WHO has said the primary source is probably an animal.
Coronaviruses are a large family of viruses ranging from the common cold to severe diseases such as SARS - which killed nearly 800 people during the 2002-03 outbreak.
When a new strain emerges that has not yet been identified, as with the current outbreak, it becomes known as a novel coronavirus (nCoV).
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What about the rest of the world?
Overseas, five cases have been found in Thailand, three in Singapore and Taiwan, two in the US, Hong Kong, Japan, South Korea, Vietnam and the autonomous region of Macau, and one in Nepal.
In Singapore, schools have asked parents to declare their overseas holiday plans as authorities screen travellers at air, land and sea checkpoints to combat the spread of the deadly virus.
Airports around the world - including in Dubai, Australia and South Africa - have stepped up screening of travellers arriving from affected regions.
In the UK, 14 people have been checked for coronavirus - all have tested negative, Public Health England said.
Measures are also in force in the UK to guard against the virus, including taking aircraft to a special designated area of Heathrow's Terminal 4 .