Cases of the coronavirus that originated in China's Wuhan are "doubling every five days" and dealing with the fallout is a "marathon, not a sprint", Britain's Health Secretary has said.
Matt Hancock told the UK House of Commons the virus will be "with us for at least some months to come" as the country warned all Brits in China to leave "if they can".
Latest figures from China on Tuesday show 425 people have been killed with more than 20,400 cases on the Chinese mainland.
• 'Disgusting virus spreaders': Parents get anonymous email telling kids to stay home
• Wuhan virus: What should air passengers and travellers know?
• Coronavirus: How new virus became a global epidemic
• New China virus details show challenge for outbreak control
Two people have died outside of China – in Hong Kong and the Philippines.
It comes as Wuhan converts three venues including a gym and exhibition centre known as "Wuhan Livingroom" into hospitals for the virus.
More than 3400 beds will be made available in addition to the extra 2600 beds that will be provided in two brand new hospitals, one of which is finished and one remains under construction.
NO PEAK YET, DOCTOR WARNS
Dr David Heyman – who led the World Health Organisation's (WHO) response to the 2002-03 SARS outbreak – said it's too early to tell when the new coronavirus will peak, but that it appears the disease is still on the increase.
He said the increase in Chinese cases recently can be partly attributed to the fact that Chinese officials expanded their search to include milder cases, not only people with pneumonia.
Dr Heymann declined to predict whether the virus would ultimately cause a pandemic, or worldwide outbreak. According to WHO, a pandemic requires sustained transmission of a disease in at least two world regions.
He said as the new virus starts to spread beyond China, scientists will gain a much better understanding of the disease.
"What we will see is the clearer natural history of the disease," he said.
"That will occur because all the contacts of people who have come into contact into these countries (where the virus has been exported) are being traced and watched very closely." SARS, or severe acute respiratory syndrome, is an illness from the same virus family as the current outbreak.
WEARING MASKS 'NOT ENOUGH'
The WHO said the virus does not yet constitute a pandemic, but rather "an epidemic with multiple foci," according to Sylvie Briand, head of WHO's Global Infectious Hazard Preparedness division.
She said outside of Hubei, the world is seeing "spillover cases" and wants to make sure we don't have a "second Hubei type of scenario."
She said stopping the spread would be "challenging" but thinks it can be done. Briand also warned against wearing masks as a "false sense of security" when hand washing is the key to stopping the spread of the infection.
"To stop transmission of this virus, it is very important that sick people wear masks" to avoid infecting others, she said, adding though the benefits of healthy people wearing masks as a precautionary measure were less clear.
The respiratory disease spreads through droplets, for instance when people sneeze or cough, or likely through direct contact with infected people or with objects they have touched.
"Masks alone are not enough. It is a package of measures that you have to put in place," she said.
"If people use the entire package, it is fine. If they just use masks, I think it is not enough."