Australia is ramping up airport screening of passengers arriving from China, after authorities in that country confirmed that a new strain of coronavirus has been passed from person to person, sparking fresh fears of a global epidemic.

Key points: A Brisbane man who recently returned from Wuhan is being tested for the virus

A Brisbane man who recently returned from Wuhan is being tested for the virus The total number of worldwide cases of the virus is 222

The total number of worldwide cases of the virus is 222 There is no vaccine for the new virus

China's National Health Commission said the virus, which causes pneumonia, had spread to new cities and that some medical staff had been infected by patients, the country's official Xinhua news agency said.

On Tuesday morning, it was confirmed a man was in isolation in his Brisbane home as Queensland Health authorities ran tests on whether he was carrying the new strain.

The outbreak, which began in the central city of Wuhan, has now spread to other cities including the capital Beijing and Shanghai. Five new cases were confirmed in Beijing and 14 more in Guangdong province. A new case was reported in Shanghai.

The number of cases has tripled to more than 220, and three people are known to have died.

Cases have been reported in Thailand, South Korea and Japan, all involving people who had visited Wuhan.

Today Australia's chief medical officer said the risk to Australia was low but warned that the disease had an incubation period of about a week, during which time symptoms would not be apparent.

He said stricter screening measures would apply particularly to the three flights a week that arrived in Sydney from Wuhan.

Those flights will now be met by border security and biosecurity staff as well as New South Wales Health officials.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 23 seconds 23 s A video circulating on Chinese social media apparently shows medics checking temperatures of passengers on a flight from Wuhan to Macau

"We're doing some careful modelling to see if there are any other flights from China that have a high proportion of Wuhan-origin passengers, and we may consider expanding that too," he said.

"But we have to do the analysis to find out where they come from, because there are apparently 160 flights from China a week."

There is no vaccine for the new virus, and China's President Xi Jinping said curbing the outbreak and saving lives was now the top priority.

"People's lives and health should be given top priority and the spread of the outbreak should be resolutely curbed," he was quoted as saying by state television.

Adding to the difficulties of containing the virus, hundreds of millions of Chinese people will be travelling domestically and abroad during the Lunar New Year holiday that starts this week.

Authorities around the globe, including in the United States and many Asian countries, have also stepped up screening of travellers from Wuhan.

Medical staff at Wuhan Jinyintan Hospital, where patients with pneumonia caused by the new strain of coronavirus are being treated. ( Reuters )

In a series of tweets, Prime Minister Scott Morrison said chief medical officer Brendan Murphy briefed him on the coronavirus on Tuesday.

He said precautions were being taken to protect Australians, adding: "We will be raising the level of our travel advice for Wuhan City to level 2 — exercise a high degree of caution. I urge all Australians travelling to check the DFAT Smart Traveller website for specific updates."

He said state medical workers had initiated measures to mitigate the risk of infectious people entering the country.

"We are well prepared to respond to this situation and we will continue to monitor and take action where necessary," he added.

Specialist in infectious disease epidemics and Wellcome Trust global health charity director, Sir Jeremy Farrar, said there was a need to be vigilant.

"Wuhan is a major hub and with travel being a huge part of the fast-approaching Chinese New Year, the concern level must remain high," he said.

"There is more to come from this outbreak."

The virus belongs to the same family of coronaviruses as Severe Acute Respiratory Syndrome (SARS), which killed nearly 800 people globally during a 2002-03 outbreak that also started in China.

Its symptoms include fever and difficulty in breathing, which are similar to many other respiratory diseases and pose complications for screening efforts.

Pedestrians wear protective masks as they walk through a shopping district in Tokyo after the first case of pneumonia detected in Japan. ( AP: Eugene Hoshiko )

Virus spreads beyond China's borders

Overnight South Korea confirmed its first case, a 35-year-old Chinese national who had travelled from Wuhan, the fourth patient reported outside China.

Thailand has reported two confirmed cases of the virus, both of whom were Chinese tourists from Wuhan.

Japan also confirmed one case of a Japanese citizen who visited Wuhan.

A report by London Imperial College's MRC Centre for Global Infectious Disease Analysis estimated that by January 12 there were 1,723 cases in Wuhan City with onset of related symptoms. Chinese health authorities have not commented directly on the report.

"This outbreak is extremely concerning. Uncertainty and gaps remain, but it is now clear that there is person-to-person transmission," Sir Jeremy said.

The World Health Organisation said on Monday that "an animal source" appeared most likely to be the primary source of the outbreak and that some "limited human-to-human transmission" occurred between close contacts.

A computer artwork of a coronavirus, named after the corona, or crown, of surface proteins (outer dots) that are used to penetrate a host cell. ( Science Photo Library: PASIEKA )

Shares in pharmaceutical firms and mask makers in China surged because of the outbreak.

"Who knows how many people who have been to Wuhan may be unaware that they have already been infected?," said one commentator on Chinese social media platform Weibo

Many of the initial cases of the coronavirus were linked to a seafood market in Wuhan, which has been closed as authorities investigate.

The state-run Global Times newspaper said in an editorial the Government needed to disclose all information and not repeat the mistakes made with SARS.

Chinese officials covered up the SARS outbreak for weeks before a growing death toll and rumours forced them to reveal the epidemic.

"We have made great strides in medicine, social affairs management and public opinion since 2003," the editorial said.

"Concealment would be a serious blow to the government's credibility and might trigger greater social panic."

A person wearing a white biohazard suit at the hospital treating patients in Wuhan.

ABC/wires