The death toll from the coronavirus outbreak in China has jumped to 17 – a near doubling in the past 24 hours.

Australian border and health authorities are on high alert in Sydney where a flight from the Chinese city of Wuhan – at the epicentre of the outbreak – is due to arrive at 11.35am on Thursday.

On standby are four NSW Health doctors and nurses along with virology experts from Westmead Hospital and elsewhere.

The team will be wearing masks and gloves to examine anyone with symptoms. 

“If it looks like they may have an infection … we can arrange for testing and management of that person right away,” NSW Health protection executive director Jeremy McAnulty said.

But identifying potential carriers at the airport is “not foolproof by any means” because people who’ve been exposed to the virus may not display symptoms for days, Mr McAnulty said.

Australians have been told to reconsider travelling to Wuhan as the Chinese city battles to contain the outbreak.

Advice on the government’s Smart Traveller website has been updated to reflect the gravity of what the World Health Organisation has called a complex and evolving situation.

“We now advise all Australians to reconsider their need to travel to Wuhan,” the website warns.

The number of confirmed cases in mainland China has reached 546 – up from more than 300 announced the previous day.

Eight more people from across the world have been diagnosed with this new form of viral pneumonia that until Wednesday had killed nine patients.

These figures, released by officials in China’s Hubei province, could spiral in the days ahead, with hundreds of thousands expected to travel from major cities to family homesteads for the Lunar New Year celebration.

In a desperate attempt to stop the spread of this virus, the nine million people in Wuhan won’t have access to any public transport as the city shuts down everything from buses and train stations to ferries and airports.

An emergency meeting at the World Health Organisation in Geneva has convened to decide whether to declare a “public health emergency of international concern”. They are expected to make the announcement on Thursday.

Health authorities have mandated that anyone who chooses to go out in public in Wuhan – where the virus originated from – must wear a face mask.

Citizens wear masks to defend against the new virus. Photo: Getty

That includes everything from shopping malls to waiting rooms and parks.

“People who don’t obey the requirements shall be dealt with by authorities in accordance with their respective duties and laws,” a notice by Wuhan’s municipal government read.

It comes after the boxing qualifying tournament for the Tokyo Olympics, which was scheduled for next month in Wuhan, was cancelled due to fears over the deadly virus.

CNN cited scientists at Imperial College London who estimate that some 4000 people are likely to have been infected in Wuhan since January 18.

Incidents of the disease have been reported in Japan, the Philippines, South Korea, Taiwan, Thailand and the US, as well as in the Chinese territories of Hong Kong and Macau.

AFP map of China, Japan, Thailand, South Korea, and Wuhan Seafood Market, identified as the centre of an outbreak of a SARS-like virus known as the 2019 Novel Coronavirus pic.twitter.com/BO0HCIcj2P

— AFP News Agency (@AFP) January 22, 2020

Several countries increased border health checks to guard against the disease’s spread, including Australia, the US, the UK and Russia.

North Korea has temporarily closed its border to all foreign tourists in response to the outbreak, according to a travel agency that operates tours to the country.

The new coronavirus belongs to the same family of viruses that caused Severe Acute Respiratory Syndrome (SARS), a disease that killed 800 people globally in a 2002-03 pandemic that also started in China.

Scientists in China said the new coronavirus may have been transmitted during the illegal trade of wild animals.

China’s Disease Control and Prevention Centre director Gao Fu said the virus is believed to have originated at a market in Wuhan, from where it mutated and became transmissible from person to person.

“From what we know, the source was the wild animals sold at the seafood market,” Gao told journalists on Wednesday.

“The virus of this wild animal is gradually mutating.”

The SARS-like #coronavirus is creating real life scenes like this. Stay safe out there my friends. 🙏😷 pic.twitter.com/uycbbsqget

— Jack Phan (@JackPhan) January 22, 2020

The SARS coronavirus is believed to have been transmitted by civet cats, a type of wild animal that is considered a delicacy in parts of China.

Authorities did not say what animal they suspected the new coronavirus came from.

Face masks were rapidly selling out in major Chinese cities on Wednesday, and authorities are asking people to avoid travelling to Wuhan – a city with an estimated population of some 11 million people – if possible.

The city on Tuesday said it had installed infrared thermometers at airports, railway and bus stations and was disinfecting public transport vehicles daily.

-with AAP