A Sydney university student who had been living in campus accommodation has been confirmed as the fourth case of coronavirus in Sydney.

The 21-year-old woman returned from Wuhan, China — the epicentre of the deadly virus — last week and developed symptoms within 24 hours.

She presented to the Emergency Department and is now being treated at Westmead Hospital in Sydney's west.

In a statement, the University of NSW said the student had no close contact with others in the Kensington student housing, in Sydney's south-east.

"The student adhered to advice and precautions since arriving from Wuhan on January 22... [she] did not attend any classes at the university and stayed on her own in campus accommodation," the university said.

"NSW Health has stated the student was not infectious on the plane."

The latest case brings the number of confirmed cases in Australia to five.

© Provided by ABC Health The 21-year-old woman who contracted coronavirus arrives at Westmead Hospital. (ABC News) NSW Health said the woman had no high-risk contact with other people once back in Sydney.

"There are just a couple of low-level contacts we are currently tracing," NSW chief health officer Kerry Chant said.

Eighty people are now dead worldwide as the virus continues to spread, with 2,744 confirmed cases.

All flights from China into Australia will now be met by border security officers to ensure unwell passengers are identified and health warnings are delivered.NSW is investigating six other potential cases while Western Australia is waiting on results for four patients.

However Australia's chief medical officer Professor Brendon Murphy said he did not believe the risk was high enough to quarantine thousands of passengers on arrival.

"I'm not aware of any first world country that is doing that ... we think the risk of someone coming on current flights is very low," he said.

A combined population of 25 million people across eight cities in China's Hubei province have been put into lockdown to contain the spread of the virus.

Despite conflicting reports, all available evidence suggests the virus is only infectious after the onset of symptoms, Dr Chant said.

NSW Health Minister Brad Hazzard stressed that visitors from China with symptoms could present to any public hospital in the state at no cost.

"If you don't have travel insurance, you won't need it, because we're making sure that the tab will be picked up by the Government," he said.

Students urged to receive all-clear before returning

Three Sydney schools, The Scots College, Kambala School and Newington College today contacted parents warning students whose families had been to China would need a doctor's certificate before term one.

The NSW Department of Education encouraged principals to "monitor children and staff closely for any strange illnesses".

Mr Hazzard said it would "generally be quite safe" to attend school and universities but those with symptoms should stay in isolation and get medical advice.

"[But] I'd remind everybody that to this moment there has been no infection between humans in Australia ... these people who have actually been infected have had that occur in China or possibly on a flight from China," he said.

In an email to parents, The Scots College revealed it had received "several enquiries" about coronavirus.

"If your family has recently visited China, we ask that you refrain from sending your son/s to school until they have received a medical clearance from a doctor," the email read.

It said students who had been to China must "visit the College Clinic immediately for a preliminary check-up" before commencing the school term.

"The Scots College Parents' Association Cocktail Party will still go ahead on Tuesday 28 January, though if you have visited China during the holidays, we ask that you do not join us this year," the email continued.

The college also cancelled the Chinese New Year celebrations scheduled for January 31 "as a precautionary measure".

In Melbourne, the Xin Jin Shan Chinese Language and Culture School has postponed the start of the school year due to parents' concerns and independent school Haileybury has asked students, parents and staff who have been in China to self-quarantine for 14 days.

At the weekend, Professor Murphy said the general public should not be alarmed.

"There is no risk to Australian population other than people with that travel history or who have been in contact with those people," he said.

