Coronavirus: Three more cases of coronavirus confirmed in Australia

The number of confirmed coronavirus cases in Australia has risen to four nationwide after three cases were confirmed in New South Wales.

NSW Health says three infected men are being treated in isolation in Sydney's Westmead Hospital.

It comes just hours after authorities confirmed a case of the deadly coronavirus in Victoria. Australian authorities say a Chinese National in Melbourne was infected with the mystery illness that has so far killed at least 41 and infected nearly 1300.

About a dozen suspected cases of coronavirus are being investigated across Australia, Queensland's Chief Health Officer Dr Jeannette Young told media at a press conference on Saturday.

"It's an evolving number," she said.

"We will be treating them as if they're confirmed cases, as a precaution... we still don't understand the transmissibility of this virus."

So far, no New Zealanders are reported to have the illness.

"All travellers to New Zealand who become sick within a month of their arrival are encouraged to seek medical advice and contact Healthline at 0800 611 116 or a doctor and share their travel history," Ministry of Health director of public health, Dr Caroline McElnay, said on Saturday.

"It is important to mention recent travel from Wuhan and any known contact with someone with severe acute respiratory illness who has been in Wuhan. 

"As with all respiratory illnesses, people can take steps to reduce their risk of infection. This includes regularly washing hands, covering your mouth and nose when you sneeze, staying home if you are sick and avoiding close contact with anyone with cold or flu-like symptoms."

The World Health Organisation is yet to recommend any travel restrictions or border screenings, and New Zealand is yet to implement them. 

Some experts suggest the impact of thermal screenings would be minimal in detecting the illness. It can sometimes take days for symptoms to manifest and screening doesn't pin down the illness a person may have.

The new coronavirus can spread by human-to-human transmission. However, little is known about the illness. There is currently no vaccine for it. Officials are now trying to understand how efficiently the virus can spread to understand its potential threat.