"I have to say I am flabbergasted that a doctor that has flu-like symptoms has gone to work," the state's Health Minister Jenny Mikakos said.

"It is irresponsible for people to be going to work if they are unwell, and that is not just healthcare workers, it is everybody in the community who needs to take this very seriously."

People and patients who've been in contact with him have been ordered to self-isolate for two weeks.

"Patients have been contacted via text message this morning, or were called this morning, they will be followed up with emails," Mikakos said.

"This doctor also attended two patients at a nursing home in Malvern during that time. The two nursing home patients have been isolated in their rooms and the department is working to provide support care for these residents."

Authorities are also seeking the flight manifest so those on the man's plane can be contacted.

There are now at least 65 confirmed cases across Australia.