A coronavirus patient who almost died from the disease says he is concerned there will be a second wave of cases across Australia due to a "complacency" about the threat posed by the novel pathogen.

Joseph Tannous spent two weeks in Sydney's St George Hospital's intensive care unit battling COVID-19-linked pneumonia.

Mr Tannous, who at the time of his infection was a fit and healthy 49-year-old, said the severity of his infection caught him off guard.

"Twice there my family was told I might not make it through," he said.

"The priest was called to pray for me, the last prayers, but I fought through and the great work of the hospital staff and the ICU staff at St George was fabulous."

"I am a fit and healthy person, I go to the gyms two or three times a week, I didn't expect the virus to have an impact on me ... but it is what it is, the virus doesn't discriminate."

The Founder of Cornerstone Group Australia told Sky News while he doesn't know how he contracted COVID-19, he got tested after attending a Liberal Party event on March 10th with Home Affairs Minister Peter Dutton, who later tested positive for the disease.

He said he is concerned the public has become complacent now that the COVID-19 curve has flattened.

"Obviously my view is there will be a second wave, as has been the case in Singapore and places like that," he said.

"I am noticing first hand people are becoming complacent ... I am noticing people have taken the view 'it is okay, we are over the worst of it' and the social distancing is out the door.

"I have to say social distancing is here to stay and the sooner we realise that the better it will be in saving lives."

There are just over 500 active cases of COVID-19 in Australia, while 6416 people have recovered and 100 have died.

Image: AP