Contact tracers are scrambling to locate COVID-19 cases going undetected in the community as the Greater Brisbane lockdown ticks into its second day.

But infectious diseases expert Professor Nigel McMillan told Neil Breen while genomic sequencing can link some cases, contact tracers likely will never answer how the virus was passed between particular cases.

“We haven’t particularly physically linked the Stafford and the doctor case.

“There may potentially be another link in the chain.”

Professor McMillan said “thirty to forty per cent of people don’t have symptoms,” so many may never come forward for testing.

But Professor McMillan said he still expects numerous cases to be detected and announced today.

“I’d think that the lockdown would probably go for another couple of days beyond what we currently have.

“If the numbers are really high, then lockdown will probably change its purpose.”

Press PLAY below to hear the full interview

Image: Getty