The flight attendant, aged in her 30s, arrived in Brisbane on an Emirates flight on June 5 and tested positive after being released from hotel quarantine.

The state's chief health officer Dr Jeannette Young says she is "very concerned" because a passenger on that flight tested positive for the highly infectious Delta variant.

"I am treating this case as if she does have the Delta variant," Dr Young told reporters on Sunday.

Tests have not confirmed that the woman has contracted the Delta variant.

The state government has listed exposure sites including Brisbane's airport DFO and a Portugese family centre.

Dr Young said the new case left hotel quarantine at 9am on Saturday and went by shuttle bus to the Hamilton apartments before visiting airport DFO at 4pm Saturday.

Anyone who was at airport DFO between 4pm and 4.30pm Saturday is being told to isolate immediately and notify Queensland Health.

The case was also outside in the city between 5pm and 6pm, and anyone in the CBD at that time is being told to monitor for symptoms.

She then visited a Portugese centre at Ellen Grove between 7pm and 7.50pm.

"We do need everyone who has been to these sites to immediately isolate themselves," Premier Annastacia Palaszczuk said.

At the same time, Queensland is easing virus restrictions, including density measures that will see more people allowed to go to restaurants, cafes and bars, with three people allowed per four square metres.

The measures will ease from Friday and will also mean more people are allowed on reef charter boats.

There will be no virus restrictions on visits to aged care homes and hospitals.

Ms Palaszczuk urged people to check in to any venue they visit using the app.

"It's not too much to ask for more freedom, we want life to go back to as normal as possible," she said.

Australian Associated Press