One of the new cases is the manager of the Portuguese Family Centre, where the woman had visited, who has been in home quarantine before testing positive.

The other two were travelling with the flight attendant when she was out in Brisbane, and have been in hotel quarantine during their infectious period.

"I'm not concerned that any of these three cases are a risk to the Queensland community," Chief Health Officer Jeannette Young said on Thursday.

There have now been four cases linked to the flight attendant after a man who visited the family centre tested positive earlier this week.

Others who were at the centre - 36 in all - are continuing to isolate and are being monitored.

Dr Young said she was not concerned about the latest outbreak as all those believed to be at risk are in quarantine.

The flight attendant's positive result was confirmed by a routine test after she visited the family centre as well as the direct factory outlet at Brisbane Airport on Saturday.

It's believed she was infected by a hotel quarantine worker who escorted a COVID-positive guest to an ambulance and then went to the attendant's room to swab her.

Queensland's cases have all been the Alpha variant, which Dr Young said was "far less infectious" than the Delta variant circulating in Sydney.

"I strongly recommend that anyone in Queensland, unless you have an urgent unavoidable reason, this is not the time to go down into New South Wales," she said.

Queensland has now closed its borders to Greater Sydney and the surrounding regions of the Central Coast, Blue Mountains, Wollongong and Shellharbour in response to the growing outbreak.

Meanwhile plans are underway for a man who was in hotel quarantine in Sydney to be reunited with his dying father in Queensland.

A quarantine exemption issued on Wednesday evening to Mark Kilian and his partner Anneli Gericke was conditional on "NSW finalising arrangement of safe transfer of the couple to Queensland".

The have taken their final "exit" COVID test in NSW and, assuming a negative result, will be transported in full personal protective equipment to a charter plane due to leave for the Gold Coast around noon.

"It will be something I think we'll all remember for the rest of our lives," Mark told Nine Network on Thursday.

"We're not going on a holiday or a cruise, we're going for something that's going to be very sad, but at least there's a dignity to the way we can do it now."

Mark's father Frans Kilian, 80, is in hospital on the Gold Coast suffering from pancreatic cancer.

Mark and Anneli have been in Sydney completing quarantine after rushing to Australia from Los Angeles more than a week ago.

Both are vaccinated and have returned at least three negative coronavirus tests.

"We're not sure what the plan is when we arrive (on the Gold Coast) ... we're taking it one step at a time," Mark told Brisbane radio 4BC on Thursday.

"There are plans ... to facilitate a visit with my dad, we're just not sure when it's going to be."

Mark said his father was elated by the news.

"He was the first call we made and he was absolutely (as) elated and emotional as he could be in his state about the situation."

NSW Premier Gladys Berejiklian said on Wednesday her state had done everything it could to allow the reunion.

"At least a week ago ... New South Wales made it clear there was no impediment for them to make that journey."

The decision on the quarantine exemption for the couple came after Frans pleaded with Queensland Health to show compassion.

"Every day that they are in that hotel is a day less that I have with my son and daughter-in-law in my last days," he said in a video appeal from his hospital bed.

Australian Associated Press