Queensland is dealing with two new outbreaks of the highly contagious Delta strain and will close its border to people from Victoria to avoid importing any more cases.
From 1am on Saturday, anyone arriving from Victoria faces a mandatory fortnight of quarantine, as the southern state's outbreak continues to grow.
Premier Annastacia Palaszczuk said she had no choice but to list Victoria as a hotspot alongside greater Sydney, which are both in lockdown.
She told Queenslanders: "Do not go to NSW, do not go to Victoria during this period."
Chief Health Officer Jeannette Young says Queensland is currently dealing with two new outbreaks of the highly infectious Delta strain of the virus.
One involves a 12-year-old boy and his parents whose infections have been traced back to hotel quarantine in Sydney.
The boy and his father were among three cases reported on Thursday. His mother was the sole local case reported on Friday.
Dr Young says genomic sequencing has shown the boy has the virus that's spreading in Sydney.
He and his mother, who'd been overseas, completed hotel quarantine in Sydney before flying home to Brisbane.
"It's confirmed, very tightly confirmed, with that outbreak that's going on in the community down there in Sydney," Dr Young said.
"The people in Sydney, the health staff there, will be working through how he acquired the infection while he was in hotel quarantine down there."
But mystery surrounds the source of the third infection reported on Thursday - a woman who works as a supervisor at one of the boarding gates at Brisbane International Airport.
Dr Young said the woman's infection is genomically different to an earlier case involving another airport worker in Brisbane.
"So that means there hasn't been direct transmission from that previous worker at the airport to this worker at the airport," she said.
"There has been some other transmission that has occurred at the airport. We will have another look if we can find any other close matches but at this stage we can't find any close whole-genome sequence matches.
"I'm quite convinced that we have today in Queensland two new outbreaks, they are not related to all of the other outbreaks that we were dealing with."
Contact tracers have so far identified 62 contacts of the family, and 45 contacts of the airport supervisor.They are isolating and being watched closely.
Deputy Police Commissioner Steve Gollschewski said people are continuing to come into Queensland on false declarations.
One case involves a limousine driver and three passengers who've been put into quarantine.
"The three passengers aren't cooperating at the moment so further investigations are ongoing and the driver has been fined $4,135 for a false declaration," he said.
New added causal contact tracing sites as of Friday 16 July:
MONDAY 12 JULY:
*Redcliffe GP Super Clinic Pharmacy - 9.39AM - 9.45AM
*Redcliffe GP Super Clinic Pharmacy - 9.52am - 9.55am
*BP Caboolture North Bound, Caboolutre 7.50am - 8.10am
TUESDAY 13 JULY:
*Flannerys Organic Health Food Store, Chermside 4pm - 4.20pm
*Your solution Compound Pharmacy, Aspley 4.45pm - 4.55pm
*Woolworths, Kippa-Ring 6.45pm - 7pm
Australian Associated Press