Australia has recorded its first case of the more infectious UK strain of the coronavirus outside of quarantining returned overseas travellers.
A cleaner at a Brisbane quarantine hotel has been diagnosed with the UK variant, sending aged care homes across greater Brisbane into lockdown.
Visitors will be barred from visiting facilities in the Metro North, Metro South and West Morton heath regions.
Hospitals, prisons and disability accommodation in the same areas are also banned from accepting visitors.
"The Chief Health Officer has ordered these immediate steps to protect vulnerable members of the community," Premier Annastacia Palaszczuk tweeted on Thursday night.
The state is on high alert for cases of community transmission after the cleaner tested positive on Thursday.
The mutated strain plaguing the UK is believed to be up to 70 per cent more infectious than the original.
It is causing a sharp rise in cases in England and prompted British Prime Minister Boris Johnson to order a national lockdown until at least mid-February.
Britain reported more than 60,000 new confirmed cases in 24 hours for the second day in a row on Wednesday.
The hotel cleaner's infection ends almost four months of zero locally acquired cases in Queensland.
"Queensland has done a great job containing this virus in our community for 113 days. Sadly, today we do have a locally acquired case," Health Minister Yvette D'Ath said on Thursday morning.
The positive case, a woman in her 20s, was infectious from January 2 before testing positive after showing symptoms on Wednesday.
Anyone with symptoms of coronavirus is urged to get tested immediately.
Contact tracers are tracking the movements of the cleaner, who worked at the hotel Grand Chancellor on January 2.
"This cleaner did everything right," Ms Palaszczuk said earlier on Thursday.
"She developed the symptoms Wednesday and was tested yesterday.
"We need to ensure that there is no community spread. Once again, please, if you're sick, get tested."
The woman from Algester travelled on the public rail network to and from Brisbane's inner city and southside.
Health authorities say she visited several locations while potentially infectious.
The woman travelled on a train from Altandi station to Roma Street station at 7am on January 2, then returned on the 4pm service the same day.
She also visited Woolworths at the Calamvale Central Shopping Centre from 11am to 12pm on Sunday 3 January.
She was also at Coles in Sunnybank Hills for 30 minutes from 7.30am on Tuesday 5 January.
She was also a newsagent at Sunnybank Hills Shopping Town from 8am to 8.15am on the same day.
"It's important that people if they have any symptoms at all come forward and get tested," Chief Health Officer Jeannette Young said.
Residents of Algester, Sunnybank Hills and Calamvale who have symptoms of the infection are especially urged to get tested as soon as possible.
The Sunshine State now has 20 active COVID-19 cases and the new positive case comes from 15,000 tests over the previous 24-hour period.
Ms Palaszczuk has also announced travellers coming from Greater Sydney will not be allowed into Queensland until at least the end of January.
"I know this is very disappointing for people during this time, but we are concerned still about Greater Sydney. We have a watching brief as well on Victoria," she said.
"We'll be having a national cabinet meeting tomorrow. I'll get further updates there."
The border closure will be reviewed at the end of the month.
Australian Associated Press