A new coronavirus case diagnosed in Queensland is connected to another announced two weeks ago, with the missing link between the pair likely still in the community.
Genomic testing on Friday confirmed the 26-year-old's case was linked to an infection announced on 12 March, which involved a doctor at the Princess Alexandra Hospital and two returned travellers.
He is confirmed to have the highly infectious UK mutant strain of the virus, known as the B117 variant.
Queensland Chief Health Officer Dr Jeannette Young said it is likely that an unidentified intermediary had passed the virus onto the Stafford man.
He tested positive on Thursday and visited at least nine different venues across the city after he became highly infectious last Friday.
The venues the man visited between Saturday and Thursday include Carindale Westfield, Gasworks at Newstead and Bunnings, Aldi and Guzman y Gomez at Stafford.
"We will know more in the next 24 hours, but in the meantime, those identified as visiting the locations in today's Public Health Alert should immediately get tested and isolate until you receive your results," Dr Young said in a statement on Friday night.
Health authorities are tracking down close contacts of the man, who will have to undergo quarantine.
Anyone who visited Mamma's Italian Restaurant at Redcliffe on March 21 between 12.40pm to 3.10pm will now be required to isolate for 14 days.
The infection sent Brisbane's hospitals into lockdown for the second time in a fortnight.
Aged care facilities, prisons and disability services are also shutting their doors for the next three days to stop the virus spreading to vulnerable people.
Everyone in the Brisbane City and Moreton Bay council areas are being urged to wear masks in crowded places and socially distance.
Premier Annastacia Palaszczuk said the man has been infectious in the community since last Friday.
She has ordered a lockdown of the city's hospitals, aged care facilities, prisons and disability services to prevent the virus spreading.
The focused lockdown will only cover the Brisbane City and Moreton Bay council areas and people are also being urged to wear masks and socially distance.
"We wanted to let the public know as soon as possible," Ms Palaszczuk told reporters.
"It is absolutely imperative over the next few days if you are sick and unwell to stay at home and go and get tested, it is absolutely critical that we do this over the next two to three days."
Chief Health Officer Jeannette Young said the man, who is being treated in Royal Brisbane and Women's Hospital.
His housemates are all self-isolating and getting tested in Stafford.
The man was working as a landscaper on 22 March when he started having symptoms.
"Anyone who's been to any of these venues during those specific time frames, I want you to come forward and get tested whether or not you've got symptoms, and to remain in isolation until you get a negative result," Dr Young said.
"Everyone else who is anywhere in Brisbane or Moreton Bay, it's really important, with any symptoms at all, please come forward to one of our many, many fever clinics and get yourself tested."
The man Aldi at Stafford on the day he was tested for COVID-19 and before he received his result.
Dr Young brushed off concerns he had not followed health advice, saying he had only "popped in" to the supermarket briefly.
The chief health officer said it was too early to know how many people the man had come into contact with, but contact tracers were working with the venues to track them down.
She said the person who spread the virus to him may also still be in the community while infectious.
The female doctor had worked a shift at the hospital and visited four venues in the city's south while infectious.
In response, the government locked down hospitals, aged care facilities, prisons and disability providers for seven days to avoid a wider outbreak.
That lockdown only ended last Friday.
Dr Young hopes the current case won't lead to wider restrictions on Brisbane because people now know how to respond to potential outbreaks.
"It just depends what unfolds over the next 24 to 48 hours, but we need to get used to living with these virus," she said.
"We're getting more and more people vaccinated, we've got great stats there, so as we get more people vaccinated the requirement to put restrictions in will diminish."
Queensland reported another six virus cases in hotel quarantine on Friday, taking the number of active cases 69.
The state has also administered 53,893 vaccine doses.
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