The Queensland government is investigating how a hospital worker who triggered the state's most extensive lockdown this year was not vaccinated against coronavirus.
The 19-year-old woman, who worked as a concierge at Brisbane's Prince Charles Hospital, tested positive on Monday after visiting a number of local venues and holidaying in the state's north last week.
It's since been confirmed she has the highly contagious Delta variant of COVID-19, which is twice as contagious as the original virus and can be spread through fleeting contact that lasts just seconds.
Her trip prompted the state government to lock down the state's greater southeast, Townsville, Magnetic Island and Palm Island for three days.
The woman's friend and two of her family members have become ill and are being tested.
She regularly worked at a desk outside the hospital's coronavirus ward where patients from hotel quarantine were being treated, but she wasn't vaccinated.
Premier Annastacia Palaszczuk has ordered an investigation into why that was the case.
"She should have been vaccinated, she was not. So the health minister will be overseeing that issue in detail," the premier told reporters.
"And let me say, I am absolutely furious about this. We need to make sure that we are getting a population vaccinated right across the state."
Under health orders only people working inside COVID-19 wards have to be vaccinated, but Ms Palaszczuk foreshadowed that that rule may need to be changed.
"There will be a full investigation into that, but let's just say this virus is contagious, it's hard to contain it in hotels, it's hard to contain it in hospitals, I mean, that's the truth of the matter," she added.
Chief Health Officer Jeannette Young said the woman developed symptoms on June 20 and had likely been infectious since June 18.
She visited a number of shops in the Sandgate area of Brisbane and worked at the hospital on Tuesday and Wednesday.
The worker then flew to Townsville with her family on Thursday, and visited numerous venues in the city and also travelled to Magnetic Island.
They flew home to Brisbane on Sunday.
Dr Young said all 2500 people living on the island must get tested for the virus.
News late on Tuesday that the worker has the Delta strain will heighten concerns among health authorities, given it is so infectious.
