The risk of a COVID-19 outbreak in Queensland is escalating after another 20 cases were recorded in the state, the chief health officer warns.
One of the new cases recorded on Wednesday was a man who has been infectious in Brisbane for six days, while another 19 people with coronavirus are contained on a ship offshore.
The man who was infectious in Brisbane completed hotel quarantine on July 17 then stayed at a backpacker hotel before becoming unwell and getting tested on Monday.
Chief Health Officer Jeannette Young says the man has likely been infectious since last Thursday and contact tracing is underway.
"I think this is escalating now, we have had 13 incursions of the virus into the community...over the last six weeks," she told reporters.
"That is more than we've seen before for a long time, so I'm very worried."
Late on Wednesday, Queensland Health said all people in Joe's Place Backpackers and Brisbane City Backpackers from the afternoon of July 20 to 1am July 28 were close contacts.
Anyone at Brisbane Domestic Airport about 1.30pm on July 20 or the emergency department of the Royal Brisbane and Women's Hospital about 10pm on July 26 are low-risk contacts and should get tested.
Dr Young is also expecting genomic sequencing to reveal exactly where a Gold Coast man, who tested positive earlier this week, caught the virus.
It's believed he caught the Delta strain from another hotel guest staying in the room opposite him at the Amora Hotel in Brisbane.
The hotel quarantine system was "clearly insufficient" in containing the Delta variant of COVID-19, Dr Young said.
She said the state's proposal for a quarantine facility at Wellcamp, near Toowoomba, should be reconsidered by the federal government.
The chief health officer has also ordered state and federal politicians be prioritised for vaccination due to the risk of them bringing the virus into the regions.
"We know that as part of their role politicians meet all sorts of people," she said.
"So I'm just concerned there, it's quite a small group, but I would like them all to be vaccinated as soon as possible."
The prioritisation comes as Queensland Health confirms six people were given an "ultra low" dose of the Pfizer vaccine at Rockhampton Hospital.
While the error has not caused harm to those affected, it means 159 people have been offered another vaccine because authorities aren't sure which patients got the low dose.
"To ensure full vaccination of all 159 people, everyone who received a vaccination that day will be offered a new appointment to receive a repeat dose," Dr Young said.
"It essentially means these people will be getting an early booster shot of Pfizer."
Of the 159 people, 55 were scheduled for a first dose and 104 for their second.
The "most plausible" explanation for the error was a vial of the vaccine, which contains six doses, being diluted with saline a second time because it was not disposed of once prepared.
Meanwhile, authorities recorded another 19 COVID-19 cases on a ship off the coast in the far north.
Dr Young said the bulk carrier Sanyo was due to arrive in Weipa on Wednesday.
Queensland Health will transfer the sick crew members, most of whom are from the Philippines, to hospitals in Brisbane.
Quarantine requirements will also be relaxed for Queenslanders and people with travel exemptions in Victoria and South Australia after both states lifted their lockdowns overnight.
Permitted travellers will be allowed to quarantine at home, rather than in government hotels, from 1am on Friday.
Australian Associated Press