Queenslanders are waiting anxiously to find out if efforts to stop the spread of coronavirus have been successful as the state counts down to another border closure.
It has been 16 days since two COVID-19-infected teens dodged quarantine and spent days moving about the community before police tracked them down.
Premier Annastacia Palaszczuk says there were no new cases diagnosed overnight but health officials remain on high alert following the breach.
"The next four days is still very crucial," she told reporters on Thursday.
"If you are sick, stay at home and get tested."
The premier urged people to be vigilant to stop the spread of the virus, saying "it only takes one or two cases for this virus to take hold".
Her plea comes hours after Health Minister Steven Miles said health officials didn't know how a 68-year-old woman falsely tested positive to the virus.
The Ipswich woman, who was the state's third locally acquired case in the past week, has since returned a negative result.
"She certainly tested positive on that first test and that's why we reported it," he told ABC radio.
"Subsequent tests came back negative and so we're just working through what's happened there."
Queensland will close its border with NSW and ban ACT residents from 1am on Saturday when Chief Health Officer Jeannette Young declares them coronavirus hotspots.
People returning to the state after that date will have to enter a 14-day hotel quarantine at their own expense.
The premier defended the decision to close the borders, saying health officials were concerned about the continued spread of the virus in southern states.
"We are in a world pandemic. It only takes one or two people coming into Queensland and we could have a situation like is unfolding in Victoria," she said.
"I do not want that to happen here."
She acknowledged that businesses would be hard-hit by the border closure, but said the impact on the state's economy of a second wave of coronavirus would be worse.
"It would be in excess of $4.8 billion," she said of the loss if the state was forced into lockdown.
Road access will be blocked to all vehicles once the border closes except those from border communities, with a list of exempt postcodes to be released in coming days.
The restriction on people travelling from Victoria remains in place.
People from non-hotspot locations will have to travel by air or via the Northern Territory border.
The decision to close the border will be reviewed at the end of August.
Australian Associated Press