Queensland has recorded just two new locally acquired cases of Covid-19 in what state premier Annastacia Palaszczuk described as "very encouraging" news.
One is a close contact of a case linked to a Portuguese restaurant and has been in hotel quarantine for their entire infectious period.
The other is a 37-year-old woman who worked at the Qatar check-in counter at the Brisbane international airport.
After becoming unwell and displaying symptoms, she was tested on Tuesday and returned a positive result.
"She has been to very limited places around her local area," Ms Palaszczuk told reporters on Thursday.
But health authorities warned she would have mingled with customers and flight crew.
"She works at the check-in counter the Qatar airlines which means she would be checking in not only the passengers, but she would be involved with the crew," the state's chief health officer Dr Jeannette Young said.
“I really and truly insist people must wear masks at the international airport and at our domestic airports, that is really critical. You don't know you might be infectious as you are walking around that airport.
“This lady in her 30s became symptomatic on the 27 June, so that means her infectious period goes back to last Friday. We are speaking to her at the moment to get all of her contact tracing achieved,” Dr Young said.
She attended Officeworks on June 25, Coles on June 27 and Anytime Fitness, but authorities are still working to determine the precise time windows.
Dr Young added that testing indicated the airport worker was likely not shedding much virus.
No word if lockdown will end on Friday
Presenting an optimistic front, the premier said it was too early to confirm if the lockdown will still end on Friday night
"We're not out of the woods yet," Ms Palaszczuk said.
"We've got another 24 hours to see what happens ... in relation to whether or not we can lift the lockdown, but it is very encouraging news at this stage."
A partial lockdown covers residents of Brisbane, Ipswich, Logan City, Moreton Bay, Redlands, Sunshine Coast, Noosa, Somerset, Lockyer Valley, the Scenic Rim, the Gold Coast, Townsville, Magnetic Island and nearby Palm Island.
Despite long waiting times, Queensland carried out nearly 30,000 tests in the past 24-hour period.
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