"There is very little more information at this stage. We have yet to receive genomic sequencing on which variant the case has or whether it is linked to other outbreaks."
Ms D'Ath said the student's family of five people, in the Brisbane suburb of Taringa, are being tested and contact tracers are working quickly to identify any further transmission.
She said authorities may take further action, once they establish the source of the infection.
"Because it is unknown or unlinked to other confirmed cases, masks are more important than ever, as well as social distancing and good hygiene."
Genomic sequencing expected to reveal more information
The acting executive principal of the school, Derek Weeks, said cleaners will deep clean the school as a precaution.
Queensland chief health officer Dr Jeanette Young said none of the recent outbreaks were connected to the school.
"I am struggling to understand how she acquired it," she said.
Dr Young said genomic sequencing results are expected later on Friday.
The CHO said the state had been responding to an increased number of COVID-19 cases in recent weeks.
"We do know that we have had 13 incursions of the virus into Queensland over the last six weeks," she said, urging people to get vaccinated.
"We know that in any particular outbreak, someone with can get infected, not have symptoms and then spread the virus to someone else, which is why it's critically important that we all remain very, very cautious until the vast majority of people have been able to be vaccinated."
In Queensland, 37 per cent of adults have received one dose, 17.1 per cent have received two doses. The number of vaccine doses administered in the state is 887,335.
Nationally, 17.7 per cent of people over the age of 16 have received two doses.
Positive case on flight from Brisbane to Perth
The list of Queensland's COVID-19 exposure sites has been expanded, as health authorities contact passengers who were exposed to a positive COVID-19 case on a flight from Brisbane to Perth last week.
Contact tracers are identifying passengers on board Qantas flight 932 from Brisbane to Perth on 20 July, and guests who were at the Brisbane City Backpackers HQ or Joe's Place Backpackers.
The passenger tested positive for the Alpha variant of COVID-19 on Monday, after he became unwell during his time in a backpackers hostel in Brisbane.
He had earlier been cleared to leave Brisbane hotel quarantine after returning three negative tests, following his arrival in the city on a flight from the Philippines via Papua New Guinea on 3 July.
He had attempted to to Perth on 17 or 18 July, but was denied entry into the state and forced to return to Brisbane on Qantas flight 932 to Brisbane on 20 July.
He stayed in WA hotel quarantine for a period before his return to Brisbane.
None of the other 62 guests at the hostels have tested positive, but they are being quarantined in their rooms.
People turned back at the border
Deputy Police Commissioner Steve Gollschewski said 4,076 vehicles had been intercepted at the state borders and 36 had been turned back on Thursday.
He said 633 domestic air passengers had arrived with eight denied entry and 170 put into home or hotel quarantine.
Mr Gollschewski said one person had been fined $1,378 after breaching home quarantine to visit their mother.
Meanwhile, 10 COVID-19 patients from a ship docked at Weipa, in the state's far north, have also been put into Brisbane hospitals for treatment.
Additional reporting: AAP