However, Twinnies Pelican and SeaBird Rescue has complained that confusion surrounds the handling of sick birds in Queensland as another case was identified.
Australia has 14 cases after a "presumed positive" was detected in a petrel in Western Australia, authorities confirmed on Wednesday.
There were fears the strain had spread to Queensland after a sick northern giant petrel was taken to the Twinnies facility, a registered charity managed by identical twins Paula and Bridgette Powers.
Testing confirmed the petrel was not infected with the highly pathogenic strain, the state's Department of Primary Industries has confirmed.
''There was a lot of worry, but Twinnies are very, very relieved,'' the twins' mother Helen Powers told AAP.
The welcome news comes as the Twinnies press ahead with the expansion of its on-site quarantine facility, anticipating more sick seabirds as the virus continued to spread elsewhere.
The petrel found at Lancelin Beach, WA was being treated as a positive as a precautionary measure after the sequencing of the virus could not be determined, authorities said.
A total of 14 cases have been found across WA, South Australia and NSW.
"All but one have been wild migratory seabirds," Australian Chief Veterinary Officer Beth Cookson said in a statement.
"There remains no evidence of any mass mortality events and there are no detections in poultry or in our agricultural production system.
"The risk to human health remains low."
As the case numbers rose, Ms Powers said there was still confusion in Queensland about who should handle sick or dead seabirds and where they should go.
People have been told to call a biosecurity hotline, but Ms Powers said that often resulted in birds being directed to Twinnies because the Sunshine Coast facility was one of the few places equipped to take seabirds and migratory species.
She had been told some coastal staff were advised to simply dispose of birds.
''We were told yesterday they said to just put the birds in the bin,'' she said.
''I don't get it - they need to get their facts right and tell people clearly what to do.''
Other wildlife centres had stopped taking certain seabirds, leaving Twinnies as a de facto frontline facility.
''At one stage we were told Australia Zoo wasn't taking any in ... RSPCA weren't taking them - and the birds come to the Twinnies because they've got a quarantine room,'' she said.
Ms Powers said in other states government and wildlife agencies had been running detailed preparation sessions and joint responses.
While noting Queensland RSPCA's Wacol centre was planning an information session on July 20, she said that was a "bit late".
However, Biosecurity Queensland said the state was "well prepared for H5 bird flu".
"Biosecurity Queensland is collaborating with Queensland government agencies including Queensland Health and the Department of the Environment, Tourism, Science and Innovation to ensure robust preparedness and response arrangements are in place," it said in a statement.
Anyone concerned about a sick or dead bird or wildlife should avoid contact the Emergency Animal Disease Hotline on 1800 675 888 (24/7).
13°C