The deadly H5N1 bird flu may have been detected in a migratory bird in Australia’s most populous state, which was previously free of the virus.

Five cases of the deadly avian influenza have been confirmed so far in seabirds in two states in Australia over the past week.

But a snap press conference called on Friday by NSW Agriculture Minister Tara Moriatry and the state’s chief veterinary officer Jo Coombe confirmed the virus may have reached a third state.

Samples from a giant petrel near Hawks Nest, a town about 228km north of Sydney, has tested positive for H5 influenza in preliminary testing at the department’s laboratory at the Elizabeth Macarthur Agricultural Institute.

“This latest development is incredibly concerning for both agriculture and for wildlife,” Moriaty told reporters.

“But NSW and the rest of the country have been preparing for this moment for many years.”

Surveillance and testing have been ramped up across NSW with the government working closely with industry to prevent a potentially catastrophic spread.

“The State Coordination Centre has been stood up in Orange, we have established the H5 bird flu call centre and we are briefing all key stakeholders on the current situation,” Coombe said.

“We are using the best available data now to target actions for our most at-risk wildlife species and important natural places.”

Until June, Australia had been the only continent free of the highly contagious virus.

The birds that have returned positive results for the strain since it was first detected on the Australian mainland on June 14 were a brown skua found in Esperance, WA, on June 14, a giant petrel on South Australia’s Fleurieu Peninsula on June 14,  a giant petrel in Esperance on June 18 and a giant petrel found at Roses-Quallup Beach at Esperance confirmed on Tuesday.

All positive cases have occurred in wild birds, with no signs the virus has spread to local poultry populations. There has also been no evidence of mass mortalities in wildlife.

While the virus can be deadly for animals, the risk to humans is generally considered low both in terms of transmission and health impact, Coombe said.

But a high number of deaths in wildlife and agricultural populations had been recorded in areas where the disease has run rampant overseas, she said.

“It’s had devastating impact overseas. There have been hundreds of species of birds affected, and also over 50 species of mammals.

“It can affect humans, but this particular strain is deemed to be very low risk to humans.”

Coombe said giant petrels generally migrate north from the southern ocean and don’t make landfall unless they are sick or have something wrong with them.

Moriarty said there were no reports of the poultry industry being impacted but producers had been informed of the new case and advised to increase biosecurity measures.

“I do want to be clear with the community, this is one bird, a wild migratory bird that has been found,” she said.

No mandatory enforcement measures have been imposed on industry.

“The government is working very closely with the poultry industry, and we have been for some time – they are ready for whatever scenario might emerge,” Moriarty said.

“There’s no need for panic buying eggs – keep buying eggs, keep buying chicken.”

People are being urged to avoid contact with sick or dead wildlife, report any finds to an emergency hotline, and record locations and take photos.

–AAP