Contact tracing was also under way to determine the source and spread of the infection.

Agriculture Victoria said a 1.5-kilometre cordon and a larger buffer zone of 15 kilometres had been implemented near the Terang outbreak, which it says is linked to the Meredith farm.

The H7N3 strain of avian flu is different from the virulent strain of H5N1, which has been ripping through wildlife populations on every continent except Australia.

Fears the virus could evolve to pass between mammals were sparked earlier this year when cow herds in the US were infected and a dairy worker fell ill.

Sustained transmission of avian flu between humans has not yet been recorded.

Victoria’s Chief Veterinarian, Graeme Cooke, said the virus strain detected near Meredith was H7N3, as opposed to the H5N1 strain that has ravaged bird and mammal populations in the US and elsewhere.

“The current risk to the public remains low.”

Victoria’s Chief Veterinarian, Graeme Cooke

The deadly H5N1 variant was first detected in wild birds in Europe in 2020 and spread to birds in the US and Canada in late 2021.

More than 90 million birds and poultry have been infected with the H5N1 variant in the US since 2022, and it has killed thousands of Adelie penguins and skua seabirds in Antarctica. H5N1 has not yet been detected in birds in Australia.

“While cases among humans in direct contact with animals infected with highly pathogenic avian influenza viruses are possible, the current risk to the public remains low,” Cooke said.

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Federal Agriculture Minister Murray Watt said while it was a relief H5N1 had not been detected, Australia took any instance of highly pathogenic avian flu seriously.

“Australia has effective, nationally agreed response and cost-sharing arrangements in place to address animal disease incursions and outbreaks, and this has swung into action to support Victoria,” he said.

“Australia is well practised in responding to disease incidents in poultry and has successfully responded to eight outbreaks of HPAI [highly pathogenic avian influenza] in poultry since 1976.

“In all those cases, we were able to eradicate the disease successfully and rapidly with minimal spread between farms.”

In Western Australia, biosecurity measures have been tightened on a poultry farm in the state’s south-west after the discovery of an unrelated strain of avian flu.

Authorities say the strain detected in WA was a low pathogenic H9N2 strain and not connected to the Victorian outbreak.

On Wednesday, a child was confirmed as Australia’s first human case of the lethal H5N1 strain spreading around the world.

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The child, who returned to Victoria from India in March, experienced a severe infection after contracting the strain, but had made a full recovery, Victorian Chief Health Officer Clare Looker confirmed.

Authorities say contact tracing has not identified any further cases.

With AAP, Lachlan Abbott and Marta Pascual Juanola

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