Bird flu alert: Avian influenza risk upgraded to high

Australia's chief vet has upgraded the risk of highly pathogenic avian flu infecting Australian birds to “high”.

Avian veterinarians like Peter Scott say the risk of highly pathogenic H5N1 influenza clade 2.3.4.4b entering Australia via wild birds has been raised to high.

Free range poultry production is set to grind to a halt across large parts of Australia once the high pathogenicity form of avian influenza H5N1 clade 2.3.4.4b reaches our shores.

Most avian veterinary experts say it’s not a case of if but when the HPAI clade hits Australia and New Zealand, given surveys are picking up the virus in dead seabirds on the Antarctic Peninsula.

Australia’s chief veterinary officer and Department of Agriculture, Fisheries and Forestry have recently updated their assessment to state “there is a high risk associated with HPAI H5N1 clade 2.3.4.4b incursions and establishment into Australia for wild birds” and a “moderate/high risk for poultry”.

The risk assessment of infections spreading to wild Australian mammals remains low, but with “a high degree of uncertainty”, given the HPAI clade has emerged in the sub-Antarctic, where thousands of wild birds and marine mammals have been infected.

Avian veterinary specialist Peter Scott, who advises the government on the risk to poultry, said that while the host range and risk had risen, the way Australia responds to outbreaks remained the same, but with enhanced awareness of the involvement of clade 2.3.4.4b.

“Nothing has changed,” Dr Scott said. “(Under) the AusvetPlan its slaughter and eradication.”

Dr Scott said housing orders would also be issued as outbreaks occurred, requiring all free-range poultry within a declared region indoors – commercial and backyard birds.

Just how far the housing order extended would depend on the species involved in any outbreak, plus the degree and rate of spread.

Overseas experience shows the HPAI clade 2.3.4.4b, which emerged in 2020, quickly spread across Europe and via bird migration routes to the Americas, killing 500 million birds and infecting at least 26 mammalian species.

Just last week one of the US’s largest egg producers Cal-Maine Foods was forced to slaughter and eradicate 1.6 million laying hens and 337,000 pullets infected with the virus.

The spread of the HPAI clade in Australia will depend on which species it infects.

If the virus was identified in sea gulls or skuas, then Dr Scott said housing orders may be extended across peri-urban areas or if it was found in pelicans and other bird species that move to regions within Australia then it may extend much further.

In the European Union and UK, housing orders were imposed for months, forcing free-range egg and chickenmeat producers to abandon labelling their product free range.

Widespread outbreaks in Australia, resulting in extended housing orders are also likely to force free range eggs off the shelf, crippling Australian supermarkets giants Coles’ and Woolworths’ bids to end caged-egg sales by next year.

Egg Farmers of Australia chief executive Melinda Hashimoto was asked what strategies the group had to deal with the impacts of a widespread HPAI clade 2.3.4.4b outbreak and the impacts of extended housing orders.

But Ms Hashimoto responded by simply stating “there is no avian influenza in Australia at present”.

Industry marketing body Australian Eggs said it was “not well placed to provide a response to your question as we are not the authority on labelling” during an extended housing order.

The Australian Competition and Consumer Commission has previously imposes hefty penalties on egg producers who make false or misleading representations that their eggs are free range.

Ongoing surveillance of wild birds, supported and funded by the federal government, has not yet identified H5N1 clade 2.3.4.4b in Australia.