Millions of birds have died from a new strain of avian flu sweeping the globe and while it has not been detected in Australia yet, experts are worried the virus also has been detected in mammals.
The new H5N1 avian influenza strain has ripped through birds across every continent except for Australia and Antarctica, killing hundreds of millions of wild and farmed birds globally in the past year.
This week authorities confirmed four dead seals in Scotland died last year of the highly pathogenic avian influenza (HPAI), and so far about 70 other mammals including otters and foxes have tested positive for the strain of the virus.
New research has revealed migratory birds could transport the virus to Australia, with wider worries the virus could be transmitted to humans.
In 2020 and 2021 six Victorian farms, including an emu farm, were forced to cull almost half a million birds after multiple outbreaks of bird flu involving three different strains of the virus.
Avian flu variant 'needs tighter biosecurity'
Deakin University chair of ecology Marcel Klaassen said the new foreign variant was highly pathogenic and a potential threat to Australia, and more monitoring was needed.
"You should think about it the same way as with COVID-19. Coronaviruses are omnipresent but certain strains can cause a problem," Professor Klaassen said.
A Deakin University study reviewed more than 10,000 birds over the past decade and found waterfowl and shorebirds were common carriers of avian influenza virus, but it could be passed on to other bird species as well.
Professor Klaassen warned millions of shorebirds migrated between Australia and Asia and "they could form the bridge for this virus to come to Australia".
"We really have to be on guard," he said.
Professor Klaassen said stopping bird migration was not possible, but additional biosecurity measures should be implemented to prevent the virus from infecting the poultry industry.
He said 70 per cent of global bird population was farmed poultry, "and they are ultimately the ones that keep the nasty viruses going".
"So we should be on the ball to monitor our wildlife."
The federal Department of Agriculture's website states "eggs, meat and poultry products in Australia are safe to eat".
"Ongoing outbreaks of H5N1 globally have increased our level of risk for incursions of HPAI viruses of global concern," the website states.
"Migratory birds returning to our shores annually between September and November may introduce HPAI viruses."
Virus can move between animals and humans
Professor Klaassen said the virus was a zoonotic disease, meaning it could be transmitted between species from different animals to humans.
"There are already a lot of cases where it has jumped from birds to seals, minks, foxes, all kinds of animals, and unfortunately there are also people that become infected," he said.
While he stressed there was currently no threat to Australia, he urged authorities to monitor birds entering Australia when the next migration season started in September.
A federal Department of Agriculture, Fisheries and Forestry spokesperson said the department was "closely monitoring the evolving international situation", but said the risk of HPAI viruses being introduced to Australia was low.
The department has a national wild bird surveillance program that collects samples from "wild birds, including waterfowl and shorebird species, at targeted sites such as wetlands and tested for avian influenza viruses".
It also monitors commercial poultry flocks.
The department spokesperson said to date "thousands of Australian wild bird samples have been tested with no high pathogenic strains of avian influenza detected in our wild birds".
"A recent study has also confirmed that there continues to be no evidence of HPAI in inbound migratory birds at the end of 2022.
"Australia is well prepared to respond to an avian influenza outbreak," the spokesperson said.
Low risk but vigilance is needed, chief vet says
Victoria's chief veterinarian Graeme Cooke managed the 2020-2021 avian flu outbreak in that state, which was Australia's largest-ever breakout.
He said the current strain in the northern hemisphere was particularly troubling because "normally it would be seasonal, and it is now showing it can persist throughout the entire year".
However, he said Australia was not on the path of major migratory birds so the risk to Australia was low.
But he warned poultry farmers to be vigilant.
"It's always important for poultry farmers to have good levels of biosecurity to keep their birds separate from wild birds where possible," Dr Cooke said.
"For example don't let them feed from the same source as the wild animals."
