Avian flu concerns rise for Australia

Avian flu is devastating bird populations around the world and mutating into mammals with destructive consequences.

The most recent zoonotic virus caused three years of chaos, death and quarantine and scientists are recommending Australia develop a proactive strategy to avoid being caught by surprise.

Sydney University professor of virology Edward Holmes said "all the warning signs are there at the moment for avian flu".

"If there's something that keeps me awake at night - it's that," he said.

The likelihood of an animal-borne disease jumping to a human carrier is increasing with urbanisation creeping into natural habitats.

Invasive Species Council policy analyst Dr Carol Booth said avian flu had been mutating and exchanging genes between various strains "like crazy".

"There's been quite a few thousand deaths of mammals overseas but they've mainly been animals that eat birds," she said.

So there's "a question mark" over whether there's been any spread between mammals, Dr Booth said.

It wasn't known how avian flu would adapt in humans. It could spread quickly or it could be less virulent, Professor Holmes said.

The fatality rate was around 60 per cent for the 900 human infections globally since 2003, according to an article from the Doherty Institute and Deakin University.

Australia has no active cases of avian flu according to Wildlife Health's annual surveillance.

Avian, or bird, flu has circulated around the world for 20 years and Australia is the only continent, apart from Antarctica, that doesn't have cases, Dr Booth said.

The virus moves by the importation of poultry and the migration of ducks and other water birds, she said.

Australia's migratory birds have largely dodged avian flu while out of the country but they are susceptible, Dr Booth said.

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Doherty Institute researcher Dr Ash Porter said there are "many interwoven factors that contribute to the increased rate of zoonotic disease spill-overs we're seeing".

Climate change, urbanisation and land-use change is pushing humans and animals closer together, they said.

More interactions with animals increases the chance we'll spread our viruses to each other, Dr Porter said.

Professor Holmes said viruses moved between species regularly and most human viruses originated in animals.

Humans pass disease to animals as well. Humans are responsible for infecting 32 other animal species across 39 countries with COVID over 759 recorded incidents.

Doherty Institute scientist Dr Danielle Anderson said we should think about the health of humans as closely connected to the wellbeing of animals and our environment.

"As a virologist who works in the lab I don't necessarily know what's happening on a farm or in the planning of a new city development or a train line.

But all of those people should talk, she said.

"We should make sure people with different expertise end up, at some point, in the same room to think about big picture issues," she said.

Australia's "best bet" for avoiding another zoonotic pandemic is investing money and labour into sampling disease mutations in the wild, Dr Porter said.

Scientists could track COVID mutations through other mammal populations to better understand how the disease spreads, they said.

Dr Booth said Australia didn't have a plan for controlling avian flu in the wild but strategies were developed to stop the spread in poultry farms.

Australia successfully eradicated bird flu from chooks eight times and we did that by culling, she said.

"It's a pretty brutal response but it's very effective," she said.

But we can't do that for native fauna and the government has agreed to make a national wildlife response plan, Dr Booth said.

One method for controlling the spread of avian flu, used overseas, involved removing the bodies of dead birds from infected colonies, she said.

This limits the spread of disease to other birds and removed the risk of contaminating water sources, she said.

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