The deadly H5N1 bird flu has reached a second Australian state, with a third seabird confirmed infected and more cases expected to grow on the mainland. But authorities say the risk of a human pandemic remains low.
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TRANSCRIPT:
The deadly H5N1 bird flu has reached a second Australian state, with a third seabird confirmed infected and more cases expected to grow on the mainland.
The third case was confirmed in a migratory sea bird in South Australia, after two earlier cases were detected in Western Australia.
All three were in wild sea birds, with a fourth suspected case also under review in Western Australia.
Head of the Kirby Institute Biosecurity Program at the University of New South Wales Professor Raina McIntyre says while Australia is well prepared for an outbreak, wild birds are difficult to control.
"I think Australia always has had very strong biosecurity and good preparedness. So I think we're very well prepared. It's the wild birds that's the factor that's difficult to control. We can control what happens on farms, you know, we can implement controls in the things that are within human control, like what we do with farms, cap trade of infected cattle or poultry, but the wild birds are more difficult to control, and that's how it's likely to spread that the wild birds will bring it in. So, that's the unknown."
The deadly strain has not been detected in the poultry or agriculture sector, with W-A Agriculture Minister Jackie Jarvis assuring the public there is no health risk eating chicken and eggs.
"There is no risk to human health from eating chicken or eggs from birds from Australia. That message will be conveyed by the Commonwealth in their normal trade discussions, but it is disappointing. But I can assure people of Western Australia to please keep eating your chicken and your eggs. There is absolutely no risk."
Australia, until recently, was the only continent without the deadly H-5-N-1 strain.
Professor McIntyre says while the current risk of a human pandemic is low, it could be higher than before.
"Risk of a human pandemic is judged by WHO and the US CDC as low, although the statistical probability is higher than ever because there's many, many more opportunities for humans and infected animals or birds to interact because it's just everywhere and there have been some mutations in the virus that do signal some kind of adaptation to mammals."
However, she says that pandemic planning in Australia is very well advanced and countermeasures are being developed.
"When the virus mutates, if the virus mutates, to switch affinity from the bird receptor to the human receptor. That's when we could see a pandemic. Pandemic planning is, you know, very well advanced in Australia and everywhere. Countermeasures are being developed. There are pre-pandemic vaccines and there are effective antivirals."
Around the world, other outbreaks of the strain has resulted in the deaths and culling of hundreds of millions of birds.
In turn, this has also led to major economic losses for farmers and concerns about the potential spread to mammals.
While the risk of spread to mammals is a concern, Professor McIntyre says animals like cattle don't get as sick from the disease.
When placed around poultry however, Professor McIntyre says pigs can be a risk.
"Yeah, we do worry about pigs because they're a genetic mixing vessel. You don't need humans contacting animals if a pig gets infected by a wild bird, the virus can mutate just within pig. So that's kind of a big concern. But historically, the H5N1 virus doesn't really like pigs. There has been an infection in the US that was but I think the risk is going to be where you've got poultry and pigs together. We've seen the case in the US was in a backyard farm where there were poultry and pigs."
In terms of wildlife, Dr Jane Younger from the University of Tasmania's Institute for Marine and Antarctic Studies says there is a big risk.
"We are seeing big mortality, particularly in seals and fur seals, to the point that Southern elephant seals have now had their conservation status changed as of April, so they've been… we've lost such large numbers of them in this outbreak that, the conservation status has been upgraded to vulnerable. So there is risk for Australian wildlife."
While vaccines for wildlife are being developed, Dr Younger says they're not available in Australia yet.
"The Marine Mammal Center in the United States is actually in the middle of trialling a vaccine for seals for this H5N1 strain. So they've been running this trial for about six months now. And so hopefully results of that might be available soon. It's tricky with vaccines. I mean, firstly, they're not approved for use in Australia, so that's the first hurdle. But most of them also require two separate injections, which, you know, for wild animals, of course, is really tricky."
Overall, experts say Australia has very strong biosecurity measures in place and is well prepared for a potential outbreak in humans, though the risk is considered low.
Professor Hugh Possingham from the Biodiversity Council of Australia says anyone who comes across a sick or dead bird should follow particular steps.
"Don't go and harass them. Don't pick them up. Don't let your four-year-old granddaughter chase them or dog. I've got a four-year-old granddaughter. She likes chasing birds. Try to avoid all those things, take pictures, record it, and report it immediately to the authorities."
