Poultry farmers are being urged to temporarily shelter free-range hens as authorities confront a rising bird flu threat.
The alarm was raised when a suspected case of the deadly H5N1 strain was found in a migratory bird in New South Wales, signaling that the virus may have reached the east coast. Previously, five cases had already been confirmed in Western Australia and South Australia.
Adding to the concerns, another potential case cropped up on Friday in a migratory bird located in Mullaloo, a northern suburb of Perth.
Given these developments, Australia’s technical body responsible for animal health emergencies has recommended that commercial poultry producers consider keeping free-range birds inside temporarily. This precaution is advised for the forthcoming two weeks while the extent of the biosecurity threat is evaluated.
Sam Hamilton, acting chair of the Consultative Committee on Emergency Animal Diseases, emphasized that farmers should ensure that any measures to house hens indoors are practical and do not compromise animal welfare.
Dr Hamilton, Australia’s acting chief veterinary officer, said it would be up to states and territories to endorse the body’s non-mandatory recommendation.
“There have only been detections in migratory seabirds that occasionally visit Australia,” he said after the emergency animal diseases committee met on Friday.
“There remains no evidence of any mass mortality events and there are no detections in poultry or in our agricultural production system.
“The risk to human health remains low.”
Careful surveillance and testing crucial
Burnet Institute scientific director for research translation Heidi Drummer said the suspected case in Hawks Nest, on the NSW Mid-North Coast, was significant, but there was no reason to panic.
“Avian influenza viruses do not easily infect people, and human infections usually occur after close contact with infected birds, infected animals or heavily contaminated environments.”
Drummer said careful surveillance and testing were crucial as authorities tried to determine whether the detections in migratory seabirds were isolated events or part of a broader pattern of virus movement in wild bird populations.
“It is important to be clear that detection in wild birds does not mean the virus is widespread in Australia, or that it has entered commercial poultry,” she said.
“Detecting the virus early gives authorities the best chance to understand where it is, limit spread where possible, and protect poultry, wildlife and people.”
The strain was first detected on the Australian mainland on 14 June in a brown skua found in Esperance, on Western Australia’s south coast.
More substantial testing is expected to confirm the NSW case over the weekend.
Australia’s response ‘very good’, expert says
Emma Grant, from La Trobe University’s Institute for Molecular Science, said the virus could spread very quickly.
“It can also be quite severe in different animals, so what it means for the wildlife in Australia is yet to be seen,” Grant said.
“That’s certainly been the talk from a lot of experts in the field, that we don’t know what is going to happen to our native bird populations.”
The public has been urged to avoid contact with sick or dead wildlife, report any finds to an emergency hotline, record locations and take photos.
The spread among migratory birds was “largely inevitable” but Australia was still doing “a very good job” of containing bird flu, Mater Health Services director of infectious diseases Paul Griffin said.
“While we are talking about three states and still a very small number of cases, it highlights how we have to remain vigilant and make sure that we protect the poultry industry and other bird populations,” Griffin said.
All positive cases had occurred in wild birds, with no signs the virus had spread to local poultry populations.
It was now “only a matter of time” before further cases were detected in other states, and the impact on commercial bird populations could be devastating if large-scale culls were required, Griffin said.
“But we do have good protocols in place … some of the largest producers have implemented more stringent measures to reduce that risk,” he said.