November 15, 2012.
A new unidentified strain of bird flu has been detected at a hen farm near Maitland in the Australian Hunter Valley, prompting authorities to quarantine about 50,000 chickens.
The suspected virus is not thought to be the deadly H5N1 strain of bird flu that has killed 359 people worldwide in sporadic outbreaks since 2003.
Nonetheless, the 50,000 hens may have to be destroyed, the NSW Department of Primary Industries said.
A "first response team" of specialists from the department is on site to enforce the quarantine, while the CSIRO runs lab tests on samples of the virus, with results expected this afternoon.
"The suspected virus is definitely not the highly pathogenic H5N1 strain that has gained worldwide attention — nor is it closely related to that strain," the NSW chief veterinary officer, Ian Roth, said in a statement.
"Australia has previously had a small number of outbreaks of avian influenza viruses, which were all quickly and successfully eradicated," Dr Roth said.
"The property has been placed under quarantine and initial tracing and surveillance is being undertaken to confirm that the virus hasn't spread. We currently have no evidence to suggest it has."
The department said Australia has had five outbreaks of avian influenza in chickens between 1976 and 1997 – three in Victoria and one each in NSW and Queensland.
"All the outbreaks were contained and successfully eradicated with no impact on human health," it said. "They were not caused by the H5N1 strain. They were all from an H7 strain."
The property owners are cooperating with the department over today's apparent outbreak, and the Egg Corporation had been informed, the department said.
The NSW Food Authority's latest advice on bird flu, issued on Wednesday, said that the virus does not pose a risk to humans in Australia, but that it was monitoring developments.
"Our usual advice remains to not eat raw eggs, cracked or dirty eggs and to cook poultry thoroughly," the authority advised. "There has been no case reported of humans getting infected from eating food ... The latest scientific evidence shows the virus responsible for bird flu is killed through careful cooking: it is destroyed at temperatures above 70C."
The H5N1 strain of the virus can be transmitted from birds to humans, and scientists fear it could mutate and cause a major pandemic by jumping from person to person.
Other versions of the strain cannot be transmitted to humans, or transferred from human to human at the present time.
Containing the virus is the subject of ongoing research in many countries. In Australia, CSIRO scientists are experimenting with "gene silencing" in an attempt to make chickens immune to the virus.
Two controversial scientific papers were published in June, describing the nature of the H5N1 virus, amid fears they could be used to modify the virus by mutation and turn it into a weapon.