By Ben Cubby
Avian influenza has been detected at another farm in the Hawkesbury region, in Sydney’s north-west, indicating it has spread beyond a poultry farm quarantined by authorities last week.
The second infected farm is within a 1.5 kilometre biosecurity zone declared after the virus was detected on a commercial egg farm on Wednesday.
The CSIRO’s Australian Centre for Disease Preparedness confirmed the presence of High Pathogenic Avian Influenza H7N8 at the two sites - a different strain of the virus than that found in seven egg farms in Victoria.
It is a separate virus to the H5N1 that has spread rapidly among wild birds around the world and has been transferred to other animals including humans.
The disease, which spreads quickly and has a high mortality rate among chickens, was probably introduced to the NSW chickens by wild birds, experts said.
Wild birds, such as migratory ducks and geese, carry about 140 different types of the virus and can infect chickens and ducks on farms as they pass by.
After a series of separate events in Victoria, Western Australia and now NSW, experts said seasonal conditions might be pushing wild and domestic birds into closer proximity.
“The biosecurity plan is working and because teams responded rapidly, we have been able to quickly survey, test and detect another site, that had been locked down on Wednesday 19 June,” the NSW Minister for Agriculture Tara Moriarty said in a statement.
“This type of avian influenza is highly infectious in commercial poultry and it was always a possibility that we could detect sites within the control zone. The government will continue its testing at sites.”
About 87,000 birds at the farms are being culled, a process expected to take at least three more days.
Eggs and poultry meat are safe to eat, the government said.
The last bird flu outbreak in NSW was in 2013, when it was eliminated by bird culls and exclusion zones.