Australia’s chooks could be at risk from highly infectious strains of bird flu circulating the country.
Three separate H7 strains of avian influenza have been detected so far. Biosecurity-restricted zones have been set up around the farms to prevent the spread, as state authorities battle to control separate outbreaks in New South Wales, Victoria and the ACT.
The first detection of an H7N3 strain was confirmed on May 22, 2024, at a poultry farm near Meredith, Victoria. By June 24, six other poultry farms in the shire were infected. Tracing activities conducted in May identified a separate H7N9 strain on a poultry farm near Terang.
NSW is responding to outbreaks of H7N8 at farms in the Hawkesbury region, and ACT two detected cases in the Belconnen area. These are unrelated to the Victorian outbreaks.
The Department of Agriculture, Fisheries and Forestry have tamped down fears, saying H7 strains do not appear to easily transition to humans, and the supply of eggs and chicken meat remains safe, if properly prepared.
But along with state and federal biosecurity bodies, they are calling for vigilance from the farm community to prevent a wider outbreak, or the entry of the globally-circulating H5N1 stain. It has already been found circulating in wildlife on every other continent in the world — including Antarctica. It has also infected non-avian species, including humans.
Human-to-human spread has not been confirmed. Yale Medicine infectious disease expert Scott Roberts said the most probable vector was improperly prepared food products.
“There also is no evidence that anyone in the U.S. has gotten bird flu after eating properly handled and cooked poultry products, but the CDC notes that uncooked poultry and poultry products (such as blood) may have caused a small number of H5N1 infections in people in Southeast Asia,” he said.
“Poultry and other animal foods should be safe to eat as long as they are prepared properly. This includes cooking poultry and eggs to an internal temperature of [74°C], which can kill viruses including H5N1.”
The first human case of H5N1 was recorded in a Victorian child in May, reportedly contracted in India. The child has since made a full recovery.
Bird flu is often spread by migratory birds, so the risk of H5N1 reaching Australia will rise in spring. Australia’s interim Centre for Disease Control (CDC) head Professor Paul Kelly said H5 strains were not circulating domestically, but it was important to remain alert.
“The virus now affecting farms in Australia is not the same as the strain of major concern in the United States,” he said.
“In America, we know their virus has spread from birds into cattle and then to humans. These cases in the US have generally been mild, presenting like a case of pink eye.
“But we are watching closely, since the migratory patterns of some birds may bring other strains into Australia. Vigilance is our greatest asset at this time.”
READ MORE:
Disaster management needs more forethought to avoid ‘polycrisis’, government hears