Why has Australia never detected bird flu?

Scientists have given many explanations for why Australia and the entire Oceania region remain unaffected by bird flu.

While the H5N1 bird flu epidemic is raging around the world, Australia and the entire Oceania region remain unaffected . Scientists have offered many explanations for this phenomenon.

 Researchers inspect the area where cases of A H5N1 influenza were found in Antarctica, March 2024. (Photo: AFP/VNA)

According to Mr. Frank Wong, a virologist at the Australian Animal Disease Center in Geelong, Australia's isolated location and policy of not importing live poultry have helped it avoid the disease . In addition , many bird species here are endemic and do not migrate to areas where the disease is present.

However, Dr Michelle Wille from the University of Melbourne said it was only a matter of time before the virus reached Australia. Long-distance migratory birds such as seabirds and shorebirds from Siberia and Alaska through Southeast Asia to Australia could be potential sources of infection.

To proactively prevent the disease, Australian scientists have begun testing nearly 1,000 migratory birds. They will capture seagulls in 7 locations stretching from the Northwest to the Southeast of the country to test for viruses, especially the H5N1 strain 2.3.4.4b that has caused mass deaths in birds and some mammals.

Additionally, ducks are also thought to be carriers of the disease . Ducks are more resistant to the virus due to their special immune mechanisms, so they can transmit it without getting sick. Fortunately, however, most ducks in Oceania are endemic and do not migrate abroad.

Another reason given is the biological divide along the 'Wallace line' that runs through Indonesia. Many animals live only on one side of this divide, creating a difference in fauna between the two regions.

This may have left the virus unadapted to species east of Wallace's Line, including Australia.

However, some duck species such as Pacific yellow-billed ducks and spotted geese can still travel across Wallace Road, potentially bringing the H5N1 virus into the area.

Experts warn that if the virus is detected, the government will quickly cull affected poultry, as it did with the H7N3 and H7N9 strains in Victoria in May. However, the impact of the disease on Australia's ecosystem remains a major unknown that requires further research.