Is bird flu infecting humans? How would we know?

Bird flu is circulating among birds on the Australian mainland.

So with the confirmed number of detections growing , you may be wondering about the risk of birds infecting humans.

So far in 2026, no humans in Australia have been diagnosed with the currently circulating strain.

And evidence from overseas indicates that in the rare situation this would occur, illness would generally be mild .

But not everyone with flu-like symptoms gets tested.

And even if they did, a general flu test cannot distinguish between bird flu and seasonal flu.

So how would we know if a human caught bird flu from an infected bird? What is bird flu? What’s changed? Bird flu (or avian influenza) refers to strains of flu viruses that mainly affect birds.

The current strain of concern is known as H5N1.

Since 2020, a sub-strain of H5N1, known as 2.3.4.4b, has been circulating around the world .

This has resulted in the deaths of millions of birds (including poultry).

It has also crossed into other species, including dairy cows in the United States, and marine mammals.

Distressingly, mass mortality events – where many animals die suddenly – have been reported.

In June, the first cases of H5N1 influenza were reported in Australia, first in migratory birds, then in local wild birds.

Now, the government does not report case numbers, just events , where one or more birds may be involved.