No idea. My understanding is that there aren’t (in Australia) but this is not a question I’m qualified to answer.
That being said, there are tens of thousands of Australian backyards with chooks in them. We’ve all heard of H5N1 Avian Influenza but I’m sure that we’d be informed by our government (and advised what to do) if it was ever found in this country.
If you go to the Federal Government Department of Agriculture, Fisheries and Forestry website they have a lot more info.