According to article,,, they do not have a conclusive result of cause of outbreak. Speculations are rampant. Virus,,, bacteria,, or anything else.

Did rule out Avian flue and West Nile, and no mention of Newcastle.
Article did state that the fatality occurrence of the bird is soon.
If I found a bird carcass on the ground, Yes, I would dispose of it in best secure manner. Similarly like I use plastic bags to pick up Doggie Donuts.

Article is good to read to give peeps a heads up to be CAREFUL.
Some things we are not able to protect ourselves even in our best efforts. I cant live in a bubble, and my flock likewise. I still feed my songbirds,,,,,,, stopping that would cause starvation possibilities (or at least diminished health due to malnutrition) since these lil feathered friends are dependent on me.

And I am dependent on them to provide me viewing pleasure and enjoyment.
On the subject of Bio-security,,,,, when I visit other local chicken keepers,, (not those next door) ,,,, I wear fresh clothing that has not been in contact with my flock chickens that day. This way person has peace of mind that I did not bring something unwanted with me.

Its not as secure procedure that Dept, of Agriculture Inspectors take, when inspecting huge facilities. But it is best that I can do.