Over two decades, I've seen a sick/ dying wren twice. Both times that bird vanished, the bird feeders came in, and the neighbors also stopped feeding wild birds for a month. MG, if it arrives, spreads at bird feeders, and the little wild wrens die of it.
Mary
The wild wrens enter my coop when they can, and it's a constant battle keeping mites at bay because of these interactions.
Mycoplasma gallisepticum is a bad disease for chickens, and can be brought in by those birds too. I don't know if your poultry will be at risk though.
I do feed the wild...