I think this came out of my chicken

[Perris]

Not as in a viral spread, but via dirty nesting material it can be spread as the cloaca will bulge out when the egg is laid and the mucosa can easily suck in dirt up the oviduct when retracting.

So keeping the hens' butt clean and cleaning out the nest boxes often can help to prevent the spreading.

that's good general advice, but not relevant here as it was dropped with feces below the roost, not in the nest box

It was below where my chickens perch

as is the case with lash egg material here too.