Oh no, I'm so sorry you had to go through that and make that decision.

I have only dealt one time with wet pox and it sure is brutal and depressing. We haven't had as bad of an issue with mosquitoes this year thankfully, but OMG the flies!!! SOOO many flies. I am hopeful that you are right that you only have the one baby that got it and the rest are just fine!
I have been feeling super sad...when we were all down with COVID and couldn't check on the birds as often, I lost two of my perpetual broody hens that clearly overheated and didn't leave their nests enough.

One of them was Goldie my Salmon Faverolle, and one of them was my sweet, sweet dedicated silkie Fuzzbert.

I've had her since I first started chickens and I was just devastated when I found her. It's just so tough when they are so broody, every day is over 100, they started molting, and won't break and get out of their coops enough! We just couldn't manage with everyone down and sick. I literally didn't leave my bed for two days straight. Despite misters, and water, and shade, and electrolytes...if they won't care for themselves so much is on you to keep them alive! I just brought in Big Momma for two days inside because she's been broody and lost weight and her comb was paler than normal. She got a bunch of vitamins mixed in with eggs and egg shells, AC for a couple days, and some harassment from Aria (hugs and forced love) and she is back outside now looking much better. Orpingtons are much easier to break than silkies in my experience! They at least take some time off before going broody again...every time I tried breaking Fuzzy she just went right back. Blah.
@TropicalBabies I'm so sorry you have to consider thinning the flock! I cannot imagine you having to let go of Spider!! I hope you are able to find a way to keep him!