I have no idea. Baby birds aren’t an area I know anything about honestly.
Hopefully someone more knowledgeable chimes in! @nuthatched do you have any helpful advice?
No, they won’t affect you, but they can make the bird weak. They’re tiny little bugs that would be crawling on it. Check under feathers if you can. They may crawl on your hand if it’s bad, but they’re not going to hurt you, it’s just gross.