Salpingitis is bacterial. It's not contagious in the usual way, like virus's. I've never seen any signs of it spreading amongst birds in my flock. Someone asked a while back if a rooster could spread it among hens, and I've never seen any signs of that. It seems to sporadically hit some hens, not all. If a rooster were spreading it I would expect more hens to get it, and that hasn't been the case. There isn't good information about it, but most seem to feel that it's bacteria somehow getting back up the oviduct from looser cloaca's, maybe from unknown ways the oviduct itself is built. There is information on what it IS, but not much on the actual mechanics of the cause. There is also differing opinions on the type of bacteria causing it, so likely it can be one of several. I don't think you need to worry about that.
