I know there have been some posts on this but I didn't see anything recent that addressed this precise question. I have turkeys for the first time this year. They are confined in a turkey tractor and the chickens are in chicken tractors. I had thought it would be safe to have the chicken tractor go behind the turkeys but not vice versa. Eventually, the turkey tractor would find its way, however, to where chickens had been at some point in the past. Also, I plan to overwinter the turkeys in a pen next to the chickens. I had thought that the parasite that causes this disease would die when the droppings dried out but I am now reading that it may survive for several years if they get into earthworms and something involving the chickens. To date I have gotten all of my chickens directly from hatcheries or a local source that I believe to be safe (they have turkeys plus chickens with no problems to date with the turkeys). I am assuming that if I avoid introducing chickens from swaps or direct purchase other than from hatcheries, they will not be coming in with blackhead as there would be no way for it to get into an egg. Is that the case?