I never had any birds sick from LLV, directly or indirectly, today.
If tests weren't so expensive, I would have mine all tested but no one was ever sick.
The only time I ever tested positive was ONE....she was from a well known breeder and the breeder was in denial about it the whole time about the existance of LLV.
At first, paranoia set in but after a while, with no birds being dead or dying from LLV, I relaxed a bit and realized it is a chance I take. Only the strongest will continue on. Carla has more information on LLV. From what she told me, incubate, hatching chicks separately from the other breeds with unknown LLV or non existant LLV flock. I think that is the only time it would infect the other chicks of a different breed.
Overall, just keep in mind if you are working with these Spitzhaubens. I am hoping one day we shall get rid of LLV with keeping the strongest and the weakest not ever produce or culled out. or a vaccination. It is not much differnt than MS/MG that is about 80 percent of our flock in the US having it.