I live in the UK as well,
I am not aware of any Particular problems here with chickens, but I can imagine that infectious bronchitis or any kind of bronchitis could happen more often here due to the constant damp we have in some areas, the same things for humans actually.
I think they would be this harsh just because she has broken the rules. If there was a a problem she could a/ encourage others to break the rules and cause absolute chaos, and b/ introduce any minor problems we have here and cause a spread of anything....
But no we do not have particular problems here as far as I am aware, but the rules are there for a reason.