Always sad to see.
Very difficult to control. From what I have been told, this is as much to do with the fishery as the angler. Their desire for cash over welfare will always take president.
I believe, to eliminate the desease properly is a question of draining and liming the lake. Obviously causing huge cost & loss of income for the fishery. Mmm, it's not going to happen!
As above I ensure all my gear is thoroughly dried, it's all I can do.