You can have a fairly strong hive that may only have a few SHBs and then one day your bees swarm or something, anything to give them a chance and they can destroy a hive. I don't know about in Va. but down here I think they are almost every where. You just do what you can to keep their numbers as low as possible, sometimes you may not have any. You keep a check on them, mites, and in general how your hives are doing on a regular basis. Thats what you do as a beek. Good luck with your bees.
Joe