Never got your answer, eh. Well, I've read that typically the mites are gone by the time of sale. This would only be do to a cleaning of the cheese, as once mites establish, they're pretty much there. They won't likely do damage to other cheeses once at the store as they go dormant in cold temperature. English cheddar is well known for them, and point of fact, any natural rind aged cheese is likely to find them. They really do wonders for a cheese, keeping the rind free of molds.