Hmmm... so yesterday as I was watching someone else's happy bees zooming in and out of my garage, eating honey from my dead hives, I was suddenly worried about the possibility that they are carrying some diseases into the hive. My bees were healthy (died of moisture, cold, and inadequate ventilation) and so I was going to give some of their drawn comb and what is left of their honey to the new nucs I am getting in the spring. I had them stored in the garage but some neighbour bees have found them. Should I worry about disease from these visitor bees?
First, I would close up the boxes. At night, when there are no bees in them, put a solid board on the bottom and a solid board on the top so the bees can't get in. Or a complet block on the entrance and a tight lid (in other words if you have a notched inner cover you have to slide the outer cover back to block it etc.) That way you can give that honey (and work) to YOUR bees when you get them.
Second, there is no more risk of disease than there is from robbers and infiltraters anyway. But yes, disease and mites get spread by robbers all the time. Luckily the mites can't live in your hives without bees as hosts, but AFB spores could get in. I wouldn't worry about it since it's an everpresent issue you can't really control.
But I'd close up the boxes to keep out bees and wax moths. It won't eliminate the wax moths, but the less they get in the better.
Like Micheal says close up the equipment. As for disease well it usually works the other way around. When your bees do the robbing of weak and dying colonies that harbor the disease. But I'm sure it probably is possible for robbers to spread the disease to other colonies, but the likilihood is probably quite low.