Hi Kitta

Yes, any empty brood comb.

Hooper was working a large number of colonies and that risks the spread of disease. In general, if you are operating a closed system by taking precautions when you visit other beekeepers or they visit you, the risk of serious disease will be low. Do brood disease inspections though. I'd still fumigate empty brood comb (having removed any sealed cells) but I don't think that it is necessary for supers. However if I was a large-scale operator with known EFB I'd be replacing comb like crazy.

Fumigating brood comb gives advantages for the control of viruses, Nosema and EFB (when it is around in the area and so might be on the comb at a low level, not symptomatic disease in the colony). In super frames there might be EFB in honey but not having had brood or young bees I don't think that there is a high risk of the other things.

best wishes

Gavin