Just thought I'd put in my 2 cents on this one. Here in NY state, back
when we had an inspection crew, most parts of beehives found to be
infected with AFB were were destoyed by fire. All bees, frames, comb,
honey, and any other parts that were in poor condition had to be burned
and the ashes buried with 18" soil cover. Tops, bottoms, and supers were
scorched to a depth of about 1/16" on the inside. Before use
the supers had to be scraped down to bare wood. No wax or propolis was
to be left.     There is alot of scorched equipment in NY and I have never
heard anyone suspect it a source of re contamination. When this practice
began back in the early 30's AFB was epidemic in NY. A WNY beekeeper,
Howard Minnic, who was the foreman of the first inspection crew here in
NY, told me that they burned 500 to 750 colonies per week in the 1st
season. Inspection records show that the rate decreased to the 1-3%
range. This rate continued untill spending cutbacks reduced the size of
the inspection force. I have seen similar data from other states.