It's a funny pathogen afb, it's not actually that infectious, it's deadliest attribute is physical in that the bees struggle to clean the gloop left by a collapsed larvae and so end up reinfecting other larvae due to sticky crap all over their mouthpieces. Given the use of a bucket and spade they'd have little bother with an odd larvae dying of the bacteria.
There's a great paper from upsalla University where they relate evidence of many colonies getting better after shook swarming despite initially still showing high counts of the causative agent by pcr tests, those which didn't develop clinical symptoms rid themselves of any detectable signs of the disease in 6 months.
There's a great paper from upsalla University where they relate evidence of many colonies getting better after shook swarming despite initially still showing high counts of the causative agent by pcr tests, those which didn't develop clinical symptoms rid themselves of any detectable signs of the disease in 6 months.