Very good advice because you definitely have AFB in that hive. 10framers advice about the sterilization of tools is excellent and a point that is often overlooked which results in spreading the disease. Sterilizing the tools used on a hive found to be infected with AFB must be done ASAP and at the very least should be immediately set aside until they are sanitized and another set used.
A beekeeper aware of the effects and possibility of AFB always has a spare hive tool, gloves (if used), and smoker in case.
A hive found to be infected with AFB should be destroyed as soon as possible avoid further infection of the apiary. The apiary should be quarantined and frequent inspections made for at least 30 days after destroying the infected hive. The tools used in inspecting the quarantined apiary should only be used in that bee yard, sterilized after each, until one is confident that the threat of further AFB infection is past.
Large populations of bees in each hive is the best prevention against disease as a strong hive usually has the ability to defeat most bee diseases as long as it remains strong. Once a hive begins to weaken it becomes more susceptible to bee diseases.