The European Foul Brood is a Bacteria that is in the cell.
When the egg hatches the larva is infected.
It dies before the cell is capped.
It is easy to spot.
When looking at capped larva you will see a few empty cells among the capped ones.
Like when a hygienic bees clean the cells of varroa mites.
When you see this look closely at your uncapped brood
The larva isn't a glistening white like a healthy larva.
It will be just on the verge of being capped, an off white to greyish to a tan and not capped.
They had me isolate the queen for 10 days to break the brood pattern.
So far the hives that were infected are doing great.