Healthy hives 6 days ago.
6 days later obvious EFB.
If I hadn't done frequent hive inspections those hives would be totally screwed.
The good news is that in hives treated with OTC, I see full recovery within the same amount of time. Sets the hive back 1 week or so, but I've never seen any lasting effects from EFB as long as I give them at least 2 treatments.
This is definitely one of those instances where I wish I had my hives spread out around an entire yard, rather than in a cluster behind a bear fence.
Almost always - two or more hives hives situated next to one another in a line all catch EFB.