Looks like it to me, too, from your picture. But other things can look like EFB, especially in a single photo. There is only rarely a smell. Twisted, discolored larvae that eventually turn to goo; dried scales that are easy to remove, and no roping are the cardinal signs. What catches my eye in an EFB colony is that the queen may be laying, and young larvae (1-3 days since hatching) are seen but there is an absence of the late-stage, fat, pearly-white larvae, because most of them are dying before they reach that age. A few that are infected late (or more resistant) may begin pupating but die under the cappings so a few cells with holes are sometimes seen with EFB. But, unlike AFB, most infected brood dies before it is capped, so you won't see swathes of perforated cappings like you would with AFB.
I would immediately test that hive with one of the Vita field test kits. Buy two in case you mess up the first one inadvertently; they are not hard to do, but you would't want to wait out another shipping period. You need answers as fast as possible. You can also send a comb to Beltsville (and perhaps some place closer to you out west.)
And also immediately put in place strict practices to avoid spreading it to another hive: separate tools and gloves; move no equipment or bees from this hive to any other; prevent robbing; do whatever it takes to prevent a swarm from leaving your apiary (all hives, not just this one.)
If you have a state bee-inspection system, call for an inspection. Start trying to line up a vet who can prescribe antibiotics if you are willing to go that route. At a minimum, you will need a full set of fresh equipment to shake these bees into.
Don't dither. Even if you don't want to do anything (such as treat or do a shook swarm), you must know what you are dealing with.
EFB sucks!
Nancy
