European Foulbrood: not recovering on own during honeyflow
I have an apiary with 20 Minnesota hygenic hives. They all built up really well in the spring. A four weeks ago, several had their first supers in place, I had one hive that showed "yucky brood" upon inspection. Three weeks ago, seven hives showed "yucky brood". I have never had brood diseases before, so I researched. I suspected European Foulbrood (EFB). I cut comb and sent samples to the U.S. Department of Agriculture Bee Research Lab in Beltsville, Maryland. Six out of seven tested positive for EFB (the other nothing).
The University of Minnesota Bee Healthy On-line course says the EFB is a stress disease and goes usually goes away with honeyflow. First response would be to feed the hive. Even though the honeyflow had started, I fed all the hives in the apiary for two weeks (1:1 sugar water). They still show yucky brood.
I am not sure what to do at this point. My options:
1) Do nothing.
2) Do nothing but get what honey I can out of them, don't winter them, kill them in the fall.
3) Burn the hives now.
4) Shake the hives onto new frames. I only have new ones, so they have LOTS of work to do if I am going to winter them. If they don't make enough, and I don't winter them, I could wind up with EFB-tainted frames.
6) Give them Terramycin now and get NO honey from them and probably NOT 'solve' the problem and it would just reoccur with stress.