I had a big time bee keeper in Ga tell me last fall that fumagillin is the cure in the spring and the fall. But I have not heard anything since then. The Jan issue of Be Culture talks about using a 10% bleach solution.(90% water 10%bleach) to kill 100% of the spores. But they have not tested the effects on combs or equipment.
Here in the UK we have recently accepted that Nosema ceranea has been with us for a few years, but because we just considered the problem was caused by the microspoidian N. apis it never occured to scientistis to double check. So when we check for Nosema it is considered that it could bee N.ceranae.
Infection is aggrevated by transporting colonies to new sites where there may be desirable nectar-flow or where pollination is required
Fumidil B is an antibiotic and this is what is reccomended as treatment but why treat with a chemical when it does NOT KILL the spores. Comb change Baily frame change etc helps prevent the spread but if one bee has the spores in the ventriculus (stomach) then defecates in the hive the cycle will start all over again.