I also cannot help you with information about local Nosema problems in your area or details about treatment and its effects. The identification method proposed by O.G. Marti is certainly a good one but it's a lot of work if you want to screen a lot of bees for Nosema. You can bypass the grinding filtering and centrifuging by just quick killing bees (freezing is probably the easiest method), dissecting out their midgut - the broad section of their insestine - and examining a few drops of the midgut contents under your microscope. Heavy infections will also show up in feces. I have examined lots of field caught bumble bees for Nosema, and spores are visible even at 200X magnification. In addition, after you've seen it a few times you'll probably be ably to note heavy infections just by the milky colour of the midgut. The only thing I know of that you could confuse with Nosema are fungal spores, but they are much more variable in size and shape than are Nosema spores. Jacqui Shykoff