The major issue is plant viruses: hippeastrum mosaic virus, cucumber mosaic virus, tomato spotted wilt virus and tobacco mosaic virus which are transmitted by sucking insects. There's no cure for these infections which weaken and eventually kill the plant. Amaryllis are also affected by various bacterial and fungal diseases which can be be fatal if not treated aggressively. Mine are all planted outside so they do show disease and insect damage. I would never send one of my bulbs to another gardener, since I wouldn't want to unintentionally pass on a problem. Keeping them in pots helps in terms of good cultural practice but if they are outside during the summer, they can still be exposed to issues. You assume that you are getting healthy, virus free, bulbs from commercial nurseries, but buyer beware. Very rarely, a sick bulb can slip through and the nurseries want to be notified so they can check their stock. Unfortunately, it could be several weeks before you realize that there is a serious problem. During this time, the sick bulb has been in close proximity to other bulbs. This is situation where a quarantine space would be a good idea for new acquisitions. I think I am going to start following my own advice.
