The fish which survive to this disease gets imunity but can spread the virus.
Last december I had 6 happy discus in my 75 gal tank and I bought 2 other from a local breeder(because bobby is so much involved on this forum I have too mention that IS NOT BOBBY). The fish were absoluty gorgeous but it looks like they spread the virus in my tank. After 2-3 days all the other discus start to blacken, the 2 new discus were OK. I start to treat all tank with Eritromicin, half dose because I had Cardinal Tetra in that tank. I've lost 3 discus but I saved other 3. The 2 new discus were unafected by the virus.
I can't say nothing about the fish at Sierra because I didn't see them, but anybody can have their own conclusions.
Looking forward to hear more opinions from the discus people on this forum.
Late edit after saw protcl's posting: Protcl please don't jump to any conclusion before positevely identify your fish problem. They maybe only stressed...Compare your fish with the pictures available online.