Joe:
The condition does apparently start in the wild. At some point in this thread or somewhere (an article on ReefKeeping?) of photos I took at a Jakarta exporter that show one out of hundreds of elegance corals showing the signs of the disease. We saw no unhealthy ones in the field or in the tanks of holding facilties. But, if there is one area where there are sick corals and then hundreds are put in the same tank, and I know this is a contagious condition, then you have as Carl mentioned, exposed every coral in the system. This type of disease spread is very common, and wholesalers and retailers often put them in the same tanks, too. There is the "SPS" tank and the "LPS" tank and the "soft coral" tank....well, if you get a disease, and then put all susceptible species right next to each other in the same small space, you get elegance coral syndrome, "RTN", Xenia melting, soft coral rottings, Brown Jelly on LPS, etc. that we see so commonly in stores, in our own tanks, and you can imagine at the larger scale. Let me post the image again so you can see how corals are typically held.