older but still interesting discussion we had on fauna about it - I shared pics in that thread of a retic with IBD that someone had given me permission to post.
http://www.faunaclassifieds.com/forums/showthread.php?t=309529
I've heard first hand accounts of people having to euthanize their entire collection due to crypto outbreaks and destroy all equipment but in my 20 years involved with boas and other boa keepers, never heard much about anyone having IBD and no one directly that I know. I keep hearing rumors like those posted above but never hear any proof or stories about it. I highly doubt "35- 40% of the CB Boa population carries the virus" but I don't really know of course.
Having gone through my own IBD scare, boa showing neuro symptoms, I closed my collection for 5 years and that boa was euthanized and another that died for unrelated causes both had full necropsy and tissue samples tested for IBD, luckily negative in my collection.
It's wonderful that there is a blood test for it now! I'm not saying take it lightly but I think people are overly worried about it at the same time. Doesn't help that there are many other issues and causes that mimic some of the neuro symptoms so the first thing people think is 'omg it has IBD'. It is a very scary thing that I hope to never have to deal with.
edit to add - as far as I know - it's still not 100% determined how it's passed. I don't know if Dr Jacobson is still working on it or not