The primary vector for this disease in captivity is snake mites. While these pests are very rare in the wild, they are unfortunately common at import, jobber, wholesale and retail facilities that get a large volume of ophidian traffic. So if you get your babies right from Africa, or better yet, a reputable US breeder, you probably have little to worry about. However, if you happen to get them through one of the other facilites, there is a chance that they will have mites. However, mites are initially very easily cured with provent-a-mite and good hygene. Fortunately, IBD in balls is relatively uncommon and they show signs of the disease very quickly, within weeks actually. So, keep an eye out for neurological abnormalities such as tremors, star gazing, a poor righting reflex (when the snake is turned over, it should attempt to right itself immediately), inability to hit prey and a loss of coordination. Any snake that has these symptoms should be isolated immediately. You don't have to worry about eutanizing bps with IBD, as they will die on their own in short order. The key is to quarantine all new aquisitions in a seperate room for at least a month (preferably several) before they introduced into the main snake room. That way, problem animals can be isolated and dealt with before they spread the plague. Good luck.
Will