Starmom, I am glad that you have sucessfully kept boas and pythons without problems. Using care as you do goes a long way. IBD is not fully understood as far as all the means of transmission go, and airborn transmission has been discussed in research as a possible cause, as has ability of boas to be carriers showing no signs. Since you have acess to data bases as I myself do at the local university perhaps you could do some research and help educate us all. Thanks for your input. I am happy you have healthy snakes and practice good husbandry.
Here is one journal article I found and an excerpt:
"Because
boas may be asymptomatic carriers, some authors advise that
pythons should not be kept together with boas, or even in the
same collection (Bennett 1996, Keeble 2004)." https://netfiles.uiuc.edu/doortiz2/www/IBD.pdf
The references for this article will provide anyone interested with acess to journal databases a lot of peer reviewed journal articles for education.