George,
The answer is in BCI's flyway and banding data. Most bats don't travel that widely, particularly in the east. But *some* have. Indeed, the one site in TN was from a bat species NEVER recorded in the cave before. Certainly that doesn't mean a caver didn't transport to hamilton, but it doesn't mean a caver had too either. Plus, given that we haven't seen a continuation of that trend, we are forced to conclude that if people are carrying GD, We aren't very dang good at it.