This link gives us something to think about. We are going to get bit by this someday. The article sounds a little bias against agriculture. They blame ag for 20% of the problem. They don't mention what causes the other 80%. I'll bet hospitals.
http://www.agriview.com/articles/2007/1 ... tock04.txt
http://www.agriview.com/articles/2007/1 ... tock04.txt