I am just learning about listeria, but from what I hear it is extremely difficult to get a production facility clean once it has been contaminated. They almost have to disassemble the whole factory and build a new one. There was some speculation recently that when Walmart mysteriously announced "plumbing problems" at a few stores and that they would be closed for six months, that this was really a listeria outbreak at those stores.
Thanks. wow. Geez that sucks.
Interesting about the Walmart possibility. I just figured they were hitting back at the communist organized wage protests.