I read something from Bill Marler (who is a food safety lawyer) the other day that said warming waters have led to an increase in food poisoning in relation to oysters. He also mentions pre-packaged foods. I’m not sure what happens in the US, but I’ve noticed much of our produce is now imported. So fruits and vegetables come in from overseas, even the bagged stuff. That means that lettuce you bought in a bag may have been washed in unclean water, or have been packaged in conditions that wouldn’t be acceptable in Australia or the US. Hands not washed etc.