" wonder if there’s any way to know if the rapid spread of Covid19 in Italy had anything to do with cultural habits like bringing your own grocery bags to the store? :)"
Well, I can honestly say my bags have not been to China. :) When you cram that many people into a small area, northern Italy, any kind of infectious outbreak will spread very quickly. Plus, lots and lots of old people. I read that most of the fatalities in Italy were people over 85 and the overwhelming percentage of them also had contributing factors: heart disease, diabetes, respiratory problems.
"I have no control over where everyone else’s bags have been before being placed in the common area where mine will be."
Do you have any control over where all that food came from, and how it was handled before being placed on the shelves?
