For those that don’t want to bother reading the article, to avoid listeria you should buy fresh and local whenever possible, avoiding prepared foods (especially those stored chilled for longer periods of time during shipping)and avoid storing chilled foods for long periods of time even if the shelf life indicates they would otherwise okay. Listeria thrives in cooler temps.
Mostmaps people use to make some point, especially some political point, turn out to just be population density maps.