You can't really speculate what caused it, as the article says.
All food has bacteria. Every surface we touch has bacteria, viruses, grime, etc. It's just that usually (you hope) it isn't in a condition to grow enough to cause illness. The food is kept cold or hot enough to keep the bacteria in check. You wash your hands after handling things so you don't catch the cold or flu.
Leek
SAVING ONE DOG may not change the world,
but it CHANGES THE WORLD for that one dog.
American Brittany Rescue always needs foster homes. Please think about helping that one dog.
http://www.americanbrittanyrescue.org