A landmark study, published as “The Effectiveness of Hygiene Procedures for Prevention of Cross-Contamination from Chicken Carcasses in the Domestic Kitchen,” put this question to the test. Researchers visited five dozen homes, gave each family a raw chicken, and asked them to cook it. After the bird was cooked, researchers returned to find bacteria from chicken feces—Salmonella and Campylobacter, both serious human pathogens—all over the families’ kitchens: on the cutting board, utensils, cupboard, the refrigerator handle, the oven handle, the doorknob, and so on.
