This is the eBook version of the printed book. This Element is an excerpt from Germs, Genes, & Civilization: How Epidemics Shaped Who We Are Today (9780137019960) by David P. Clark. Available in print and digital formats. ¿ From E.coli and norovirus to Salmonella and mad cow disease: the reality of meat-borne infection, and what can be done to prevent it. ¿ Some 80 million cases of foodborne disease occur in the U.S. annually. One factor: the ever-increasing centralization of food processing. If one cow in a thousand carries Salmonella and the meat is sold by local butchers, only a handful of people get sick. But if thousands of cows are processed centrally and their meat is mixed together, it all becomes contaminated.