Microbial pathogens have been estimated, in a study published in 1999, to cause about 76 million cases of foodborne illnesses annually in the United States, including an estimated 325,000 and 5,000 cases that result in hospitalizations and deaths, respectively (Mead et al., 1999). A better understanding of foodborne disease transmission, including accurate estimates of attribution of foodborne illnesses to sources, are sorely needed to improve our ability to better control and prevent foodborne …