It is estimated that each year in the United States (U.S.), infectious agents cause 9.4 million foodborne illnesses: 5.5 million (59%) foodborne illnesses are caused by viruses, 3.6 million (39%) by bacteria and 0.2 million (2%) by parasites (Scallan et al. 2011). The pathogens that cause most illnesses are norovirus (58%), nontyphoidal Salmonella spp. (11%), C. perfringens (10%), and Campylobacter spp. (9%). Although only a small proportion of these illnesses occur in the setting of outbreaks, outbreak investigations provide valuable information that can help regulatory agencies develop strategies that enhance food safety and prevent further outbreaks related to specifi c pathogens and foods (CDC 2014).