One frequently used approach to foodborne disease attribution is the use of expert elicitation. During expert elicitation, a group of experts is asked, based on their professional judgment, to either rank food groups as to their relative important as sources of foodborne disease or to estimate the percent contribution of food groups to foodborne disease. The reliability of expert opinion regarding foodborne disease attribution has been questioned since it is based on perception and not quantifiable data (Batz et al. 2005). However, by selecting experts with first-hand knowledge of different aspects of foodborne attribution (e.g. experts working in academia, the food industry, and public health) it is possible to obtain an informed and integrated judgment of the impact of different food types of human illness. Moreover, expert judgment is often the best source for guidance when scientific and epidemiologic data are sparse (Batz et al. 2005, National Academy of Sciences 2003). We briefly review the results of two recent expert elicitations.

Karns et al. (2007) conducted an expert elicitation for FSIS to determine foodborne disease illness attribution for 25 meat and poultry food categories. In what follows this study is referred to as the FSIS expert elicitation. The expert panel consisted of 12 experts equally divided among scientists from the public health community, industry, and academic institutions. The expert panelists were asked to attribute foodborne illnesses of Salmonella, E. coli O157:H7, and Listeria monocytogenes to handling and consuming foods in 25 processed meat and poultry product categories. The attributions obtained for the Karns et al. (2007) study are presented in Table 2-1.