A Gravity-Based Approach to Connect Food Retailers with Consumers for Traceback Models of Food-Borne Diseases.

Computational traceback models are important tools for investigations of widespread food-borne disease outbreaks as they help to determine the causative outbreak location and food item. In an attempt to understand the entire food supply chain from farm to fork, however, these models have paid little attention to consumer behavior and mobility, instead making the simplifying assumption that consumers shop in their home location. This paper aims to fill this gap by modelling food-flows from supermarkets to consumers in a large-scale gravity model for Hesse, Germany. Modelling results show that on average, groceries are sourced from two to four postal zones with half of all goods originating from non-home postal zones. The results contribute to a better understanding of the last link in the food supply chain. In practice, this allows investigators to relate reported outbreak cases with sourcing zones and respective food-retailers. The inclusion of this information into existing models is expected to improve their performance.