Locating the Source of Large-scale Diffusion of Foodborne Contamination

Abigail L. Horn; Hanno Friedrich

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arXiv · 1805.03137

Locating the Source of Large-scale Diffusion of Foodborne Contamination

Abigail L. Horn·Hanno Friedrich

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Abstract

We study the problem of identifying the source of emerging large-scale outbreaks of foodborne disease. To solve the source identification problem we formulate a probabilistic model of the contamination diffusion process as a random walk on a network and derive the maximum likelihood estimator for the source location. By modeling the transmission process as a random walk, we are able to develop a novel, computationally tractable solution that accounts for all possible paths of travel through the network. This is in contrast to existing approaches to network source identification, which assume that the contamination travels along either the shortest or highest probability paths. We demonstrate the benefits of the multiple-paths approach through application to different network topologies, including stylized models of food supply network structure and real data from the 2011 EHEC outbreak in Germany. We show significant improvements in accuracy and reliability compared with the relevant state-of-the-art approach to source identification. Beyond foodborne disease, these methods should find application in identifying the source of spread in network-based diffusion processes more generally, including in networks not well approximated by tree-like structure.

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Abigail L. Horn, Hanno Friedrich. 2018-05-08. Locating the Source of Large-scale Diffusion of Foodborne Contamination. https://arxiv.org/abs/1805.03137

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