In response to the discovery of a BSE-infected cow in Washington State in December 2003, the U.S. Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) commissioned the Harvard Center for Risk Analysis (HCRA) to use the Harvard Bovine Spongiform Encephelopathy (BSE) simulation model to investigate the impact of alternative measures to mitigate exposure of the human population to the BSE agent.