Foot-and-mouth disease (FMD) is the most highly infectious animal disease known: nearly 100 percent of exposed animals become infected with it. Although the United States has not had an outbreak of FMD since 1929, a single outbreak of FMD virus as a result of an accidental or intentional release from a laboratory on the U.S. mainland could have significant consequences for U.S. agriculture. The traditional approach to the disease, once infection is confirmed, is to depopulate infected and potentially infected livestock herds to eradicate the disease. The value of U.S. livestock sales was $140 billion in 2007; about 10 percent of this figure, or approximately $13 billion, was accounted for by export markets. The Plum Island Animal Disease Center (PIADC), on a federally owned island off the northern tip of Long Island, New York, is the only facility in the United States that studies the live FMD virus. The U.S. Department of Agriculture (USDA) was responsible for the PIADC from its opening in the 1950s until June 2003, when USDA transferred responsibility for it to the U.S. Department of Homeland Security (DHS), as required by the Homeland Security Act of 2002. The act specified that USDA would continue to have access to Plum Island to conduct diagnostic and research work on foreign animal diseases, and it authorized the president to transfer funds from USDA to DHS to operate the PIADC.