There was some confusion this week about bovine spongeform encephalopathy (BSE), or, as it’s commonly known, mad cow disease. Humans who are exposed to it by eating infected animal tissues–the only way it can be contracted–develop a disease called Variant Creutzfeldt-Jakob Disease (VCJD), which is frequently confused with Creutzfeldt-Jakob Disease (CJD), a neurological illness that is not associated with VCJD. California and the United States have a robust surveillance system in place for BSE. In 2011, the California Animal Health and Food Safety Laboratory at UC Davis tested about 8,000 animals from seven western states, with the vast majority coming from California.  Nationwide, about 70,000 tests have occurred since 2009. None were positive for BSE. Just three Americans are known to have contracted VCJD, and none of those cases came from consumption of U.S. beef. To address confusion about suspected CJD in two residents of Marin County,  the health department there issued the following statement (read more). Feb. 10, 2012 CDFA blog