A rare case of mad cow disease, also known as bovine spongiform encephalopathy , has been detected at a slaughter plant in South Carolina but poses no threat to humans or other cattle. It is only the seventh confirmed case of the extremely deadly disease ever recorded in the U.S.
BSE is a progressive neurological disorder of cattle caused by proteins called prions; prions are found on the surface of cells, but in diseases like mad cow, these proteins fold abnormally and can cause other, healthy prions to do the same. In BSE, the prions affect proteins in the brain and central nervous system, causing a range of symptoms, including behavioral changes, coordination problems, weight loss, decreased milk production and eventually, death, according to the USDA.
Classical BSE was first discovered in 1986 in the U.K.. The BSE outbreak peaked there in January 1993, when cases spiked to around 1,000 a week, according to the Centers for Disease Control and Prevention.