BSE ('Mad Cow Disease') and vCJD “Mad Cow Disease” actually
refers to bovine spongiform encephalopathy (BSE), a disease
first described in 1996 in cattle, which is related to a disease
in humans called variant Creutzfeldt-Jakob disease (vCJD). Both
disorders are universally fatal brain diseases caused by a prion
--a protein particle that lacks nucleic acid (DNA) and is
believed to be the cause of various infectious diseases of the
nervous system. The link between the agent that causes human
deaths from vCJD and outbreaks of BSE in cattle appears to be
dietary consumption of infected cattle products, including beef.
Nonvariant forms of Creutzfeldt-Jakob disease (CJD), which was
described before 1996, still exist and may have one of three
causes: unknown (sporadic form); genetic mutation; or
contaminants introduced during a medical procedure (conventional
sterilization methods may not remove the prion that transmits
the infection). According to the World Health Organization, less
than 5 percent of nonvariant CJD