Progressive neurological disorder that afflicts the central
nervous system of cattle, the spread of which the U.S. government continues to prevent in the United States.
Bovine spongiform encephalopahy (BSE) causes animals
infected with it to die because no vaccine or treatment exists.
The source of the epidemic apparently involved animal feed
containing contaminated meat and bone meal in Britain in
1985. The disease has affected herds in Europe since 1985, but
no case has been found in the United States.
BSE is a variant of transmissible spongiform encephalopathy (TSE). Some forms of TSEs—Creutzfeldt-Jakob disease
(CJD), fatal familial insomnia, Gertsmann-StrausslerSeheinker Disease, kuru, and variant Creutzfeldt-Jakob Disease (vCJD)—afflict humans, whereas others affect animals
and are often species-specific. In humans, TSEs cause slow
degeneration of the central nervous system with dementia
and loss of motor skills. According to the World Health Organization, the newly recognized vCJD is strongly linked to
BSE and probably comes from consuming contaminated
beef. All reported cases of BSE and vCJD have been in Europe, primarily in the United Kingdom. Since 1998 there has
been a steady decline in the incidences of both types of cases.
BSE has had far-reaching economic consequences. The
most visible outcome has been the destruction of hundreds of
thousands of cattle throughout Europe. In addition, producers
have experienced losses because of the ban on exporting beef
or beef by-products. Other obvious costs include the establishment of government programs to monitor cattle production
and to establish prevention programs. Much more difficult to
assess are two consequences that are more subtle. The first is
the effect of the loss of consumer confidence and the reduction
in beef consumption. The second is the tension among nations
with the imposition of trade barriers. For example, the United
States has not imported beef from the United Kingdom since
1985, has barred importation of ruminant animals and at-risk
products from nations with confirmed cases of BSE, has
banned the inclusion of mammal-derived animal protein byproducts in cattle feed, and has barred all imports of rendered
animal protein from Europe without regard to species.
—Susan Coleman