A Review of the BSE Epidemic in British Cattle

ABSTRACT Bovine spongiform encephalopathy (BSE) was first diagnosed in British cattle in 1986. The infectious agents of transmissible spongiform encephalopathy (TSE) diseases are believed to be infectious proteins or prions. They can remain infectious despite exposures to disinfectants, autoclaving, radiation, and ultraviolet light. TSEs affect animals as well as humans and are characterized by progressively severe psychomotor dysfunction and long incubation periods. As of August 27, 1999, 175,404 cases of BSE have been confirmed in Great Britain with 1,787 additional confirmed cases in Northern Ireland (as of August 31, 1999). Mathematical and statistical analyses of the BSE epidemic data suggest that the incidence of BSE in Great Britain and Northern Ireland will continue its rapid decline. Evidence relating to maternal and horizontal transmission of BSE is discussed. Public concern remains focused on the probable link between BSE infection in cattle and a new variant of Creutzfeldt‐Jakob Disease (vCJD) in humans, another TSE. Given the long and variable incubation periods associated with TSEs, and a possible genetic component, the eventual magnitude of this human epidemic remains uncertain.