It has been scientifically established that the strains of agent causing bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) are indistinguishable, and the most plausible explanation, although not yet proven, is that BSE transmitted to humans via contaminated meat or meat products. In 2002, the World Health Organisation published consumer information, which states that the consumption of contaminated meat and other food products from cattle with BSE is presumed to be the cause of vCJD in humans.
The United Kingdom has in place stringent controls to minimise the risk of the BSE agent getting into the food chain. These include a ban on mammalian and other processed animal proteins being fed to farmed livestock; the specified risk material (SRM) controls that prohibit from human consumption those parts of the animal that might harbour BSE; and the over 30 months rule that does not permit most older animals to enter the food chain. The Beef Assurance Scheme does allow a few older animals into the food chain, if reared from grass in beef herds, subject to special rules. All measures currently in place are rigorously enforced, for example by members of the Meat Hygiene Service supervising activity at abattoirs.