Chronology and Details of Control Measures in Great Britain

Cases of BSE peaked in 1992 and 1993 at over 36,000 and 34,000 cases in Great Britain. Confirmed case numbers had declined to 24,000 by 1994, to 14,000 in 1995 and are predicted at 8,000 in 1996. BSE peaked in 1991 for 3-year old cattle, in 1992 for 4-year old cattle, in 1993 for 5-year old cattle, in 1994 for 6-year old cattle and in 1995 for 7-year old cattle. (Nature 1996 382:4).

Early control measures (1989) in Britain to prevent potentially infective materials entering the food chain were:

1. The list of specified bovine offals (SBOs) banned for use in the food chain was extended to cover a wider range of potentially infective materials (these are required to be stained with a highly colored, indelible dye).

2. Slaughterhouse requirements were tightened to be sure SBO's were eliminated.

3. Milk from cattle suspected of having BSE was destroyed.

Since 1989 agricultural officials in Great Britain have taken a number of actions to eradicate BSE, including (1) making BSE a notifiable disease, (2) prohibiting the inclusion of ruminant-derived proteins in ruminant feed, (3) destroying all animals showing signs of BSE, (4) prohibiting the consumption of milk from affected or suspect cows by either animals or humans (except for milk from a dam to its calf), and (5) stopping human and animal consumption of certain bovine organs, including brain, spinal cord, spleen, thymus, tonsils, and intestines. Concern about instances of failure to achieve complete removal of the spinal cord led to measures to prevent the use of spinal column (excluding the tail) in the mechanical recovery of meat in Britain.

The United Kingdom Minister of Agriculture, Fisheries and Food (MAFF) stated (November, 1995) that the measures taken were recognized as being sufficient by the World Health Organization, the International Veterinary Organization (the OIE) and the EC Scientific Veterinary Committee. The independent Spongiform Encephalopathy Advisory Committee (SEAC) which advises the UK Government on all aspects of BSE and CJD endorsed the measures and stated that in its view there was no evidence of a link between BSE and CJD.

MAFF believes control of animal feed is the most effective way to eradicate BSE. In January, 1996, the following measures were announced: (1) carcasses of animals aged more than 30 months must be deboned in licensed plants under the supervision of the (British) Meat Hygiene Service, and the trimmings classified as SBOs; (2) the use of ruminant meat and bonemeal in farm animal feed was prohibited. No changes in current food safety advice were recommended. SEAC stressed the importance of proper enforcement of current measures and recommended that the complete removal of spinal cord must be subject to constant supervision.

In May, 1996, MAFF proposed steps toward complete exclusion of meat and bone meal from all farm animal feeds. The SBO was changed to the Specified Bovine Material (SBM) removal requirement which specifies the whole head of bovines as SBM. In addition meat from animals over 30 months of age may not be sold for human consumption. Animals over 30 months will be rendered and incinerated. This represents the cattle at highest risk so these actions should reduce BSE cases by 10-15% in addition to the 40% yearly reduction reported following the SBO. MAFF estimated 1 million high risk cattle will be slaughtered during the first year.

Several countries suspended imports of British beef following the announcement about the possibility of a link between BSE and CJD. As of March 25, 1996, all of the European Union (EU) states except Denmark and Republic of Ireland had banned British beef. Germany also banned imports of beef from Switzerland, which has cases of BSE. The large degree of under reporting of BSE cases in EU member nations make these actions appear to be directed by political and/or economic motives rather than human safety concerns. Genuine safety concerns would be demonstrated by enactment of rules similar to the British SBO in countries with covert or overt BSE.

Proposed rules to limit the use of ruminant derived meat and bone meal in ruminant feeds (similar to the British SBO) were published in the January 3, 1997 Federal Register (Volume 62, Number 2, Page 551-583). Such rules would limit potential spread of prion disease in US cattle from any spontaneous cases or from species in the US which are known to have prion diseases (deer, elk, mink).