BSE Incidence and Control Measures in Great Britain

• The banning of specified ruminant material from animal feedstuffs in Britain (July 1988) led to a dramatic decline in new cases (see figure).
• Cases peaked in 1992 and 1993 at over 30,000 cases/year in Great Britain.
• Confirmed case numbers had declined to 24,000 by 1994, to 14,000 in 1995 and 8,000 in 1996 with a continual decline for the next 4yr.

Click for larger 39k version.

For perspective, the number of cattle in Great Britain averaged over 11 million.

The time lag between control measures (1988) and improved health status (1992) was due, in part, to farmers using up their stocks of cattle feed, but was due mainly to the ~5 year incubation period of the disease.

The delay period between the feed ban and an effect on BSE occurrance of 4-5 years confirmed the hypothesis of disease transmission through infected feedstuffs.

In May, 1996, MAFF proposed steps toward complete exclusion of meat and bone meal from all farm animal feeds. The SBO (Specified bovine offal) 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.