Volume 1: Findings and Conclusions
Executive Summary of the Report of the Inquiry
4. Assessment of risk posed by BSE to humans

• One of the most significant features of BSE and other TSEs is the fact that they are diseases with very long incubation periods. Thus the question whether BSE was transmissible to humans was unlikely to be answered with any certainty for many years, and scientific experiments were bound to take a long time. The Government had to deal with BSE against this background of uncertainty as to the transmissibility of the disease.
• MAFF officials appreciated from the outset the possibility that BSE might have implications for human health.
• By the end of 1987 MAFF officials had become concerned as to whether it was acceptable for cattle showing signs of BSE to be slaughtered for human consumption. However, the Department of Health (DH) was not asked to collaborate with MAFF in considering the implications that BSE had for human health. It should have been.
• Only in March 1988, by which time MAFF officials had advised their Minister that animals showing signs of BSE should be destroyed and compensation paid, did MAFF advise the Chief Medical Officer (CMO) Sir Donald Acheson of the emergence of BSE and ask him for his view of the possible human health implications.
• On Sir Donald's advice, an expert working party, chaired by Sir Richard Southwood, was set up to advise on the implications of BSE. After their first meeting in June 1988, the Southwood Working Party advised that cattle showing signs of BSE should be slaughtered and destroyed. This advice was of crucial importance in safeguarding human health. The Working Party had concerns about some occupational health risks in relation to BSE and some risks posed by medicinal products. They notified the responsible authorities of these concerns. On 9 February 1989 they submitted a Report to the Government in the knowledge that it would be published. The report concluded that the risk of transmission of BSE to humans appeared remote and that 'it was most unlikely that BSE would have any implications for human health'.
• This assessment of risk was made on the following basis:

- BSE was probably derived from scrapie and could be expected to behave like scrapie. Scrapie had not been transmitted to humans in over 200 years and so BSE was not likely to transmit either.
- So far as occupational and medicinal risks were concerned, the authorities which had been notified about these could be relied upon to take appropriate measures to address them.

• The Report did not, as it should have done, make clear the basis for its assessment of risk. It did comment that if the assessment was incorrect the implications would be extremely serious. This warning was lost from sight. The Southwood Report was, in years to come, repeatedly cited as constituting a scientific appraisal that the risks posed by BSE to humans were remote and that no precautionary measures were needed other than those recommended by the Working Party.
• Precautionary measures were nonetheless put in place that went beyond those recommended by the Working Party. The wisdom of those measures was demonstrated as the years went by and facts were learned about BSE which threw doubt on the theory both that it was derived from scrapie and that it would behave like scrapie.
• In May 1990 a domestic cat was diagnosed as suffering from a 'scrapie-like' spongiform encephalopathy. This generated widespread public and media concern that BSE had been transmitted to the cat and might also be transmissible to humans. Subsequently, more domestic cats were similarly diagnosed. These events shifted the perception of some scientists of the likelihood that BSE might be transmissible to humans. By 1994 the Spongiform Encephalopathy Advisory Committee (SEAC) evaluated the risk of transmissibility to humans as remote only because precautionary measures had been put in place.