Originally, the Government's advisers - the spongiform encephalopathy advisory committee (Seac) - decided that BSE was probably passed on only in feed and that when the infectivity of the feed stopped in 1988, so would the BSE epidemic. But at the moment we do not know whether this optimistic belief is, in fact, soundly based.
Likewise, Seac felt that BSE would not be passed from cow to calf during pregnancy. We now find that large numbers of cattle, which are the offspring of infected cattle, go on to develop BSE.
Originally, Seac felt that BSE-infected cattle would not transmit their infection to humans. This was because tissues injected into mice produced no ill-effect in the mice. Yet a single human meal of such a tissue could contain 30,000 infective units (where one unit is enough for a cow to infect another cow). In other words, it is impossible from these experiments to prove that there is not enough present in a single meal to infect a human.
The Advisory Committee on Dangerous Pathogens implicitly recognised the uncertainty in 1994. It stated that if certain tissues (which we were still eating) were considered as being possibly from a cow that was infected with BSE, then they should not be handled without gloves, should be acted on in a fume cabinet, and the person dealing with them should probably wear a face mask. At that time, we were eating 250,000 livers from infected cattle.
Seac's original decisions were optimistic but reasonable. They have turned out to be wrong or ill-informed. The repeated tightening of the restrictions on beef manufacture has made the previous restrictions clearly inadequate.
The Ministry of Agriculture has produced a huge increase in the amount of food grown in the UK. It has done this by bringing in good methods and spreading them throughout the agricultural world. Food is spread from one part of the UK to another. Good markets and low margins have led to excellent food in the UK that is relatively cheap. The problem is that if something goes wrong then a whole industry collapses and a whole country is put at risk.
BSE should now be considered a threat to public health and should be handled by the Department of Health. It should be made a notifiable disease.
Research should be generously funded. We should try to find if people are already incubating the disease. The members of Seac who were in their posts before November 1995 should be asked to resign.
They should have known that a more cautious approach should have been taken. Optimism, finger-crossing and inactivity is unacceptable for a disease such as this.
The writer is consultant in medical microbiology at Burnley General Hospital.Reuse content