MAFF hears what it wants to hear

三月 29, 1996

By 1988, the ministry of agriculture, fisheries and food was aware of a serious crisis. Cases of Bovine Spongiform Encephalopathy or "mad cow" disease were confirmed from diverse locations in Britain. It was also known that the disease resembled transmissible spongiform encephalopathies in other mammals.

Indeed, the demonstration of experimental transfer of the infectious agent of BSE to mice was published in October 1988. [The risk was that it might affect humans in the form of Creutzfeldt-Jakob disease, a fatal brain disorder.] Predictably, the Government sought experts to advise on how to handle the problem. That committee was chaired by Sir Richard Southwood, the professor of zoology at Oxford. The other members were all distinguished in their own fields and had all provided the Government with helpful advice in the past.

But a number of members were retired, so had little contact with colleagues on a day-to-day basis. Amazingly, none of the committee members had published research on the spread of spongiform encephalopathies. Thus, much of the data relevant to BSE would have been provided by officials from the ministry.

It must be stressed that immediately Southwood considered the background information, he asked for a prohibition on refeeding cattle and other ruminants with proteins derived from their species. The ban came into force on July 18, 1988. But then, in my opinion, the committee went off the rails, as judged by the report published in February 1989. The first error was to blame the source of BSE on sheep scrapie (cattle had been fed the remains of a variety of animals, including cattle themselves and sheep, some infected with the disease scrapie).

This was convenient for ministers who would subsequently argue that since sheep scrapie does not infect man, and BSE is cattle scrapie, then there is no risk from the latter. It is now known that BSE is not derived from sheep scrapie, certainly not in the recent past. American research has shown calves exposed to sheep scrapie do not get BSE. Moreover, the infective agent that causes BSE is considerably more heat-resistant than that which causes scrapie.

The committee's next error was to estimate 17,000 to 20,000 cases of BSE in total, with no transfer of the infection between cattle or to calves. This contrasts with the actuality of 160,000 cases to date, with the occurrence of both vertical and horizontal transfer. But the most extraordinary conclusion by that committee was that BSE was in a "dead-end" host. Obviously, if this was the case, man was not vulnerable. A brave new biological concept was thus developed - that of a non-infectious infection. The Government was delighted. It could reassure the public that beef and milk were safe. It need not take the costly action needed to stamp out a serious infection in herds; such action would have had to include quarantine, cessation of breeding, slaughter and replenishment.

Because this action was not taken in 1988 or 1989, 80 per cent of dairy cows now are derived from an infected herd and curative action will have to be draconian. No doubt, the Government likes to receive generally reassuring opinions, certainly in the run-up to the next general election, but this is no way to sort out a very serious problem. We are now paying the price.

In the future we must develop scientific expertise to a sufficient extent to provide a reservoir of experts, wholly independent of government and industry, to provide sound, even if unpalatable, advice on a broad base.

I would like to end on a personal note, an experience that has helped provide insight into the way advisers to the Government are identified. Between 1986 and 1990, I sat on the Veterinary Products Committee that advises the minister on the use of drugs in animals.

In the early 1980s there had been considerable public unease that the overuse of antibiotics in, for example, chickens to increase their weight gain, might select resistant bacteria capable of causing serious human infections. Some of my previous published research had shown that human use of antibiotics, not animal use, was the main cause of resistance to antibiotics in human bacteria. Such a view would evidently help to sustain the use of antibiotics in broilers for commercial gain.

A civil servant told me that I had been carefully vetted for this view. This illustrates again that the Government and its civil servants do their best to hear the advice they want to receive, rather than what is right, certainly in the long term.

Richard Lacey is visiting professor of medical microbiology, Leeds University and a consultant microbiologist at Chapel Allerton Hospital. He has been warning of the risk to humans from BSE for seven years.

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