BSE inquiry delivers report as scientists raise fresh concerns about "mad cow disease"

By Paul Mitchell
3 October 2000

The inquiry into the BSE (Bovine Spongiform Encephalopathy) crisis set up by Labour shortly after coming to office in 1997 sent its final report back to the government yesterday. It covers the period from the first recognised outbreak of “mad cow disease” in the mid-1980s up to March 20 1996—when the previous Tory government first admitted a direct link between BSE in cattle and a new variation of Creutzfeldt-Jakob disease (vCJD), the brain-wasting disorder in humans.

The 16-volume report took two years to compile and includes evidence and testimony from more than 1,000 witnesses, including the families of Human BSE victims. It is believed that the report, which will be made public later in October, concludes that former ministers and officials should have acted with a “greater sense of urgency”. An official quoted in the Daily Telegraph expressed the real thinking in government and civil service circles, “If you were being darkly cynical, you could say the wait-and-see policy over BSE was a qualified success. The dead still number under three figures—a bit of a narrow squeak, admittedly, but hardly the calamity it might have been”.

Last month, scientists raised new concerns about vCJD. Seventy-five people have already died in Britain and another seven people are dying from the illness, probably caused by eating beef infected with BSE. On Thursday last week, a fifth person died of suspected vCJD in a small area of Leicestershire. The Leicestershire CJD "cluster" was first reported in November 1998, after it claimed three lives within 12 weeks.

Instances of BSE in Britain still far outstrip those anywhere else. There have been more than 177,000 cases, with nearly 780 confirmed so far this year. By contrast, Ireland has had a total of 489 BSE cases, Portugal nearly 350 and Switzerland 365. But BSE could be on the increase in France. The recent discovery of an infected cow in the Rhone region brings the total number of cases this year to over 40, up from 31 in 1999. Unlike Britain, French policy is to slaughter the entire herd whenever a proven case of BSE is discovered. There have been two cases of human BSE in France, and one in Ireland and Italy.

Originally, it was thought that the infectious BSE agent (a prion protein) was contained only in certain tissues such as the spinal cord, brain and other organs. New research suggests that blood may also carry the disease and that it can transfer between different species more easily than previously thought.

Scientists at the Institute of Animal Health in England have shown that BSE-free sheep developed the disease after being injected with blood from infected sheep. Their report warns, “Blood donated by symptom-free vCJD-infected humans may represent a risk of vCJD infection among humans.” It has been discovered that seven people who have died from vCJD were blood donors whilst they were incubating the disease.

Earlier this year a baby girl suffering brain damage and growing at half the normal rate lost her mother who suffered from vCJD, suggesting transmission by blood was the cause. Eight cows have contracted BSE from the continued use of blood in animal feed.

The Australian government has followed the United States by banning the use of blood from travellers from the UK. Last year the Labour government ordered hospitals to remove all white cells from blood donated in Britain. It said the risk was only theoretical and there was no evidence that vCJD had “ever been transmitted to humans through blood transfusion or blood products”. However, because there have been years of denials—from the claim that cows were a “dead-end host” for BSE which could not cross over to humans, to claims that only nervous tissue was infective—there have been few experiments to look for wider evidence, such as in blood.

Last year the Department of Health issued guidelines to all health professionals including dentists for the “thorough cleaning and sterilisation” of equipment, but the prion protein that causes the disease is virtually indestructible. Only now is the government considering the wider use of disposable surgical instruments currently restricted to tonsil, appendix and brain operations.

That these measures are insufficient is suggested by new research showing the procedure to remove white blood cells is imperfect and red blood cells could also transmit the disease.

Other evidence has emerged from Professor John Collinge's team at St Mary's Hospital in London. Whilst it is known that animals may be infected with BSE do not show symptoms for years, Collinge believes that animal species can act as silent carriers without ever showing symptoms. He said, “We should not assume that just because one species appears resistant to a strain of prions that they do not silently carry the infection.” It could be the reason why only one or two cows in a herd die; the others might have a silent form of the disease. Collinge said there could be a silent form in humans too and suggested “current definitions of the species barrier... need to be fundamentally reassessed”. The team's new findings imply there are silent forms of BSE in sheep, pigs, chickens and other animals used for human consumption. According to the Ministry of Agriculture, “We believe the safeguards we have in place at the moment are adequate to deal with the issues Professor Collinge raises”. The head of the new Food Safety Agency (FSA), Sir John Krebs, said no further reassurances were necessary.

Professor Stanley Prusiner, the discover of the prion form of protein, also believes that BSE occurs at low levels in sheep but it is masked by scrapie, a similar form of spongiform encephalopathy that has existed for hundreds of years without apparently affecting humans. Prusiner says “BSE prions in sheep may thus have been there all the time at very low levels that pose no significant risk to humans but unusual circumstances might have allowed them to spread either through the sheep or cattle populations and accumulate to levels hazardous to humans.”

It is much more difficult to remove the potentially infected material in sheep than in cattle, casting doubts over the future of sheep farming in Britain. The government's response is to call for research into breeding BSE and scrapie-resistant sheep. Early in the BSE crisis Professor Richard Lacey, an expert in diseases like BSE, was hounded from his job for suggesting all livestock in Britain should be destroyed to eradicate the danger of the disease to humans.

Government policy, whether under the Conservatives or Labour, is directed to maintaining confidence in the British meat industry. It has asked the FSA to consider “at what point in the future it might be appropriate to relax the rules” surrounding the use of cattle and feedstuff.

Consequently, it is proposing to relax some of the existing controls, e.g. the use of intestines and thymuses from young calves. Cows' blood is still routinely used as a component of cattle feed.

When it comes to the families of those who have died from vCJD, the government has a different attitude. The Guardian newspaper reports that the government will fight any claims for compensation in the courts.