London Observer Service
LONDON - Britain's "mad cow" disease epidemic was caused by a scientific experiment that went wrong, some experts believe.
The blunder has cost Britain $6.4 billion, claimed the lives of 43 people and triggered fears that the death toll could eventually reach several million.
Experts believe that hormones, taken from the brains of slaughterhouse carcasses, were injected into cows in a bid to create a new breed of super-cattle. But the experiment - carried out in the 1980s - backfired. The hormones, extracted from pituitary glands, were transmitted in an agent that spread mad cow disease and eventually infected humans as new variant Creutzfeldt-Jakob Disease (nvCJD).
Twenty years ago, a similar use of human growth hormone, extracted from the pituitary glands of cadavers and given to children with congenital dwarfism, was shown to have spread CJD among humans.
"The theory is simple," said Dr. Anne Maddocks, a retired senior medical scientist who specialized in infection control at St. Mary's Hospital in London. "The promiscuous use of pituitary hormones in cattle led to BSE in the same way that they led to CJD in humans. The timing of the deaths in cattle and humans who were exposed to pituitary hormones is very compelling."
Maddocks has spent a year investigating the theory, which overturns previous ideas that blamed the epidemic on changes in the preparation of sheep carcasses infected with the brain disease scrapie, which were fed to cattle.
Maddocks is backed by Malcolm Ferguson-Smith, an award-winning Cambridge University scientist on the government's mad cow disease inquiry team.
Evidence supplied separately by Joanna Wheatley, a former researcher and now an organic beef farmer, also supports the theory. Wheatley says abattoirs were selling pituitary glands to vets and researchers. Cows then got the disease through contaminated brain extract in their hormone injections. Infected cattle were "recycled" back into the national herd when carcasses were used in feed or bovine medicine.
The theory is also supported by David Brody, the lawyer acting for families of victims of the BSE-related nvCJD, who are suing the government. Brody also represents families of those who died from CJD after receiving growth hormone treatment.
"One has to take this theory very seriously indeed," he said. "There is a striking resonance to the timing of events and the thinking behind them, and the similarities suggest that serious questions need to be answered."
A spokesman for Ministry of Agriculture refused to be drawn: "It is a theory being considered, but it is only a theory."
Although the ban on British beef exports was lifted in Europe last week, specialists warn that nvCJD could still kill millions of people. Sir John Pattison, the chairman of the government's scientific advisory body on the disease, said it would take a decade to know the full impact of the crisis.
"We, as a population, are in deep trouble," he said. "That is why the range of possible numbers of variant CJD still goes from something not very different from the numbers we have at the moment to six- or seven-figure numbers."
His remarks led another panel member, David Pepper, to warn that the chance of such comments causing "alarm and despondency and maybe even worse are quite high."
In another sign that scientists are still in the dark over the disease, a new warning has been issued by John Collinge, another scientist advising the government, suggesting that people having their tonsils and appendix out are at risk of contracting nvCJD. This is because the disease has been found in these parts of the body and can be spread through surgical instruments,
he warns.
