Human Form Of Mad Cow
Disease (CJD) Mystifies Doctors
By Patricia Reaney
LONDON (Reuters) - More than four years after British scientists discovered a link between ``mad cow'' disease (BSE) and its human equivalent, doctors are still mystified by the illness for which there is no treatment or cure.
Eighty-four people have been struck down by new variant Creutzfeldt-Jakob disease or vCJD. More than 70 have died and no one is sure how many other people may be harboring the disease.
Estimates of new infections range from hundreds to millions.
Scientists do not know how long the disease incubates in the body, the extent of exposure or if any resistant factors are involved. In short, they have no way of knowing who will get it or when.
Ministers in Britain's previous government are expected to take the brunt of criticism for their handling of the BSE crisis when the results of a long-awaited inquiry are made public on Thursday.
But Dr Steve Dealler, a British microbiologist and BSE expert, said although errors were made and more aggressive action should have been taken to curtail the public health crisis little could have been done for today's vCJD victims.
``There is nothing we could have done about the cases of vCJD we are seeing at the moment. What we could have done was not change the way cows were fed or organized things so that this kind of disease would not have appeared,'' he told Reuters.
Demand For Cheap Food
Scientists believe BSE was caused by feeding the carcasses of sheep infected with a related brain disease to cattle. Dealler said it dates back to World War Two when Britain was under pressure to increase output from its limited amount of land.
Both Dealler and Ray Bradley, a retired pathologist with the Veterinary Laboratory Agency where the first case of BSE was diagnosed, said vCJD sufferers would have been infected before the government imposed a ban on feeding animal remains to cattle.
``The cases we are seeing at the moment almost certainly would have been infected long before any ban could have come in or long before any action could have been taken,'' said Dealler.
The first case of BSE was identified in British cattle in 1986 and a decade later researchers linked it to vCJD.
``There is no doubt that it is the same form of BSE. It is BSE but how we caught it is another matter. It fits fairly well with diet but we are not sure why younger people, and not older ones, are going down with it. It's not clear exactly what the mode of transmission precisely is,'' according to Dealler.
Mutated Brain Protein Cause Of Disease
Most scientists are convinced that eating contaminated beef is the most likely mode of transmission.
Both diseases are caused by tiny mutated brain proteins called prions that are normally present in the brain and other tissues.
The illness develops when the proteins fold in an abnormal way. They multiply, clump up and cause the brain to become spongy and wither. Sufferers become confused, lose their coordination and slowly deteriorate and die.
Death usually occurs about a year to 18 months after the onset of symptoms. Cases are confirmed by a pathological exam after death.
``There is no treatment, no cure, no test,'' said Dealler, adding that scientists are now working on a diagnostic blood test.
But he said even if one is developed it will cause ethical dilemmas because a diagnosis means certain death.
Dealler believes a ``severe conflict of interest'' between the Department of Health and the Ministry of Agriculture, which was trying to protect the cattle industry, was behind the mishandling of the BSE crisis.
``After a while the Ministry of Agriculture got itself to such a point that it couldn't go back and say we were wrong. It had to cross its fingers and hope BSE wasn't going to infect humans,'' he added.
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