NR AOEC
AU Brown,P.
TI The jury is still out
QU British Medical Journal 1995 Nov 25; 311(7017): 1416
IA http://bmj.bmjjournals.com/cgi/content/full/311/7017/1416
PT Editorial
VT
Creutzfeldt-Jakob disease has now been identified in four farmers and two adolescents in Britain, where its bovine spongiform counterpart has been epidemic for the past several years. Is there a connection? This question is being discussed by many different groups according to pre-existing biases and professional goals as might be expected for so controversial and potentially explosive a topic. The media has in the main sounded alarm bells because its goal is to produce an exciting story; the government has taken a low key, cautious approach because its goal is to prevent unwarranted panic; and medical science has been somewhat unpredictably divided in its evaluation, depending at least in part on individuals' distaste or flair for publicity.
In fact, no one can yet say with any confidence whether these cases of Creutzfeldt-Jakob disease in adolescents and farmers are the result of infection with bovine spongiform encephalopathy. In favour of the idea is the fact that so called sporadic Creutzfeldt-Jakob disease is typically a disease of late middle age, with only a handful of cases in people aged under 25; the disease would, however, be expected to occur in a more uniform age distribution if the source of infection was ingestion of cattle products, which explains the concern about "back-to-back" cases in young people. With respect to the four farmers, it is also true that each had at least one infected cow in his herd, raising the possibility of contact infection from the cows or even inhalant infection from the contaminated meat and bone meal feed that caused their illness.
Against the idea is the fact that adolescent Creutzfeldt-Jakob disease has occurred at times and places that virtually exclude the possibility of infection with bovine spongiform encephalopathy and that farmers have died of Creutzfeldt-Jakob disease m countries where bovine spongiform encephalopathy does not occur. It is also notable that the type of illness experienced by all six of the patients was typical of sporadic disease, rather than the predominantly cerebellar illness seen in patients infected peripherally from an external source such as contaminated pituitary hormones.
Statistical analysis will not yet be helpful in our evaluation of these cases, even if the observed occurrence can be shown to exceed significantly the expected occurrence in adolescents and farmers, because the power of statistics when dealing with so few cases is not compelling. In due time, however, statistics will provide the most important evidence for or against an association between Creutzfeldt-Jakob disease and bovine spongiform encephalopathy, as it is most unlikely that infection with bovine spongiform encephalopathy will ever be proved to have caused any individual case of Creutzfeldt-Jakob disease (for example, in someone who ate brain from a cow shown to have died of bovine spongiform encephalopathy). It is therefore crucial that the ongoing surveillance programme of Creutzfeldt-Jakob disease in Britain, in cooperation with similar programmes in other European countries, is sustained for at least several more years if an association between Creutzfeldt-Jakob disease and bovine spongiform encephalopathy is ever to be properly assessed.
Finally, there does not seem to be any need for new governmental hearings, committee meetings, or parliamentary debates about what more might be done because the precautions taken some years ago to eliminate potentially infectious products from commercial distribution were both logical and thorough. We are left looking at possible present consequences of past events over which we now have no control, and we can only hope that the affair will be happily resolved. At least we do not have to face the spectre of reparative legal proceedings, which in this case would amount to a class action suit for anxiety brought by the entire British population against its own government.
ZR 0 Zitate
AD Paul Brown (pwb@codon.nih.gov), Medical director United States Public Health Service, Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
SP englisch
OR Prion-Krankheiten 2