Is BSE meat safe to identify?
So far, beef did not just go over the counter if the cows had obviously suffered from the mad cow disease BSE: if they wavered or behaved strangely. This is not a true health protection for the consumer, because beef is - at least as animal feed - most infectious in the months before the disease breaks open, according to the finding of Neil Ferguson of the University of Oxford. So far, one could not recognize this disease stage in cattle. The solution to the problem: Tests to detect the pathogenic prions directly in the meat. Three such tests have since passed an EU test and may be used:
- The most reliable: The rapid test Prionics Check of the Swiss company Prionics. According to research director Dr. Bruno Oesch were immediately marked with him all samples immediately right. It costs about 95 marks per submitted brain sample and lasts about eight hours.
- The most sensitive: The test of the French Commission de l'Energie Atomique (CEA) at Gif sur Yvette Cedex. It still reacts at lower prion concentrations than the others.
- The fastest: The test of the Irish company Enfer Scientific from Newbridge in Kildare. It lasts four hours and costs about 57 marks per sample.
All these very simple Laor investigations can detect the dangerous prions already six months before the first clinical symptoms of mad cow disease. In Switzerland, since last year, all cattle must be tested, which behave in any way strange, lose weight or get sick. In slaughterhouse practice, the procedure is as follows: For the BSE test of the Swiss company Prionics, the veterinarian probes the slaughtered cattle in the transition from the spinal cord to the brain stem and takes a tissue sample. In this brain region, the pathogenic prions occur first and in high concentration. The veterinarians test the sample in a so-called Western blot with color-coded antibodies. If the blot shows the prominent spot of the prion, the official veterinarians seize the carcass and have it destroyed.
In Germany, such tests are not yet required, although EU food safety commissioner David Byrne urges Member States to do so. Since April this year, Bovina has been offering the Swiss BSE test under license for German slaughterers. As a trailblazer, the butcher Rainer summer near Heilbronn can test his slaughtered cattle - an action that led to indignant protests among his colleagues: Beef from Baden-Württemberg is safe and the test only expensive and superfluous, announced the competent buttocks. However, this claim has not yet been verified by Butcher Sommer. So far his findings are "negative". Fortunately, the commissioned laboratory found no prions in the slaughtered cows.
Undeterred, the researchers are working on even more sensitive tests, because the existing methods are only useful in animals that are older than 30 months, since only then enough disease-causing prions may have formed. Scientists led by the molecular biologist from Mainz, Werner Müller, and the American researcher Mary Jo Schmerr have now developed simpler tests in which the prions can be detected in the blood or cerebro-spinal fluid of cattle. But they have not been officially tested for reliability. display
bdw conclusion: The tests previously approved by the EU can only be used after slaughter and only in older animals. They increase consumer safety, but they do not provide complete protection, as they still do not know how infectious beef is from more recently infected animals.
Is there healthy meat from sick animals?
Prions are mostly in the nerves. The BSE agent is thus particularly in the brain and reaches there always the highest concentration. But also the spinal cord, internal organs and muscle meat are crossed by nerves. The British BSE expert John Collinge of Imperial College in London therefore suggests that muscle meat is much more infectious than one would expect. In addition, the prions can emerge from the brain when slaughtering: The veterinarian Haluk Anil from the University of Bristol found that after the bolt shot into the skull, the heart continues to beat for a while and so brain tissue is transported through the injured vascular system in the body. When dissecting the animal can also highly infectious brain and nerve tissue come into contact with the supposedly harmless muscle meat.
Bdw conclusion: BSE pathogens can occur in any part of the animal - albeit in low concentrations. Whether there are enough to infect a human, you do not know.
Links about BSE
- Keep your eyes open while buying beef. What do the labels mean? Where are the hooks? http://www.wdr.de/tv/markt/archiv/00/0522_1.html
- MadCow Page - Latest news and press releases on BSE http://mad-cow.org
- Prion Picture Gallery - What do prion molecules look like? http://www.mad-cow.org/~tom/prion_structure_folder/gallery.html
- The Prionics BSE test, technical description and a wealth of references http://www.prionics.ch
- Reports from the British BSE Inquiry Committee http://www.bse.org.uk === Thomas Willke