010146 BSE Screening Test Is Accurate, Study SaysJanuary 24, 2001London - French scientists said that results of a rapid test to detect mad cow disease show it is effective and should help ensure that infected animals do not enter the food chain. As more cases of the brain-wasting disease are reported around Europe and fears grow that beef infected with bovine spongiform encephalopathy is making its way to dinner tables, researchers said the test is accurate and as quick as other BSE tests. “Routine application of the test should help eliminate previously undiagnosed BSE-affected animals from the food chain and provide tighter epidemiological monitoring of the BSE epidemic,” Jean-Philippe Deslys, of the French Atomic Energy Commission (CEA), said in the report in the journal Nature. The two-step biochemical test is manufactured by U.S. medical products company Bio-Rad Life Sciences Laboratories Inc. “By eliminating all the cows found positive (with BSE) theoretically this test can guarantee the elimination of all the animals dangerous for humans,” Deslys said in a telephone interview. But New Scientist magazine said on Wednesday the results of the study are confusing because veterinary authorities across the European Union have found the test throws up false positive results. “Belgian abattoirs have recorded 36 positives using the Bio-Rad test, but only two have been confirmed as BSE by sensitive microscopic observation, according to the Belgian food safety agency,” the magazine said. The test detects the abnormal protease-resistant form of the prion protein, which causes the disease, in the brain tissue of dead cattle. Deslys said results are ready within five hours. No Test For Live Animals Yet The test is one of several approved by the European Commission for testing slaughtered cattle over the age of 30 months for BSE. European officials are now questioning whether the age limit should be lowered after BSE was detected in an animal under 30 months. They were also considering a curb on the sale of T-bone steaks following concerns that meat recovered mechanically from the vertebral column and untreated animal fats could present a BSE risk. Although researchers are trying to develop a test for live animals, there is none available at the moment. Deslys said the Bio-Rad test was as effective as the conventional mouse test, in which brain tissue from cattle is injected into mice to see if they develop the disease. But unlike the mouse test, which is impractical for mass screening, Deslys said the Bio-Rad test can be automated and it is relatively inexpensive. But he said more work is needed to test its sensitivity in routine BSE surveillance. BSE first broke out in British herds in 1986. Scientists suspect it was caused by feeding carcasses of sheep that died from a related brain disease to cattle. Some researchers believe it could have occurred spontaneously in cattle.
E-mail: sflanagan@sprintmail.com |
