18-4 |
Diagnostics and detection of BSE |
D. MOMCILOVIC, Center for Veterinary Medicine, U.S. Food & Drug Administration, 7500 Standish Pl., HFV-226, Rockville, MD 20855 BSE is a chronic degenerative and debilitating disease of the central nervous system (CNS) in cattle. The disease is not curable but can be prevented. Years of research have failed to identify the precise mode of transmission of BSE, although epidemiological evidence suggests strongly that feed containing rendered mammalian materials from BSE-infected cattle, is the vehicle spreading the disease. Consequently, regulations that limit use of certain animal proteins in ruminant feed were introduced to reduce the risk of transmitting the disease. Reliable tests are needed to detect prohibited materials in feed and to diagnose BSE disease in tissues. Methods to detect prohibited animal protein in feed are not designed to detect the BSE agent in feed. Some food methods are designed specifically to detect CNS tissues, which are believed to contain the greatest level of infectivity. Diagnostic methods for BSE are designed to detect the disease process, or the presence of the abnormal prion protein, which is the marker for the disease, or both the disease process and the prion protein. Although BSE may be suspected ante mortem by physical exam, it can be confirmed only by post mortem examination using certain diagnostic methods. Considering the relatively fast pace by which scientific information on detection/diagnostics of BSE is becoming available, and the fact that it is not always simple to figure out whether a new test is pertinent to detection of prohibited material in feed or to diagnostics of BSE, the objective of this presentation is to review current testing methods and to draw the distinction between testing animal feed for prohibited ingredients and testing tissues for BSE.
Session 18, The prion diseases: Human health and food safety
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