Bovine Spongiform Encephalopathy in Japan: History and Recent Studies on Oxidative Stress in Prion Diseases

Abstract

With respect to BSE and vCJD, compliance with the following three rules should strictly be observed: (i) Identification and destruction of all clinically affected cattle; (ii) destruction of all mammalian proteins used in feeding ruminant livestock; and (iii) destruction of all high-risk tissues for use in human consumption. Plugging "loopholes" of these rules is the essential factor required to accomplish the task more efficiently. Although compliance with the basic rules is an important issue, global evidence has demonstrated that compliance is imperfect. An important Japanese response to the emergence of this disease was the establishment of independent scientific committees to formulate strategies for adopting relevant disease and control countermeasures. These were the Food Safety Commission (FSC) of the Japanese Government Cabinet Office, and the Prion Expert Committee in the FSC to persistently provide independent advice on said strategies. In addition, the Expert Committee on the Impact of Cattle-Testing assessed the risk of human exposure to BSE agents in Japan. The screening test employed for detection of the expected fraction of BSE-infected cattle destined for slaughter yielded 20%, even if all slaughtered cattle were tested by the ELISA and Western blot. Provided that the removal of specific risk-materials was conducted properly, the discrepancy in changing the age limit to over 20 months of age was negligible for testing beef safety. Scrapie in sheep has been documented in the 18th century in the United Kingdom.

Neuroanatomical Distribution of Disease-Associated Prion Protein in Cases of Bovine Spongiform Encephalopathy Detected by Fallen Stock Surveillance in Japan

“…The first case of BSE in Japan was reported in September 2001 [16] and the last one was confirmed in January 2009. All obsolete cattle obex-level samples from bovine > 20 months of age were examined using a specific enzyme-linked immunosorbent assay (ELISA) against prion protein (PrP) for BSE at a livestock hygiene service by the active fallen stock surveillance program in Japan [19,35]. At the time of writing, 14 BSE cases (13 Holstein dairy cows 48-102 months of age and 1 Japanese Black beef cow 89 months of age) were confirmed by western blotting analysis as well as histopathological and immunohistochemical examinations at our laboratory.…”

Review of studies that have used knockout mice to assess normal function of prion protein under immunological or pathophysiological stress

“…Prion diseases, such as bovine spongiform encephalopathy, scrapie and Creutzfeldt‐Jakob disease (CJD), belong to a category of transmissible diseases that produce similar pathological findings in the central nervous system (CNS); these include neuronal degeneration, vacuolation and gliosis . In addition, these diseases are fatal, manifesting as infectious, sporadic or genetic diseases in both animals and humans .…”

Bovine Spongiform Encephalopathy – A Review from the Perspective of Food Safety

“…The first BSE case identified in Japan was a cow slaughtered in August 2001 130,131) . A series of control measures with binding legal force were taken later in 2001, including a ban on the import of MBM, a ban on the use of MBM for feed of all animals (designated as complete feed ban), the burning of specific risk materials (SRM) (the head excluding tongue and cheek meat; the spinal cord; the ileum of 2 meters long from its connection with the cecum).…”