Late breaking news It now appears that there is a serous outbreak of BSE in France. It is now believed vCJD is caused by the transmission of BSE to humans. The evidence supporting this is that strain typing studies in both mice and primates, the disease pattern of BSE and vCJD, Feline Spongiform Encephalopathy (FSE), and TSE of exotic ruminants show a similar pattern but differing from those of Scrapie and sporadic CJD. Western blotting of the proteins are the same for BSE and vCJD, but the patterns for BSE and vCJD are different from those of other TSE such as sporadic CJD and iatrogenic CJD. Also, brain waves reading and histological patterns in the brain are different for vCJD and CJD. When transgenic mice are inoculated with the bovine prion gene from BSE cattle or inoculated with vCJD tissue, the same disease pattern and incubation period is obtained. BSE also has a different host range than Scrapies with the specie barriers in BSE being weaker. Unfortunately, when TSE crosses the species barrier the disease becomes stronger and more virulence, incubation time is shorter, there is an increase in the host range, and the disease has different properties. During 1990 to 1996, more cases of CJD have occurred in farmers who are known to have had cases of BSE on their farms. Two farmer's wives have also succumbed to CJD. However, no one has demonstrated a link between these cases and BSE. It has been identified that meat and bone meal was the responsible vector in which the disease was spread. Mandatory preventing the feeding of ruminant tissue to ruminant animals reduced the infection rate by 80%. Other changes are that SBO should not be used as agricultural fertilizer and that water treatment on sewer discharges will not inactivate prions.
It was first thought that the rendering process that had been modified in the United Kingdom using lower temperatures was the culprit but even earlier higher temperatures would not have been sufficient to inactivate the preon. By the time BSE was identified in England, it was likely that 50,000 cattle had been affected. It is also likely by this time that some human victims had been affected. To date (2000) no cattle in the U.S. have been identified with BSE and there has been an active search for the disease in suspected animals and "downers."
The question now becomes are we seeing the beginning of an epidemic caused by vCJD or only a few susceptible people involved? All the current (2000) victims of vCJD have a similar genetic code which probably makes them more susceptible to contracting the human form (vCJD) of BSE.
AMI (American Meat Institute). 2000. Inside AMI. Oct. 30. Pg. 2.
http://62.189.42.105/report/contents.htm. Full Inquiry Report.
http://62.189.42.105/report/volume1/execsum2.htm. The BSE Inquiry:The Report.
Nova. 1998. The Brain Eater, VCR Tape.
Ockerman, H.W. 1996. Facts and Speculation About Bovine Spongiform Encephalopathy (BSE). Dept. of Animal Sciences. Research and Reviews. The Ohio State University, Columbus, OH.