prions as well, but I'm not certain.
Here's something from the CDC:
<Is BSE a foodborne hazard in the United States?
Strong evidence indicates that BSE has been transmitted to humans primarily in the United Kingdom, causing a variant form of Creutzfeldt-Jakob disease (vCJD). In the United Kingdom, where over 1 million cattle may have been infected with BSE, a substantial species barrier appears to protect humans from widespread illness. As of December 1, 2003, a total of 153 vCJD cases had been reported worldwide; of these, 143 cases had occurred in the United Kingdom. The risk to human health from BSE in the United States is extremely low.>
<What is the variant form of CJD that the experts in the United Kingdom believe might be related to the BSE outbreak in cattle?
In contrast to the classic form of CJD, the variant form in the United Kingdom predominantly affects younger persons (median age at death around 29 years) and has atypical clinical features. These atypical features include prominent psychiatric or sensory symptoms at the time of clinical presentation or early in the course of the illness, delayed onset of neurologic abnormalities, duration of illness of at least 6 months, and a diffusely abnormal non-diagnostic electroencephalogram.>
http://www.cdc.gov/ncidod/diseases/cjd/bse_cjd_qa.htm