"The inflamed mammary glands of sheep have been found to contain protein particles that cause scrapie, a sickness similar to mad cow disease. This suggests that the suspect proteins, called prions, may also be present in the milk of infected animals.
"If prions exist in the milk of cows infected with both an inflammatory illness and mad cow disease, formally known as bovine spongiform encephalopathy (BSE), this raises concerns for human health. Consumption of prion-contaminated meat from cows with BSE is believed to cause the fatal variant Creutzfeldt-Jakob disease (vCJD) in people; so might contaminated milk.
"Adriano Aguzzi, the lead researcher on the study, has not detected prions in milk itself, because it is difficult to analyse for the abnormal proteins. But he says he expects to find them."
Enter Adriano Aguzzi into the PubMed search engine. You'll get 73 citations. If you make the entry in the standard format, i.e. Aguzzi A, you'll get 334 citations.
Something is happening with prion proteins that we don't understand yet. Lately, I'm more interested in Bastian's spiroplasma hypothesis.
Check out this thread.