Bone meal fertilizer and vCJD?
First, some vocabulary:
vCJD - variant Creutzfeldt-Jakob Disease - the human form of 'mad cow disease' which is transmitted by eating brain or nerve tissue from infected animals. It is always fatal; no exceptions.
BSE - Bovine spongiform encephalopathy - mad cow disease (the bovine form of the disease)
Scrapie - a similar disease in sheep
Chronic wasting disease - a similar disease in deer
Kuru - a similar disease that occurred in one particular tribe in New Guinea; this tribe was unusual in that they were cannibals but ate their dead relatives. (Cannibals generally eat dead enemies only.) Only the women and children ate the dead relatives. Only the women and children got the disease too.
Prion - all these diseases are thought to be to be transmitted by 'prions' which are a type of protein.  Prions can survive being autoclaved, heated to extremely high temperatures (way beyond what cooking would ever produce). In fact, we don't yet know any way to kill them.
Transmissible spongiform encephalopathy - all these diseases together are classed as 'transmissible spongiform encephalopathies'.
The BSE problem first surfaced in the UK in cows (1986) and later young people started dying of CJD. It is thought to have crossed into cows because they were fed on animal tissue, including tissue from sheep who had scrapie.
I read about BSE then in the news (as did everyone else), and I wondered about the safety of bone meal fertilizer.
But I didn't have any evidence then that bone meal fertilizer could *possibly* transmit vCJD. I wouldn't use it - that's for sure. But that's really not enough to send a caution about bone meal to other people. For that I needed to be able to connect the dots.
Since the British problem surfaced, there have been several cases of BSE in North America: 'As of August 23, twelve cases of BSE have been identified in North America. Of these twelve cases, three were identified in the U.S. and nine in Canada.' 
Then recently, I was doing some research on the hazards of wood smoke. I found 'Some of the smallest fine particles can go deep into the lungs and can even pass through the lungs into the bloodstream'.  Ah hah - here's the pathway by which bone meal could possibly transmit vCJD.
Bone meal, I now discover, is made from the bone and tissues of 'downer' cattle: cattle too sick to walk to the point at which they are killed in a slaughterhouse. 
I was reading a book yesterday entitled 'Deadly Feasts' by Richard Rhodes.  Rhodes tells the story of how the cause of kuru (the New Guinea cannibal disease) was eventually discovered and how its connection with BSE (and the other similar diseases) was tracked down. Many medical researchers were involved, of course, but the person probably more responsible for solving the mystery than anyone else was an American medical researcher named D. Carlton Gajdusek. Gajdusek won a Nobel prize for his work.
At the end of the book are the following paragraphs:
"You know the bone meal that people use on their roses?" Gajdusek asked me then. "It's made from downer cattle. Ground extremely fine. The instructions on the bag warn you not to open it in a closed room. Gets up your nose." The Nobel-laureate virologist who knows more than anyone else
in the world about transmissible spongiform encephalopathy looked at me meaningfully.
"Do you use bone meal on your roses?"
I told him I did.
He nodded. "I wouldn't if I were you."
This is good enough for me. When a Nobel laureate advises against something related to his own field of study, I tend to listen. The dots are connected now.
So I not would advise that bone meal fertilizer be used: not on edible plants, and not on any other plants either. There are plenty of other fertilizers that will do the job.
 'Deadly Feasts', Richard Rhodes, 1997, Simon & Schuster, New York, p. 242.