THEORY: BSE SPREAD FROM CJD HUMANS TO CATTLE?

BBC: The first cases of BSE or "mad cow disease" could have been caused by animal feed contaminated with human remains, says a controversial theory. It proposes that some raw materials for fertiliser and feed imported from the Indian subcontinent in the 60s and 70s contained human bones and soft tissue. ... The UK imported hundreds of thousands of tonnes of whole bones, crushed bones and carcass parts in the 1960s and 1970s to make fertiliser as well as meat and bone meal feed. Nearly 50% came from Bangladesh, India and Pakistan, where gathering large bones and carcasses from the countryside and from rivers is an established local trade. ... Human remains have been described in material delivered to processing mills. And during the 1960s, human material was confirmed in consignments of bones shipped into French docks from Asia. A spokesman for the Department for Environment Food and Rural Affairs (Defra) said it went along with the findings of a 2001 report into the origin of BSE, where a favoured hypothesis was that BSE had its origins with scrapie. But the spokesman said the department was open minded about new findings. ... only a tiny amount of contaminated brain tissue is needed to transmit human CJD to nonhuman primates in the lab. On the other hand, nothing is known about the transmission of human prion diseases to cattle. It was shown in the 1980s that prion proteins could survive the entire chain of processes leading to the production of animal feed in an infectious form. The feeding of mammalian meat and bone meal to farm animals has been banned since 1996. Yet sporadic cases of BSE have occurred in the UK and in Europe, where regulations were also tightened, since the ban. These cases remain unexplained.

Fascinating.