It has been suggested by a Swiss biophysicist that brain, spinal cord and offal from chickens, pigs and sheep should be discarded at slaughter, in the same way that cattle organs are now. It is thought these animals may be contaminated with the rogue prions implicated in the transmission of BSE to humans in the form of variant Creutzfeld Jakob Disease (vCJD). The same scientist claims he has evidence that transmission from chickens, pigs and sheep is as likely as it is from cattle.
It was only in December of last year that animal feed based on bovine meat and bone meal (MBM) was banned in Europe. Until then, chickens, pigs and sheep were fed MBM that could have been contaminated with BSE, and this meat was still entering the human food chain. Although transmission across species is still not well understood, it is likely to be linked to the structural biology of the prion. This makes NMR a useful tool for investigating normal prions, at least. Abnormal prions do not remain long enough in solution before aggregating and therefore this technique is not possible.
Prion specialists at St Mary's Hospital in London, published similar findings in the Proceedings of the National Academy of Sciences (PNAS) last August. The St Mary's team infected laboratory mice with a form of hamster scrapie and concluded that sheep, pigs and poultry could theoretically pass BSE to humans. However, transmission experiments are needed to confirm this assumption.
Reported by Sabine Louet for BioMedNet News.
12 March 2001