A government-backed study carried out at Cambridge University by researcher Gabriel Horn indicates that scrapie may have caused the outbreak of the mad cow disease BSE (bovine spongiform encephalopathy) and vCJD, which has claimed more than 100 lives since the late 1980s.

It is believed scrapie-infected sheep meat and bone meal (MBM) may have been fed to cattle.

Usually afflicting sheep, scrapie is not harmful to humans, but once present in cows it could have ‘triggered’ the development of BSE, claimed a Reuters report published yesterday [19 July]. The relatively high proportion of sheep in the UK, compared to cattle, compounded by a high incidence of scrapie, probably means that the UK’s meat-based animal feed contained a high level of scrapie-contaminated material.

It is not clear quite how the scrapie-infected feed could then trigger the development of BSE, but scientists indicate a strong link.

As the Reuters report claims, scientists have played down views that meat-based feed was not the only culprit in spreading mad cow disease. “The evidence is very strong that the spread of BSE to the point at which it became an epidemic arose through the use of meat and bone meal…in cattle feed,” the authors write.

The UK yesterday announced plans to step up efforts to eradicate scrapie in the national flock.