BSE carriers may pass it on unknowingly

LONDON, August 29 (SPIS MedWire). Animals could be carriers of BSE without showing any symptoms, according to a report in this week's Proceedings of the National Academy of Sciences. This raises fears that far more cows could be contaminated with the disease than originally thought, and may have entered the food chain by not falling ill. Scientists at St Mary's Hospital, London, were investigating the species barrier associated with the disease by injecting infected prions from hamsters into mice. Mice have always been thought to have an effective barrier. However, although they showed no symptoms of the disease they had high levels of potentially lethal abnormal prions in their brains. Professor Collinge, who led the study, said, "This undermines a lot of our confidence in the species barrier. It suggests that it is possible to suffer from sub-clinical forms of these diseases." Members of the Spongiform Encephalopathy Advisory Committee (SEAC) ...