| New evidence that thousands of Britons may be harbouring the human form of mad cow disease has emerged from government-funded research. Scientists who examined 12,674 stored appendix and tonsil samples said they had identified three bearing signs of the agent that causes variant CJD (vCJD). Applying the findings to the whole population, they estimate that about 3,800 people in the UK would test positive. Not all may be destined to die from the fatal brain disease, however. Scientists think the findings - which at first sight seem at odds with declining rates of vCJD - might indicate that people can carry the disease without developing symptoms. They would still be able to spread the disease to others via contaminated surgical instruments, blood transfusions or organ donation. Steps have already been taken to reduce the chances of such transmission as far as possible. But, while being careful not to exaggerate the implications, the scientists say their results should be taken seriously. Study leader Dr David Hilton, from the Department of Histopathology at Derriford Hospital, Plymouth, said: "Our findings need to be interpreted with caution, but cannot be discounted." The research, published in the Journal of Pathology, involved examining thousands of appendix and tonsil samples removed during routine operations and stored at hospitals. Most were from people aged 20 to 29 who belonged to the highest risk group for vCJD. |