The spread of the human form of mad cow disease in Britain may not be as extensive as was first thought.

Research published by the Royal Society suggests that a large epidemic of variant Creutzfeldt Jakob disease is unlikely, as scientists reduced their previous estimates of future cases and deaths from 50,000 to 7,000.

The new estimates, which are based on the number of vCJD cases before the end of 2001, do not include figures from 2002 that show a decrease in deaths from the disease, meaning the true figure for future cases may be even lower.

By the end of 2001, 113 cases of vCJD, a degenerative and incurable brain disease linked to eating meat infected with bovine spongiform encephalopathy (BSE), had been diagnosed in Britain. Due to factors such as the long incubation period of the disease, scientists have had difficulty predicting how many people will be diagnosed with the disease in the future.