Mad Cows and Englishmen - Michaelmass Madness 29 September

On this day, the 29 September (Michaelmass Day) in 1997 British scientists established a link between a human brain disease and one found in cows. The stunning conclusion of two major studies was that a new version of Creutzfeldt-Jacob disease (vCJD), was caused by eating BSE-infected meat. At that time 21 people in the UK were suffering from the disease. I have written elsewhere on the early causes of Bovine Spongiform Encephalopathy (BSE) or "mad cow disease" and the studies proved that the two diseases were caused by the same infectious protein. It was also discovered that the risk of humans becoming infected with vCJD depended on their having a genetic makeup that included a combination of genes called "M-M".

On this day in 1997 there had already been 18 human deaths from vCJD. Two months after these findings, a selective cull of cattle at most risk to the disease was started, and a 'beef on the bone' ban introduced. Since then there have been 139 deaths due to vCJD and there are 5 people who are still alive who are known to be dying of the illness. There are still an unknown number of people who may be incubating the disease - conceivably as many as the 32% of the population of Britain (about 19 million people) who have the "M-M" gene combination - but numbers have been declining since a peak in 2000. Hundreds of thousands of cattle have been culled to try and eradicate the disease.