vCJD cases 'on the increase'

The final total of deaths could be as high as 140,000

Scientists have reported a sharp increase in the number of cases of vCJD - the human form of "mad cow disease".

They also say that people living in the north of England and Scotland are more than twice as likely to get the disease as those in the south.

The disease has now claimed the lives of more than 100 people in the UK, and scientists say its incidence increased by 20% last year.

Estimates of the final total of cases expected in the UK range from a few hundred to 140,000.

There have been 15 confirmed cases so far this year, according to Department of Health figures.

Professor James Ironside says the number of cases and deaths from vCJD are up by 20%

Professor James Ironside, of the vCJD Surveillance Unit at Edinburgh University, told BBC Radio 4's Today programme on Wednesday it was difficult to tell how the disease would grow in the future.

"Because of the uncertainties associated with the disease, the unknown incubation period, genetic factors that are probably associated with different susceptibility - it makes modelling the future very difficult," he said.

He also said there was no clear explanation for why people in the north should be more susceptible to the disease.

One possibility was that genetic factors meant people in the north were more susceptible to the disease, he said.

Another, which Professor Ironside thought was more likely, was that northerners have had more exposure to the disease, because they were more likely to have eaten more pies and burgers containing low-grade meat.

Mechanically recovered meat

It is impossible to check this theory unless the food industry reveals which of its products contained low-grade meat.

The Spongiform Encephalopathy Advisory Committee (Seac) has spent five years asking food companies how much "mechanically recovered meat" (MRM) was used in the past, as they believe this type carries the most risk of passing on BSE.

MRM is meat residue which is left on the carcass after all the prime cuts have been removed.

However, Seac says it has been "continually thwarted" in its efforts to extract information from the industry.

FSA doubts

But last month the Food Standards Agency (FSA) launched a new investigation to try to extract information from the industry.

However, Gillian Turner, of the CJD Support Network, said she had serious doubts over the role of the FSA.

She said:"Our concern is that the FSA have enough teeth to enforce the endeavour to get information.

"This is really why there is a need for openness from every agency so that we can get to the bottom of what's happening.

"We need constant vigilance on the cases and it's so very important that more information is given so we can gain more knowledge of CJD and try to be ready if there is an explosion in the cases."

But Bill Jermey, President of the Meat Manufacturers' Association, told the BBC that while they wished to co-operate, information on where exactly MRM had been supplied was not available.

Professor Ironside said the origins of vCJD were still a mystery to scientists.

He said he favoured the theory which was that cattle had been fed carcasses of sheep with a mutated form of the disease scrapie.

The scientific reports into the possible extent of vCJD have been welcomed by the Save British Science Society (SBS).

Its director Dr Peter Cotgreave said: "It wasn't until we had an expensive inquiry that the public discovered that the Chief Medical Officer had been trying to warn ministers, let alone the public, of serious risks about BSE.

"Pen-pushers in the old Ministry of Agriculture told him that it was 'a step too far' and blocked him."