Scientists baffled by mystery of new BSE case

Mad cow disease may be spreading through the country by previously unknown means, the Government's chief adviser on the human form of the disease said yesterday.

Professor Peter Smith, acting chairman of the Government's BSE advisory committee, Seac, was commenting on the discovery of a new case in a cow born after the introduction of tough controls to eradicate the disease. The cow's mother, or dam, was not infected.

The case raises fears voiced by scientific critics of the Government's approach to BSE that the disease may be spreading from cow to cow as well as from mother to calf.

This would raise the possibility that many of Britain's pastures are infected with the deadly prions that cause BSE.

An investigation to establish the origin of the infection will be carried out by the State Veterinary Service .

The cow, understood to be part of a Friesian dairy herd in Somerset, was born on 27 May 1997. This was nearly 10 months after 1 August 1996, the date by which extra control measures on animal feed containing mammalian meat and bone meal had been fully implemented.

It is only the second time BSE has been confirmed in a cow born after that date, although experts had predicted that there would be a small number of such cases. They have estimated that there will be a total of 17 reported cases by the end of this year.

The routes of possible transmission include feed carried over from before 1 August 1996 and infection from the cow's mother.

However, Professor Smith said the latest case is a matter of particular concern to Seac because the cow's mother did not have the disease.

"There are two things that have to be considered," he said. "One is whether there is some failing in the feed ban. That would be of some concern, because this is 10 months after we think the feed ban should have been watertight.

"The other possibility is that there is a third way of transmission. We know about feed transmission and we know about transmission from dam to calf.

"It is possible, and we can't exclude the possibility completely, that there is some other low-level form of transmission through which a case like this might arise."

Animal Health Minister Elliot Morley moved to reassure the public that the discovery poses no health threat. "We do not yet know the epidemiological significance of this case but the independent Food Standards Agency advises that there are no implications for food safety," he said.

"It does not change in any way our view that we have the toughest rules in place to protect public health and to eradicate the disease."

The cow confirmed as having BSE was aged 48 months when it was slaughtered. It would not have entered the human food chain because of the rule that prevents the sale for human consumption of meat from animals aged over 30 months.

The overall BSE epidemic continues to decline, with 1,311 BSE cases confirmed during 2000, 42 per cent lower than in 1999.

Speaking yesterday Margaret Beckett, the new Secretary of State for the Environment, Food and Rural Affairs, said that the foot and mouth crisis is an opportunity for regeneration of the farming industry.

Mrs Beckett promised a "culture of co-operation and openness" in her new department, which was created by the Prime Minister, Tony Blair, last Friday to replace the much-criticised Ministry of Agriculture, Fisheries and Food.