A cluster of BSE is being investigated by scientists who fear that contaminated feed is still being given to British cattle, nearly 10 years after it was banned.
The cluster involving three young cows born long after the 1996 ban on contaminated feed is believed to have been found on a dairy farm in England. It is only the second such cluster of young BSE cases.
The first occurred on a farm in Wales and it too involved three young cattle that were born many years after the Government banned all animal feed that could be contaminated with BSE. Scientists said the occurrence of a second cluster of BSE in young cattle strongly suggested that the cases were not a statistical fluke and that contaminated feed had caused the outbreaks.
So far there have been 106 confirmed cases of BSE in cattle born since the 1996 "reinforced feed ban" after which, in theory, no newborn calf should have been exposed to the infectious agent responsible for the brain-wasting disease.
The ban involved the blanket prohibition on cattle feed made from mammalian protein, which is thought to have caused an epidemic of more than 150,000 confirmed cases of BSE since the 1980s.
But out of a total of 85 confirmed cases of BSE reported this year, 13 of them were in cattle born after the 1996 feed ban, which should have eliminated the possibility of new infections in Britain. Eliminating contaminated cattle feed from Britain was considered essential to the total eradication of BSE, which crossed into the human food chain to cause 156 cases of variant Creutzfelt-Jakob disease (vCJD), the lethal brain disorder known as "human BSE".
At the height of the cattle epidemic in 1992 there were 37,000 confirmed cases of BSE a year, which fell to 309 reported cases last year. Scientists hoped that the introduction of the reinforced feed ban in 1996 would eliminate the disease completely within 10 years or so. However, the new cases could extend the epidemic well into the next decade.
Christopher Higgins, chairman of the Government's Spongiform Encephalopathy Advisory Committee, said the occurrence of two clusters of BSE in young cattle suggested that contaminated feed was still being given to cattle. "Of course it is worrying and it's the aim of everyone to eliminate BSE but I guess at least we know why it's happening and no system is perfect," Professor Higgins said.
Experiments at the Government's Veterinary Laboratory Agency have shown that cattle can be infected by minute amounts of BSE-contaminated feed and some farmers may be unwittingly infecting their herds by using old containers that still contain traces of feed dating to before 1996, Professor Higgins said.
The risks to human health were minimal because of measures designed to protect the food chain from BSE-contaminated material, he said.
The Government nevertheless intends to continue with its plan later this year to relax the restrictions on allowing cattle over 30 months of age into the food chain - which are currently banned from human consumption.
Last December the Department for Environment, Food and Rural Affairs announced that cattle born after the reinforced feed ban of August 1996 will be allowed into the human food chain provided they test negative for BSE. A spokesman for Defra said that the new cases of BSE in cattle born after the ban will not affect the "managed transition" towards a system of testing for BSE which will replace the over-30-month rule banning the consumption of older cattle.
The Government also hopes to persuade Brussels to allow the export of cattle born after the 1996 feed ban as soon as they become eligible for sale in the UK.Reuse content