New BSE inquiry raises fears over milk safety 

Jonathan Leake, Science Editor 

Is it a threat? Britain consumes nearly 14 billion litres of cows' milk a year

A NATIONWIDE investigation into the risk that milk could transmit BSE between cows and humans is being launched by the Food Standards Agency (FSA). The move follows private warnings from scientists that the original experiment used to declare milk safe was flawed. 
This weekend Professor Malcolm Ferguson-Smith, the Cambridge University geneticist who sat on the two-year BSE inquiry, criticised the agriculture ministry for not doing the necessary work. "It is astonishing that this research has not been done," he said. 
he new investigation coincides with fresh figures on the spread of variant CJD (vCJD), the human equivalent of BSE, showing that the number dead or dying from the disease has risen to 90. It has also emerged that the number of people aged over 50 dying from the disease has risen to six. It had been thought that it was mainly a disease of the young. 
The main research used to declare milk safe was published in 1995. It was based on giving milk from cows with BSE to mice, orally and by direct injection into the brain. None of the 275 mice in the research developed any sign of the disease. 
Although scientists say there is no evidence at present to suggest that milk is unsafe, Ferguson-Smith believes the experiment was flawed because of the species barrier that prevents BSE passing from cows to mice. This, he said, made it highly unlikely that any of the mice would have fallen ill. 
He said the work should also have been done in calves, adding: "This would have been a thousand times more sensitive." 
Tastes all right: 11-year-old Victoria Robinson, from Halifax, enjoys a glass 
We warned that milk should be assumed to have the potential to carry infection. Pointing out that BSE spreads via the lymphoreticular system, a loose network of organs involved in the immune system, he said: "Milk contains mammary cells, cell organelles and cells from the lymphoreticular system. It therefore has the potential to transmit prion diseases." 
Britain consumes about 14 billion litres of milk a year, of which half is as milk or cream and the rest cheese, yoghurt and other dairy products. Tests suggest none of the processing methods could kill prions, the deformed proteins thought to cause BSE and CJD. The majority of the 1m or so animals thought to have entered the human food chain while infected with BSE were dairy cows, whose milk would have been consumed for years before they died. 
Most of the scientists and politicians involved in the BSE crisis have taken comfort from the fact that there is little positive evidence that prion diseases can be transmitted by mothers' milk. 
In Papua New Guinea, where the Fore tribe was almost wiped out by kuru, a prion disease spread by cannibalism, studies have shown that suckling children did not get the disease from their mothers. Only consumption of flesh, especially brains and other nervous tissue, seemed to pass it on. 
There is, however, some evidence that other prion diseases can spread through mothers' milk. In Japan, researchers tested tissues taken from a pregnant woman who died of sporadic CJD, a rare form that killed 38 people in Britain last year. They found that her colostrum - secreted in the first few days after a child is born - could pass the disease to mice. 
There is also a mystery over the mechanism by which calves seem to get BSE from their mothers. Some evidence suggests that they are infected in the womb and other work suggests that milk could be a cause. 
An FSA spokesman said the Central Veterinary Laboratories, a government agency, had been commissioned to start the research in the next few weeks. It would involve trying to infect calves known to be free of BSE with milk from diseased animals. The research will take at least three years - the time it takes cattle to incubate BSE. 
The spokesman said there was no evidence yet regarding milk, but added: "We have identified this project as a priority." 

BSE and transmission to humans via milk

The consumption of milk and milk products has largely been unaffected as there is long standing scientific advice that BSE cannot be transmitted to humans through milk.  Despite this, the Food Standards Agency (FSA) has commissioned a three year research project to be carried out to identify whether BSE can be transmitted to humans through milk.  The FSA has described this simply as a continuation of current research into the entire subject of BSE, and has stated that "they believed milk is safe for humans to consume" (although milk from suspected BSE infected cows is kept out of the food chain as a precaution).  The research is to be carried out by the Central Veterinary Laboratory. 
The new research will involve the feeding of milk from infected cows to healthy calves.  Previous research involved feeding milk from infected cows to rodents. 
The new German Agricultural Minister Renate Kuenast has also raised the possibility of a link between BSE and milk, saying that "nobody can rule it out", although she accepted that there is no evidence to suggest a proven link.

Eddie
Dr Edward Oliver, UK

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EDM - European Dairy Magazine´s

UK: the Food Standards Agency (FSA) is set to carry out research to determine if mad cow disease can be transmitted through milk. The investigation follows concern that previous research, which appeared to show that BSE could not be passed on through milk, was flawed. "This is not a new investigation but part of ongoing research into BSE," an FSA spokeswoman said. "We will be carrying out further work." The Government-run Central Veterinary Laboratory will conduct the investigation, which is expected to take three years to complete. Scientists will study whether prions can be transmitted through milk from an infected cow. Milk had already been declared safe after scientists fed or injected milk from infected cows into mice and none of the rodents developed the disease. But Professor Malcolm Ferguson-Smith, a geneticist at Cambridge University who took part in a two-year inquiry into BSE, has said that more research is needed because the mouse experiments were flawed. He said a species barrier would have prevented BSE from passing though to mice and suggested that tests on healthy calves would be 1000 times more effective. The new research will study whether healthy calves fed on milk from diseased cows can be infected with BSE. "The research we have shows that milk is safe for people to consume. Having said that the milk from any animals that are BSE suspect is not allowed to go into the food chain as a precautionary measure," the FSA representative said. (Jan 16)