The animal welfare group Compassion in World Farming - whose findings were privately dismissed as "alarmist" by the farming industry - said there could be "catastrophic consequences for human health" without urgent reform.
The CWF report, which draws together research from around the world, drew concern from consumer groups yesterday. It claims that one in three chilled, raw chickens contain salmonella, nearly half of fresh chickens contain diarrhoea-causing campylobacter and that a quarter of raw pork sausages and 22 per cent of raw beefburgers contain E. coli.
It also describes how food poisoning in England and Wales has increased six-fold over the past 15 years, costing the taxpayer and industry between pounds 1bn and pounds 3bn a year. Equally, huge amounts of antibiotics were routinely used on farms to control the "bug explosion", leading to the risk of mutated bacteria resistant to the drugs.
The report's author Dr Tim O'Brien said the main responsibility should not simply fall on consumers to ensure that food is properly prepared. "It's no good blaming the poor housewife or whoever cooks the food. The problem is at source on the farm."
He said: "The massive over-use of antibiotics on factory farms, to try to contain the inevitable explosion of bacteria and to push animals further beyond their natural growth rates, is a strategy doomed to failure.
"It may constitute an uncontrolled experiment in bacterial genetic engineering on an enormous scale, with potentially catastrophic consequences for human health."
The CWF's claims brought a swift denial from the chicken industry. Peter Bradnock, chief executive of the British Poultry Meat Federation said: "There is no link between the way in which poultry is reared and the rise in the level of food poisoning, and there is certainly no question of a `bug explosion' on chicken farms." Reports suggested the levels of salmonella in British chicken flocks has been reducing significantly over the last several years, he said.
Hugh Oliver-Bellasis, head of food policy for the National Farmers Union, denied that consumers were at risk, and said evidence showed that disease was no more prevalent in intensive-farmed flocks of chickens than in free- range hens.
A spokesman for Sainsbury's said they were constantly looking at the issue of food safety, but said evidence pointed away from claims that intensive farming led to more salmonella. A Tesco spokesman said they were committed to ensuring products came from animals reared to the "highest standards of welfare and husbandry".
However, Julie Sheppard, senior spokeswoman for the Consumers Association, said the report underlined that more steps needed to be taken at the farm rather than in the kitchen. "The consumer has been looked at as the last line of defence - at the moment it almost appears as if they are the only line of defence."
Food safety minister Jeff Rooker told the BBC Radio 4 programme Farming Today that intensive farming could cause problems and said the Government was pushing to make food safety the absolute priority of producers. "If intensive factory farming is not managed properly and corners are cut in terms of animal husbandry and animal health then we could end up with food that's not up to scratch, causing problems in the population," he said.
Mr Rooker added: "We are seeking to take measures to cut back on the use of drugs and chemicals in our food production.
"Sometimes it's going to make difficulties for people operating at the sharp edge for the fast and last buck in terms of farming production. But we do have to address this issue. People want cheap food - but they want safe food above all else."
After more than a year's research into eating habits, the Government is still unable to say how dangerous it was for Britons to eat burgers and other beef products when the epidemic of "mad cow disease" was at its height, writes Charles Arthur.
Though the Ministry of Agriculture, Fisheries and Food (MAFF) yesterday said it has commissioned a report about how much tissue with a high BSE risk went into food products, it did not admit that it has urgently been trying to establish exactly that fact for more than a year - at the request of its advisors on BSE and its human corollary, Creutzfeldt-Jakob Disease (CJD). The Independent first reported that MAFF had a private company carrying out an audit of the destination of potentially BSE-infected material in June 1996. Yesterday, Maff was still unable to say when the study will be completed.
Some data on eating habits has emerged. The British Medical Journal reports today that surveys show that in the 1980s young people, who have developed significantly more cases of the "new variant" of CJD - almost certainly caused by BSE - were eating far more kebabs, hamburgers and meat pies than older people, who have not figured in the v-CJD cases.
Until strict abattoir controls came into force in 1989, beef offal that might have been contaminated by BSE, such as brain and spinal, was allowed into the human food chain.Reuse content