UK Food Standards Agency demands dairy industry rid milk of suspect Crohn's bug
LONDON, England June 20, 2001 MILK contaminated with a form of TB could be triggering a crippling illness in humans, particularly children, it has been claimed.
A paper to be published by the Food Standards Agency this week demands action by the dairy industry to find new ways to treat milk and kill off the bug.
The move follows a study which discovered that the bug, known as MAP, can survive the heat-treatment process currently used by the industry.
The Dairy Council last night insisted that milk is still perfectly safe to drink and that the precautionary measures should not generate alarm.
At the same time, the Food Standards Agency said that milk continues to be a valuable and nutritious part of the diet.
The MAP bug has been linked to the development of Crohn's disease in humans, a chronic inflammation of the intestines.
Symptoms include stomach pain, vomiting, weight loss and diarrhoea, but the illness may also affect the joints, the eye, the liver and the lower back.
Medical experts are at odds over whether there is a link between the bug and the human condition.
But advisors to the FSA have decided the risk is sufficiently serious to require the dairy industry to introduce new safeguards.
The moves come against a background of warnings from independent experts that the scale of human illness involved far outweighs BSE.
Professor John Hermon-Taylor of St George's Hospital, London, estimates some 90,000 Britons are suffering from Crohn's disease caused by contaminated milk.
He claims that this total will grow at close to 5,000 cases every year unless action is taken to remove it from cattle and milk.
And he suggested an eradication policy may require the vaccination or culling of large numbers of infected cows.
'The risk that viable MAP is being transmitted to people via the milk supply is very, very high. The evidence is overwhelming,' he said.
'This bug can the destroy lives of the sufferers and their families. It causes real misery, but the great shame of this is that it could be prevented.'
The claims are disastrous news for British farmers struggling to recover from both BSE and more recently the foot and mouth crisis.
Consumers have always been told that the pasteurisation of milk - heating it to 72 degrees for 15 or 25 seconds - would be enough to kill off dangerous bugs.
But research ordered by the government's Advisory Committee on the Microbiological Safety of Food has now discovered that this is not the case.
It found that 2.1 per cent of pasteurised milk taken from eight different dairies across the UK contained MAP - Mycobacterium Avium Paratuberculosis.
With more than 10 billion pints of milk drunk in the UK every year - that equates to 575,342 pints containing MAP consumed every day.
Professor Hermon-Taylor believes these figures are likely to be an under-estimate because the bug is notoriously difficult to identify.
He calculates that some 30 per cent of the UK's cattle herds are likely to be carry MAP, which causes something similar to Crohn's disease - called Johne's disease - in cows.
'We know that livestock in Western Europe and North America are extensively infected with this MAP bug, and we know it gets into milk and humans are drinking it down,' he said.
'We also know that MAP is a specific cause of chronic inflammation of the intestines in animals, including at least four species of primates.
'You don't have to be a genius to think that it might be doing the same in humans.'
The professor said his own research, funded by the Medical Research Council, has found MAP in human sufferers, including a seven-year-old boy.
He stressed the presence of the bug was only likely to cause illness in those with a genetic or acquired vulnerability to the organism.
There is a suspicion that British and US pasteurisation techniques may allow MAP to survive in the milk reaching the public.
Supplies sold on the Continent tend to be the UHT - Ultra-Heat-Treated - which is more likely to destroy all the bugs.
The challenge facing the British industry is to come up with a process that works without destroying the fresh taste or imposing high costs.
The FSA's paper was written by Dr Eileen Rubery, of Cambridge University, who is a former Department of Health official and an expert on BSE.
Dr Rubery, said the jury was still out on a link between MAP and the human disease, but precautionary measures are necessary.
'Quite a lot of clinicians do not believe there is a link between Crohn's disease and MAP. They are strongly of the opinion there is no link.
'Nevertheless, there is some evidence there might be a link. I am sure that it is right that we should try to get rid of the organism on precautionary grounds.'
She said: 'There is a big study looking at ways of dealing with the bug in milk - not just pasteurisation, but other methods as well.
'You will probably end up with a combination of heating and some other treatment, but you have got to have a product that continues to taste like milk.'
The Dairy Council, which speaks for the industry, said it supported the need for precautionary measures, but warned against panic.
A new industry code of practise on pasteurisation has been drawn up and an expert committee will look at improving farm hygiene.
'The jury is out on the health issue. People do not need to rush away in huge alarm,' said a spokesman.
'The consequences of stopping drinking milk could be worse that continuing. People should be informed, but it would be a mistake to give up milk.'
The industry voluntarily increased pasteurisation time two years ago from 15 seconds to 25 seconds as a precautionary measure.
'We are now co-funding a major research project with the government looking at how to eliminate MAP from milk using pasteurisation,' she said.
This work is being carried out at Queens University, Belfast, but it will take two years to complete.
The National Association for Colitis and Crohn's Disease said more work is needed to investigate any link with MAP.
But its director, Richard Driscoll said: 'I don't think you can delay the work on pasteurisation or animal husbandry while you wait to find out whether there really is a link.
'Precautionary measures should be investigated, researched and undertaken wherever possible.'