Certain types of bacteria found in the pre-cut salad bags can be almost impossible to kill, Professor Hugh Pennington said, unless the leaves are irradiated – a process the public would oppose.
His claim follows a Health Protection Agency investigation into an outbreak of salad-linked Cryptosporidium infections that affected around 300 people in England and Scotland in May.
In the analysis of the exposure to different salad vegetables a significant statistical association was found between infection and the consumption of pre-cut spinach.
When specific retailers were included in the analysis, the strongest association with infection was found to be with consumption of ready to eat pre-cut mixed salad leaves from a major supermarket chain.
Professor Pennington said the case also followed on from several in the USA where they are “very worried” about “washed and ready-to-eat” bagged salad.
Last year produce giant Dole issued a recall on its American Blend bagged salad in 10 states in those two regions, after the Tennessee Department of Health found listeria bacteria in one sample.
Demand for salad has boomed because of healthily eating campaigns. But salad is considered one of the products most likely to cause food-related illness – largely because greens are grown directly in the soil, and some pathogens can only be killed by heat or strong detergents, not just water.
“I would advise people to thoroughly wash salad even when it says it has been washed and is ready to eat.”
Bagged salad on sale in supermarkets is often sourced from the same suppliers for most leaf types, often with common production lines packing product for several retailers at the same time.
“Vegetables are fine and safe if they are cooked in the traditional way of boiling them to death. The only danger comes when you eat them raw.
“Sometimes the spouts are contaminated to start with and they can get contaminated when spouting in the steaming process.
“At the end of the day the responsibility falls on the people who produce food. But much of our vegetables are now grown in countries who do not necessarily have the same hygiene standards.
“At the end of the day there has to be trust who is in supplying you with your food. The consumer has no way of knowing how the food has been produced. The consumer is not in a position to know all that has gone on.”
Professor Pennington headed the investigation into the E.coli outbreak in Wishaw which claimed the lives of 20 elderly people in 1996.
Culled from telegraph.co.uk
