Soil linked to E.coli outbreak

Soil on vegetables has been linked to an E.coli outbreak earlier this year after analysis by the Health Protection Agency (HPA), which did not release the information earlier as it had no useful public health advice until it knew the source of the outbreak.

People have been warned to wash their fruit and vegetables thoroughly before eating.

Between December 2010 and July 2011, there were 250 recorded cases of people ill from infection of the E.coli bacteria – 74 of these were admitted to hospital. There are usually 81 cases per year across the UK, and the outbreak is now over.

Dr Andrew Wadge, chief scientist at the Food Standards Agency, said: “It’s sadly a myth that a little bit of dirt doesn’t do you any harm; soil can sometimes carry harmful bacteria and, although food producers have good systems in place to clean vegetables, the risk can never be entirely eliminated. Control of infection from E. coli O157 relies on an awareness of all potential sources of the bacteria and high standards of hygiene where it may be present.

“This outbreak is a timely reminder that it is essential to wash all fruits and vegetables, including salad, before you eat them, unless they are labelled ‘ready to eat’, to ensure that they are clean. It is also important to wash hands thoroughly as well as clean chopping boards, knives and other utensils after preparing vegetables to prevent cross contamination.”

The HPA undertook an analysis of 30 cases, compared with 62 control subjects. They found that those who fell ill were 40 times more likely to have been in a household where leeks were handled loose than a control subject, and 12 times more likely to have been in a household where potatoes were bought in sacks.

Dr Bob Adak, a gastrointestinal disease expert at the HPA and head of the multi-agency Outbreak Control Team, said: “Our study showed a statistically significant association with raw loose leeks and potatoes from sacks, but these vegetables may not be the only source of contamination.

“The vegetables could have carried traces of contaminated soil. It is possible people caught the infection from cross contamination in storage, inadequate washing of loose vegetables, insufficient hand washing after handling the vegetables or by failing to thoroughly clean kitchen equipment, utensils or surfaces after preparing the vegetables.”