E. coli blamed on weather as food poisoning doubles

Colonies of multi-resistant E. coli growing on a culture plate - Rodolfo Parulan Jr/Moment RF

The uncommonly wet weather of the past few months may have created the conditions that led to the current E. coli outbreak, according to experts.

The number of people falling ill from suspected food poisoning currently stands at 211 according to the UK Health Security Agency (UKHSA), virtually doubling in a week, although there may be more cases undetected so far.

Dozens of people who fell ill have been admitted to hospital. Food manufacturers have recalled dozens of sandwiches and other products all believed to be containing salad leaves from supermarket shelves, as a precaution.

Now experts have said they believed that the unusually wet recent weather may have created the conditions for E. coli to spread in lettuce or similar food plants.

Prof Eileen Wall, head of research at Scotland’s Rural College (SRUC) said: “The rainy but relatively warm weather we’ve been experiencing can create an ideal environment for the growth and spread of E. coli. Rain can cause contaminated water to splash onto the leaves of the lettuce, while warmth provides a favourable temperature for bacterial proliferation.”

She added that the bacteria can be present in the environment and transferred to the lettuce through irrigation water, particularly if the water is contaminated with faecal matter.

Dozens of sandwiches and other products all believed to contain salad leaves have been withdrawn from supermarket shelves - Maureen McLean/Alamy

Nicola Holden, a professor of food safety also at SRUC, a public land based research institution focused on agriculture and life sciences, also commented on the impact the current weather may be having on salad leaves.

She said: “The rainy weather means that for any field grown crops humidity will be higher within the leaf canopy. We know that STEC [E. coli] favours high humid conditions. However, it’s hard to directly say that rainy weather will result in better or more STEC bacteria associated with plant leaves.”

The Food Standards Agency (FSA) said on Saturday that it is “confident” an Apollo type lettuce has caused the outbreak, but that efforts to confirm the root cause are ongoing.

The FSA said it expects at least one more food manufacturer to recall products over the weekend, and that investigations are ongoing.

As of June 11, the number of cases associated with the E. coli (STEC) outbreak is 211, an increase of 98 since a previous update from the UK Health Security Agency on June 6. On Saturday the UK Health Security Agency confirmed that 67 people are currently hospitalised.

Product recall ‘precautionary’

While no bacteria has been found in supermarket products directly, Greencore Group and Samworth Brothers Manton Wood have recalled 45 products as a result of the outbreak as a “precautionary measure”. Greencore’s recalled products include sandwiches, wraps and salads sold at Sainsbury’s, Asda, Aldi, Morrisons, Co-op and Boots.

Jim Windship, director of The British Sandwich and Food to Go Association, said that “while investigations are still underway, we do know that warm and wet weather conditions are a perfect breeding ground for bacteria.”

Mr Windship added that consumers should also be aware that this lettuce is available to buy at supermarkets to make salads at home, as well as in food to go products.

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