How to wash lettuce safely after parasites found on ready to eat vegetables

People have been warned to take extra precautions when eating salad leaves and other ready-to eat vegetables amid concerns over their safety. Both the parasite cryptosporidium and the bacteria E. coli have raised concerns over food poisoning after being found on foods.

Scientists found cryptosporidium on ready to eat vegetables in supermarkets in Kent while more than 200 people have been hit in an E. coli outbreak thought to be in lettuce which has seen thousands of sandwiches recalled from places including Aldi, Asda, Tesco, Morrisons, Sainsbury's and Boots.

According to the Food Standards Agency people should always wash fruit and vegetables with water before you eat them to make sure that they are clean. It says: "You should wash them under a running tap, or in a bowl of fresh water, making sure to rub their skin under the water.

"We advise that you start with the least soiled items first and give each of them a final rinse. Peeling vegetables can also remove more bacteria, so this is an additional step you can take before eating root vegetables raw."

Cryptosporidium is a highly contagious bug which causes sickness and diarrhoea. Researchers from the University of Kent checked 36 samples of ready-to-eat vegetables from a number of different, unnamed, supermarkets across Canterbury between May and July 2023.

Twelve of the samples did not meet the standards to be included however of the remaining 24, 58% tested positive for cryptosporidium. Four - almost one in five of the bags - produced similarities to cryptosporidium parvum - the leading cause of human cryptosporidiosis.

E. coli is a bacteria which is normally harmless and found in the intestines of humans and animals. However it can make some people seriously ill, especially the elderly, young children or those with weakened immune systems.

Latest figures for the current outbreak showed 256 confirmed patients had contracted the Shiga toxin-producing E. coli (STEC) O145 since late May. At least 86 people have been admitted to hospital as a result.

Investigations are ongoing into its source however sandwiches have been recalled after people fell ill with lettuce believed to be the source of the infection. The Food Standards Agency said the bacteria had not been found in many of those brands being recalled however the withdrawal from sale was as a precaution.

Now Richard Price, Owner of Brit Superstore, has explained how to properly wash lettuce to ensure it is free from bacteria such as E.coli and how to check groceries are safe to eat. Speaking after the latest E.coli outbreak he said: "It’s incredibly important to wash lettuce thoroughly to prevent ingestion of harmful bacteria from the soil that can contaminate fruit and vegetables, and lead to foodborne illnesses."

Richard's four steps to washing lettuce

1. Wash your hands with soap for 20 seconds before handling any produce

2. Fill your sink around ⅔ full with cold water and add 3 or 4 tablespoons of baking soda to the cold water

3. Submerge the lettuce in the water with baking soda for around 12-15 minutes. Push the head of lettuce down into the water to ensure it is fully submerged.

4. Remove the produce from the water and allow it to dry thoroughly before eating. To soak up any moisture, try layering the leaves between tea towels or kitchen roll.

He added: "Whilst you can’t see E.Coli on produce, the best way to prevent contamination is to practice safe food handling on a daily basis. Ensure meat is properly cooked, and thoroughly wash fruits and vegetables before eating.”