Huge surge in stomach bug linked to tainted SALAD could explain explosion of colon cancer in young people, disturbing new study suggests
Health officials have sounded the alarm over a worrying surge in a potentially deadly bacteria linked to colon cancer.
Rates of a rare strain of the diarrhoea-causing bug E.coli, rose almost 10-fold in just seven years, fresh figures show.
British researchers found more than 9,000 people in England were infected with a strain of the bacteria linked to cancer – called non-0157 shiga toxin-producing E.coli, or STEC – between 2016 and 2023.
In nine cases, the stomach bug proved fatal.
The pathogen is mostly found in ready-to-eat foods like chopped fruit and lettuce in sandwiches, as well as undercooked meat.
Last year, more than 280 people were struck down by STEC in an outbreak linked to ready meal sandwiches containing contaminated lettuce grown in the UK.
It comes as shock new research yesterday also suggested E.coli — including STEC strains — may be to blame for a disturbing rise in colon cancer cases in under 50s.
They found traces of colibactin, a cancer-linked toxin which is produced by certain strains such as non-0157 STEC, lurking in tumors from patients under 40.
Symptoms of Shiga toxin-producing E.coli include severe diarrhoea and vomiting, according to the UK Health Security Agency
Studies have even shown leafy greens are responsible for up to 58 per cent of E. Coli outbreaks. Experts believe lettuce’s texture can make it more prone to the bacteria, with it even getting stuck inside the vegetable
In the fresh data, collected by the UK Health Security Agency (UKHSA), scientists said cases of the E.coli strain had increased year on year from 297 in 2016 to 2,341 in 2023.
A total of 9,311 individuals have been affected overall over the seven year period.
Of these, 840 people required hospitalisation, with 173 developing hemolytic uremic syndrome (HUS) — a life-threatening condition that can lead to kidney failure.
Writing in the Journal of Medical Microbiology, the researchers said: ‘Over the last decade, notifications of cases infected with non-O157 STEC in England have increased.’
They added that an increase in widespread testing could be partly to blame for the rise in cases, but the data represents a ‘true increase in the clinical and public health burden’ of the infection.
It comes as concerning research yesterday suggested E.coli may be to blame for a disturbing rise in colon cancer cases in under 50s, a phenomenon that has baffled doctors around the globe.
US researchers analysed the DNA of 981 colon cancer tumours in patients aged either under 40 or over 70, across 11 countries.
They found traces of colibactin, a cancer-linked toxin produced by certain strains of E. Coli, lurking in tumors from patients under 40.
Limited research has also previously shown that the toxin colibactin is produced by some non-O157 STEC strains.
Writing in the journal Nature, the scientists suggested colibactin-linked cases could be 3.3 times more common in early-onset cancer than in those diagnosed after the age of 70.
Responding to the research, scientists acknowledged it was ‘strong’ and ‘good quality research’, but noted longer term studies tracking the effects of colibactin on children as they grow up were first necessary.
This would be needed to fully establish whether the toxin causes cancer or is just associated with it, they added.
Other research will also be necessary to work out what leads to the growth of E. coli strains that produce colibactin in the first place.
There are around 44,000 cases of bowel cancer every year in the UK and 142,000 in the US, making it the fourth most common cancer in both countries.
Cancer Research UK estimates that over half (54 per cent) of bowel cancer cases in the UK are preventable.
An investigation by food safety experts linked the 2024 outbreak of Shiga toxin-producing E.coli (STEC) — a rare strain of the diarrhoea-causing bug E.coli — to multiple types of ready meal sandwiches containing lettuce
Symptoms often include changes in bowel movements such as consistent and new diarrhoea or constipation, needing or feeling the need to poo more or less frequently and blood in the stool.
Stomach pain, a lump in the stomach, bloating, unexpected weight-loss and fatigue are among other signs.
Anyone experiencing these symptoms should contact their GP for advice.
STEC can be spread by touching infected animals or their faeces directly, as well as coming into direct contact with infected people’s waste, for example in the case of carers looking after older people.
It can also be spread through contaminated water, either via drinking tainted supplies it or accidently ingesting it while swimming.
Last year more than 60 sandwiches, wraps and salads sold in 11 major shops in the UK were slapped with ‘do not eat’ alerts over fears they could contain STEC.
The outbreak sickened 288 patients, caused nine cases of HUS and two deaths, the UKHSA said.
Experts believe lettuce’s texture can make it more prone to the bacteria and fact it’s not cooked, which would usually kill off bugs, increases the risk.
However, the infection is often difficult to spot because the same symptoms can be caused by a variety of bugs, including norovirus.
