Dangerous gut infections caused by E. coli bacteria soared by more than a quarter in England last year—with one major outbreak traced to contaminated salad leaves, health officials have warned.
According to new figures from the UK Health Security Agency (UKHSA), 2,544 culture-confirmed cases of Shiga toxin-producing Escherichia coli (STEC) were reported last year—a 26 per cent increase compared to 2,018 cases in 2023.
These included 564 cases of STEC serotype O157—the strain historically linked to the most severe illness.
There were 1,980 cases of other STEC serotypes (non-O157), which have become increasingly common and, while once considered less dangerous, are now known to cause serious complications and the majority of STEC-related deaths.
Some studies have suggested that chronic exposure to certain toxin-producing strains of E. coli, including STEC, may play a role in bowel cancer development—though more research is needed to confirm a direct link.
Typically, STEC bacteria causes gastroenteritis, with symptoms ranging from mild to bloody diarrhoea, stomach cramps, vomiting and dehydration.
In severe cases, they can lead to haemolytic uraemic syndrome (HUS)—a life-threatening complication that affects the kidneys.
Food can become contaminated with STEC through contact with animal faeces during farming, slaughter, or processing. It can also occur if produce like salad leaves is irrigated or washed with contaminated water.
Dangerous gut infections caused by E. coli bacteria soared by more than a quarter in England last year – with one major outbreak traced to contaminated salad leaves, health officials say
UK Health Security Agency (UKHSA) said 2,544 confirmed cases of Shiga toxin-producing Escherichia coli (STEC) were reported last year—a 26 per cent increase year on year
The increase in 2024 was partly driven by a major outbreak linked to contaminated salad, which resulted in 293 cases across the UK, including 196 in England.
Of those affected, 126 required hospital care, 11 developed HUS and two died.
UKHSA Dr Gauri Godbole food poisoning expert said: ‘It is important for people to take steps to prevent infection.
‘Rarely STEC can progress to cause kidney failure and life-threatening illness, particularly in young children and elderly.
‘Please consult your GP or healthcare professional if you have blood in your stools or severe dehydration and continue to hydrate yourself.’
The highest number of cases in 2024 was seen among children aged one to four years, with 84 cases of STEC O157 and 273 cases of non-O157.
UKHSA said this may be due to a combination of factors, including naturally lower immunity, poor hygiene practices, and increased exposure to risk factors such as contact with farm animals, especially at petting farms.
Travel-related cases rose by 60.5 per cent—from 114 in 2023 to 183 in 2024.
Some studies have suggested that chronic exposure to certain toxin-producing strains of E. coli, including STEC, may play a role in bowel cancer development
UKHSA and its partner agencies investigated five outbreaks of STEC during 2024, accounting for 467 cases—348 of them in England
UKHSA said this may reflect changes in international travel patterns or improved ascertainment of travel history during investigations, although the exact cause remains unclear.
In 2024, there were seven deaths recorded in total—two linked to STEC O157 and five to non-O157 strains.
The UKHSA investigated five outbreaks of STEC during 2024, accounting for 467 cases—348 of them in England.
All were caused by STEC non-O157. The sources for three of the outbreaks were identified as contaminated beef, fresh fruit and salad leaves.
Non-O157 cases have increased nearly threefold since 2019.
UKHSA said this rise is partly due to increased use of diagnostic methods such as polymerase chain reaction (PCR) testing, which has improved detection.
While STEC O157 cases tend to peak in the summer months, non-O157 cases typically peak in autumn—prompting a warning that infections can occur throughout the year.
Natasha Smith, Director of Food Policy at the Food Standards Agency (FSA), said: ‘Public safety is our highest priority. The FSA works closely with UKHSA and other partners to monitor and assess the latest foodborne disease data.
Typically, STEC bacteria causes gastroenteritis, with symptoms ranging from mild to bloody diarrhoea, stomach cramps, vomiting and dehydration
‘We are working together to understand the reasons behind the rise in STEC cases, as well as trends in other pathogens, to help us take the necessary action to protect public health.
‘We’ve launched a new food safety campaign to help people stay safe—find out more on food.gov.uk.
‘We’re also working with local authorities and industry to support businesses meet their legal responsibility to make sure food is safe. Consumers can further protect themselves by checking Food Hygiene Ratings on our website before eating out.
‘When preparing food at home, people can reduce their risk of food poisoning by following good hygiene practices and by following advice on the 4Cs of food hygiene: chilling, cleaning, cooking, and avoiding cross-contamination.’
The 4Cs include keeping food chilled below 5°C to slow bacterial growth, cleaning equipment and surfaces thoroughly, cooking food to the correct time and temperature, and avoiding cross-contamination by keeping raw and cooked foods separate.
The FSA also urges consumers to observe ‘use by’ dates and not to rely on the look or smell of food, as harmful bacteria like STEC cannot be detected through taste or odour.
