The UK Health Security Agency (UKHSA), together with public health agencies in Scotland, Northern Ireland and Wales, are investigating an increase in the number of Shiga toxin-producing E. coli (STEC) cases in the UK in recent weeks.

Whole genome sequencing of samples in the current investigation indicates that most cases are part of a single outbreak. Based on the wide geographic spread of cases, UKHSA believes it is most likely that this outbreak is linked to a nationally distributed food item or multiple food items.

The source of this outbreak is not yet confirmed but there is currently no evidence linking the outbreak to open farms, drinking water or swimming in contaminated seawater, lakes or rivers. The public health agencies are working with the Food Standards Agency (FSA) and Food Standards Scotland to investigate further.

Infections caused by STEC bacteria can cause severe bloody diarrhoea and, in some cases, more serious complications. It is often transmitted by eating contaminated food but can also be spread by close contact with an infected person, as well as direct contact with an infected animal or its environment.

As of 4th June, there have been 113 confirmed cases associated with this outbreak of STEC O145 in the UK, all reported since 25th May 2024:

  • 81 in England
  • 18 in Wales
  • 13 in Scotland
  • 1 in Northern Ireland (for this case, evidence suggests that they acquired their infection while visiting England)

Typically, UKHSA sees around 1,500 cases of STEC over a full year. Numbers of confirmed cases associated with this outbreak are expected to rise as further samples undergo whole genome sequencing.

Cases range in age from 2 years old to 79 years old, with the majority of cases in young adults. Of the 81 cases identified to date in England, 61 have provided information to UKHSA related to food, travel and potential exposures and of these we know that 61% have been hospitalised.