Shiga toxin-producing E.coli (STEC)

Shiga toxin-producing E.coli (STEC) are a group of bacteria which cause illness in humans. Symptoms can include diarrhoea, abdominal pain and fever.  In Northern Ireland, the most common serotypes are O157 and O26. In a small number of people STEC can cause a serious illness called Haemolytic Uraemic Syndrome (HUS). This condition affects the blood and blood vessels and can result in kidney failure. The risk of HUS is highest in children aged five years and under.

Sometimes STEC is referred to a Verocytotoxin-producing E Coli (VTEC). These are different names for the same group of bacteria.

STEC is very infectious and can be easily passed to others. People can become infected by:

  • eating infected/contaminated food that has not been cooked all the way through, particularly minced meat products such as burgers and sausages, or salad items that have not been washed properly;
  • handling/preparation of food contaminated with soil for example, potatoes and leeks where the soil has not been washed away;
  • drinking infected/contaminated water such as from streams, rivers and lakes etc. which may contain animal poo;
  • close contact with animals, particularly cattle, sheep and goats. Animal saliva may be infected because of the way animals clean themselves;
  • direct contact with animal poo on the animal itself, in their pen or on the floor;
  • contact with an infected person, particularly if you don’t wash your hands thoroughly after using the toilet or before handling food.

There are some simple steps that can be taken to prevent others from getting ill. These include:

  • Stay away from work/school/nursery until 48 hours after you’ve stopped vomiting or having diarrhoea and comply with any additional exclusions recommended by the Environmental Health and/or PHA Health Protection team.
  • Wash hands thoroughly with liquid soap and running water after using the toilet (or helping others including changing nappies), handling raw meat, before meals and after contact with animals. If you have false nails, pay particular attention to cleaning these thoroughly;
  • Clean hard surfaces including toilet bowls, flush handles, taps and hand basins regularly with hot soapy water followed by a disinfectant/sanitiser;
  • Wash dirty clothes, bedding and towels on the hottest wash cycle possible and do not share towels or face flannels with someone who is infected;
  • Clean animal faeces from footwear/buggy wheels after visits to animal attractions and wash your hands after doing so;
  • Raw and cooked food should be kept completely separate, raw meat should be cooked through and vegetables and fruit should be washed thoroughly before eating.

Everyone should follow these simple steps to prevent the spread of STEC - not just people with symptoms.

For further information see: Shiga toxin-producing Escherichia coli - An information leaflet for cases

Returning to school, work or childcare settings

Any cause of vomiting or diarrhoea

Anyone with vomiting and/or diarrhoea should not go to school, work or childcare settings until at least 48 hours after the last episode of vomiting or diarrhoea.

Specific advice for STEC

Some people have extra requirements before returning to work, school or childcare settings. If someone with STEC works with vulnerable people in a health and social care role or handles food at work, they will have to stay away (be excluded) from work and submit poo samples to show that they no longer have the infection.

These requirements also apply to children aged five years or under (up to sixth birthday). Some children aged five years and under have also been shown to continue to pass STEC in their poo for longer than adults, sometimes for many weeks or even months.

For these reasons, children aged five years and under may need to stay away (be excluded) from childcare settings until their poo samples are clear of the infection. If there are other children aged five years and under in the household, they may also be excluded, whether they have symptoms or not, until poo samples show that they have not picked up the infection.

PHA Health Protection and/or Environmental Health Officers will advise if exclusion is required. They will provide you with information on this clearance process and aim to support your child back to normal activities as quickly as possible.

Further guidance on infection control in schools and other childcare settings is available from Guidance on infection control in schools and other childcare settings | HSC Public Health Agency (

Investigation Questionnaire: Surveillance of Escherichia Coli O157 infection Version 3.pdf