Escherichia coli (E. coli) O157

Escherichia coli O157, sometimes called STEC (Shiga toxin-producing Escherichia coli), is a bacterial infection. It can cause severe stomach pain, bloody diarrhoea and kidney failure.

E. coli O157 is found in the gut and faeces of many animals, particularly cattle. It’s an uncommon cause of gastroenteritis but can be caught by:

  • eating contaminated food, such as raw leafy vegetables or undercooked meat – always wash all vegetables, including salad leaves, that will be eaten raw, unless they have been pre-prepared and are labelled ‘ready to eat’ (washing may reduce the risk of infection, but will not eliminate any risk of infection completely)
  • touching infected animals or accidentally coming into contact with their faeces
  • contact with people who have the illness, particularly if you do not wash your hands thoroughly after using the toilet or before handling food
  • drinking water from inadequately treated water supplies
  • swimming or playing in contaminated water, such as ponds or streams

When to get medical advice

Contact your GP practice and ask for an urgent appointment or phone 111 if:

  • you or your child has bloody diarrhoea

Speak to your GP practice if:

You or your child has diarrhoea and:

  • it’s particularly frequent or severe
  • it lasts for more than 7 days
  • a severe or continuous stomach ache
  • weight loss
  • have passed a large amount of very watery diarrhoea
  • have signs of dehydration – including drowsiness, peeing less than usual, and feeling lightheaded or dizzy

You should contact your GP if you have a child under 12 months and are concerned.

Symptoms of E. coli O157 infection

Symptoms include diarrhoea, stomach cramps and occasionally fever. About half of people with the infection will have bloody diarrhoea.

People usually notice symptoms 3 to 4 days after they have been infected. But symptoms can start any time between 1 and 14 days afterwards.

These symptoms can last up to 2 weeks.

Haemolytic uraemic syndrome (HUS)

A small number of people with E. coli O157 infection go on to develop a serious condition called haemolytic uraemic syndrome (HUS). Symptoms of HUS include:

  • peeing less
  • tiredness
  • swelling
  • bruising

This can sometimes lead to kidney failure and death, although this is rare. The risk of HUS is highest in children aged under 5 years.

Some people become infected but don’t develop symptoms.

Further information about gastroenteritis

Treatment and care at home

There is no specific treatment for E. coli O157 infection. People who are infected can usually be cared for at home and most will get better without medical treatment.

It’s important to drink plenty of fluids, as diarrhoea can lead to dehydration.

Antibiotics are not recommended, and may increase the risk of complications.

Anti-diarrhoea drugs such as loperamide (Imodium) are also not recommended as they may prolong your exposure to the toxin.

Find out more about caring for a child with gastroenteritis and caring for an adult with gastroenteritis.

How to prevent E. coli O157 from spreading at home

Strict hygiene measures are essential to stop others getting infected.


  • wash your hands thoroughly with soap in running water and dry them completely – use liquid soap and warm water if you can
  • everyone must wash their hands after contact with an infected person, particularly after handling their clothes or bedding
  • always wash your hands after going to the toilet or changing babies’ nappies, and before preparing or serving food or eating meals
  • if you’ve been infected, avoid cooking or preparing food until 48 hours after your symptoms have cleared up
  • wash soiled clothing and bed linen separately from other clothes in a washing machine at the highest temperature possible (for example 60°C)
  • wipe down the outside of the washing machine with hot water and detergent after any heavily soiled load
  • clean toilet seats, toilet flush handles, basin taps, surfaces and toilet door handles at least daily, preferably more often, using hot water and detergent
  • disinfection sprays and wipes or alcohol-based wipes may be used on toilet seats and other surfaces, but only after any visible soiling has been removed
  • thick household bleach is highly effective – dilute one part bleach to every 10 parts water for soiled surfaces and one part bleach to every 100 parts water for other hard surfaces
  • ideally, use heavy-duty domestic rubber gloves and disposable cloths for cleaning
  • dispose of cloths by placing them in a plastic bag, sealing the neck and placing in household waste
  • thoroughly wash rubber gloves in hot water and detergent after use, then rinse and allow to dry
  • deal with any spillage of faeces immediately – clean the soiled area with hot water and detergent using heavy-duty domestic rubber gloves then clean gloves and wash hands thoroughly


  • do not share towels or nappy changing mats
  • do not clean soiled items in the kitchen

Returning to work or school

Anyone who has had an E. coli O157 infection should stay away from work or school until they have been completely free of symptoms for 48 hours.

Most people are no longer infectious after about a week, although some people, particularly children, may carry E. coli O157 for several months after they have got better.

Some people need to take special care before returning to work or school.

If you work in health or social care, or your work involves handling food, you should ask your local authority environmental health officers about when it is safe to return to work. This advice applies to both people who have been infected and those who live in the same household as someone who has.

If you have a child under 5 years of age who has had E. coli, or lives with someone who has, you should talk to your GP about when it is safe for your child to return to school or nursery.

Children under 5 years of age who have had an E. coli O157 infection should not swim in public swimming pools, or share paddling pools with others, until they have had test results showing that they are no longer an infection risk to others.

Last updated:
07 June 2024