Shiga toxin-producing E. coli (STEC)

Escherichia coli (E. coli) are bacteria that live in the environment, in food, and in the intestines of animals and people. Most types are harmless, and they're a necessary part of a healthy digestive tract. Some, though, can make you unwell.

E. coli can be split into 2 groups:

• those that can produce Shiga toxin, known as Shiga toxin-producing E. coli (STEC), which includes E. coli O157
• those that can't produce Shiga toxin

STEC are known to cause more severe illness than E. coli that don't produce Shiga toxin. STEC infection can cause severe stomach pain, bloody diarrhoea and kidney failure.

Symptoms of Shiga toxin-producing E. coli (STEC) infection usually start 2 to 4 days after you become infected. In some people they can begin at any point between 1 and 14 days afterwards.

The symptoms are:

• diarrhoea
• stomach pain
• vomiting
• fever
• bloody diarrhoea

Most people get better within 5 to 7 days, but sometimes the symptoms last up to 2 weeks.

Some people carry the infection and never develop symptoms. This is known as asymptomatic carriage.

A small number of people with STEC infection, mainly children, go on to develop a serious, life-threatening condition called haemolytic uraemic syndrome (HUS). The signs to look for are:

• peeing less
• pee that is pink or brown in colour
• tiredness
• swelling
• bruising

HUS can sometimes lead to kidney failure and death, though this is rare. Children under 5 years of age have the highest risk of developing it.

• you or your child has bloody diarrhoea

If you can't reach your doctor, call the 16263 health line.

You or your child has diarrhoea and:

• it's particularly frequent or severe
• it lasts for more than 7 days
• there is vomiting that lasts for more than 2 days
• you keep being sick and can't keep fluids down
• there is a severe or continuous stomach ache
• you have lost weight
• you have passed a large amount of very watery diarrhoea
• you have signs of dehydration, like dark, smelly pee or peeing less than usual

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

There is no specific treatment for Shiga toxin-producing E. coli (STEC) infection. Most people who are infected can manage their symptoms at home.

In most cases, people get better without any medical treatment. But STEC infection can be serious, and some people need to be admitted to hospital.

Drink plenty of fluids, because diarrhoea can leave you dehydrated.

Antibiotics are not recommended in most cases, and they may raise the risk of complications. Anti-diarrhoeal medicines such as loperamide (Imodium) are not recommended in most cases either. They may prolong your exposure to the toxin.

You can also read more about caring for a child with gastroenteritis and caring for an adult with gastroenteritis.

STEC infection is an uncommon cause of gastroenteritis. You can catch it in a few different ways.

Food that is contaminated can cause Shiga toxin-producing E. coli (STEC) infection. It can happen in a few ways:

• eating food that hasn't been cooked or reheated thoroughly
• eating raw vegetables and salad leaves
• handling contaminated food, like raw meat or vegetables

Wash all vegetables, salad leaves included, every time. Washing may lower the risk of infection, but it won't remove the risk completely.

Unpasteurised dairy products can carry harmful bacteria, and Shiga toxin-producing E. coli (STEC) is one of them. Some people are more vulnerable if they eat or drink these products, and their risk is higher. They include:

• people aged 65 years or over
• pregnant women
• infants and small children
• people with a condition that weakens your immune system, like HIV

You can get a Shiga toxin-producing E. coli (STEC) infection from contaminated water. It can happen in a few ways:

• drinking contaminated water from water supplies that haven't been treated properly
• drinking contaminated water from streams, rivers and lakes
• swimming or playing in contaminated water, like ponds or streams

Close contact with animals, or with the places where they live, can lead to Shiga toxin-producing E. coli (STEC) infection. Cattle, sheep and goats are the main concern. The bacteria can be found in animal faeces (poo) and may also be found in animal saliva. You can pick up the infection through close contact with:

• animals
• animal pens
• surfaces contaminated with animal poo, even if it's not visible

On farm visits, STEC can also spread through:

• contact with contaminated footwear or clothing
• eating or drinking while you're in close contact with animals (so wash your hands after touching animals or their surroundings, and before you handle any food)

You can catch Shiga toxin-producing E. coli (STEC) infection through contact with someone who already has it. This can happen when hands aren't washed properly:

• after using the toilet
• after changing nappies
• before handling food

Strict hygiene at home is needed to stop others from catching STEC.

• wash your hands thoroughly with soap in running water and dry them completely (use liquid soap and warm water if you can)
• wash your hands after contact with an infected person, their clothes or bedding
• after any cleaning activities, including handling laundry and waste disposal, wash your hands again
• wash your hands after going to the toilet or changing babies' nappies, and before preparing, serving or eating food
• make sure you wash your hands after contact with animals or their environment
• wash any clothing or bedding that has poo or vomit on it separately on a hot wash
• wipe down the outside of the washing machine with hot water and detergent after any heavily soiled load
• clean toilet seats, flush handles, taps, surfaces and door handles with disinfectant at least daily, more often if possible
• disinfect any surfaces or objects that could be contaminated, and it's best to use a bleach-based household cleaner
• deal with any spillage of poo immediately, cleaning the soiled area with hot water and detergent (ideally using gloves), then wash your hands thoroughly
• dispose of cloths by placing them in a plastic bag, sealing the neck and placing it in household waste
• clean animal poo from footwear or buggy wheels after visits to animal attractions, and wash your hands after doing so

• do not prepare food for others until 48 hours after your symptoms have stopped, if possible
• do not share towels or nappy changing mats
• do not bring soiled items into the kitchen to clean them, if possible

If you wear gloves while cleaning, disposable ones should be used once only and thrown away properly afterwards. Reusable gloves need to be cleaned thoroughly after each use and left to dry. Even if you've worn gloves, always wash your hands thoroughly once you have taken them off or cleaned them.

If you've had a Shiga toxin-producing E. coli (STEC) infection, stay away from work or school until you've been completely free of symptoms for 48 hours.

Most people are no longer infectious after about a week. But some people, children in particular, may carry STEC for several months after they've got better. So they can still be infectious and pass it on to others.

Some people need to take special care before they go back to work or school. Their job or their age puts them at higher risk of passing the infection on to others.

Ask your doctor when it's safe to return to work if:

• you work in health or social care
• you work in a childcare setting
• your work involves handling food

You'll be asked to give stool (poo) samples to show you no longer have the Shiga toxin-producing E. coli (STEC) infection. This advice applies to people who've been:

• infected with STEC
• told they've been in close contact with someone who is infected with STEC

Speak to a doctor or the 16263 health line about when it's safe for your child to return to school or nursery. Your child will need to give stool (poo) samples to show they're no longer infected with STEC if they're aged 5 years or younger and have:

• had STEC
• been told they're a close contact of someone with STEC, or there are concerns about the hand hygiene of an older child

They'll also need test results showing they're no longer infected with STEC before they can:

• swim in public swimming pools
• share paddling pools with others
• go to soft play areas and similar premises

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