What is E. coli?

E. coli (escherichia coli) is a type of bacteria that lives in the gut and is usually harmless.

There are many different strains (types) of E. coli. Some types of E. coli bacteria can make you sick. These harmful types are a common cause of bacterial diarrhoea. Some types can cause serious illness.

What are the symptoms of E. coli?

The symptoms of E. coli infection usually affect your stomach and intestines. Common symptoms include:

• watery diarrhoea, which may contain blood
• stomach cramps or pain
• nausea and vomiting
• mild fever
• feeling tired or unwell

These symptoms usually start 1 to 10 days after exposure to the bacteria. Most people will recover within a week.

E. coli can also enter the urinary system. This may lead to a urinary tract infection or kidney infection. Symptoms may include:

• pain or a burning feeling when urinating (weeing)
• a feeling you need to wee more often than usual
• blood in your urine
• fever
• pain in your abdomen, back or side

What causes E. coli infection?

E. coli infections develop when harmful types of the E. coli bacteria enter your body. This can happen if you have contact with:

• contaminated food or water — for example, eating undercooked meat, unwashed fruits or vegetables or drinking untreated water
• unpasteurised dairy products — for example, eating or drinking raw milk or products made from it
• infected people — especially if you are exposed to their vomit or poo
• infected animals — handling animals that carry the bacteria, such as farm animals or pets

You can also become infected with E. coli due to:

• poor personal hygiene — if you don't wash your hands after using the toilet or handling raw meat, the bacteria may spread to food or surfaces
• spread within your own body — harmful E. coli from your gut can lead to issues in other areas, such as urinary tract infections

When should I see my doctor?

You should see your doctor if you:

• have watery diarrhoea more than 6 times a day
• you have diarrhoea that isn't improving or is getting worse
• have bloody diarrhoea
• you have a high fever
• you have severe abdominal pain
• have signs of a urinary tract infection

Also see your doctor if you show signs of dehydration, such as:

• feeling extremely tired
• feeling very thirsty or having a dry mouth or tongue
• muscle cramps or dizziness, especially when standing up
• confusion
• dark yellow urine, or not urinating for more than 5 hours

How is E. coli infection diagnosed?

To diagnose an E. coli infection, your doctor will usually refer you for laboratory tests. These tests may include:

• stool (poo) sample — a stool test can confirm the presence of E. coli bacteria in your digestive system
• urine test — a urine sample may be tested to identify the bacteria if you have a urinary tract infection
• blood test

How is E. coli infection treated?

Treatment for E. coli depends on what part of your body is infected and how serious your illness is.

• Drinking plenty of fluids helps prevent dehydration caused by diarrhoea.
• If you're hungry, eat light, easily digestible foods. Good options are potatoes, noodles, rice, oatmeal, crackers, bananas, soup and boiled vegetables.
• Oral rehydration solutions may help replace lost fluid, salts and minerals.

Antibiotics are not usually needed for mild E. coli infections. They often get better on their own. Antibiotics may be recommended if you have an infection that doesn't get better or you have severe symptoms. Young children, older adults and people with a weakened immune system may also need antibiotics.

Do not take antiemetic (anti-vomiting) or anti-diarrhoeal medicines unless your doctor has recommended them.

What are the complications of E. coli infection?

Sometimes, E. coli infection can lead to serious complications, especially with certain strains (types). These complications may include:

• severe, bloody diarrhoea that can lead to dehydration
• haemolytic uremic syndrome (HUS)
• sepsis
• organ damage, such as problems with the heart, brain or gut

E. coli infections in the urinary system may lead to repeated urinary infections or kidney damage.

Haemolytic uraemic syndrome

Some types of E. coli can cause a rare but serious illness called 'haemolytic uraemic syndrome'.

The E. coli bacteria that cause haemolytic uraemic syndrome make a toxin known as Shiga toxin. The toxin enters your bloodstream and damages your red blood cells. This can lead to anaemia and kidney failure.

Most people with E. coli infection don't have the strain that produces this toxin.

Can E. coli infections be prevented?

Here's how you can reduce your chance of E. coli infection.

• Avoid eating unclean or undercooked food.
• Always wash your hands after going to the toilet or changing a nappy.
• Prepare, cook and store your food safely. This will avoid transmitting E. coli bacteria from one food item to another.
• Wash raw fruits and vegetables in clean water to reduce any E. coli cross-contamination.

If you have been sick with E. coli, avoid preparing food for others in your household until you are symptom-free.

Stay away from work or keep your child home from childcare or school. Check with your workplace or school when it's safe to return.

Resources and support

• The Food Safety Information Council provides more information about E. coli.
• NSW Government Food Authority provides a video and information about food poisoning.
• NSW Health provides an E. coli infection and Haemolytic Uraemic Syndrome (HUS) fact sheet.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

Other languages

• Health Translations has translated information on food poisoning and how to prevent it.
• The Food Safety Information Council offers translated videos on food safety.
• The Victorian Government provides translated posters on food safety rules.

Looking for information for Aboriginal and/or Torres Strait Islander people?

• The Food Safety Information Council has information on Aboriginal and Torres Strait Islander peoples and food safety.