E. coli

Escherichia coli (E. coli)

What is Escherichia coli (E. coli)?

E. coli are bacteria that normally live harmlessly in the intestines of humans and animals. Unfortunately, some strains of E. coli can cause illness in people. Most people who do become ill will recover completely on their own, but some people may experience more serious illness.

How is E. coli spread?

To get sick from E.coli bacteria they have to be ingested. This can happen from contaminated water or food or through contact with people or animals who have the bacteria in their stool.

Sources of Infection


Drinking contaminated/untreated water

  • Drink treated or bottled water from a safe water supply. If you are a private well owner, test your well water seasonally
  • Avoid swallowing water when swimming or playing in lakes, ponds, streams, and swimming pools

Eating raw or undercooked meat

  • Use a probe thermometer to make sure meat has reached its proper cooking temperature (for example, ground beef is 71oC/160oF)
  • Store raw meat below and away from foods that are ready-to-eat.

Drinking raw or unpasteurized milk

  • Drink only pasteurized milk

Drinking raw or unpasteurized cider or juices

  • Drink only pasteurized cider or juices

Eating contaminated raw fruits or vegetables (example: lettuce, alfalfa sprouts)

  • Wash all fruits and vegetables separately under cold running water before eating; do not bathe them together in a sink full of water

Improper food handling and surface contamination

  • Clean and sanitize utensils, cooking equipment and food contact surfaces after they have come in contact with raw meat or vegetables (for example, lettuce)
  • Wash your hands with soap and warm water thoroughly and often, especially before eating or preparing food and after using the washroom

Touching infected people or animals

  • Wash your hands with soap and warm water thoroughly and often, especially before eating or preparing food and after using the washroom

What are the symptoms?

People who get infected with E. coli can have a wide range of symptoms. You may not get sick at all. If you do get sick, you may experience:

  • nausea
  • vomiting
  • headache
  • mild fever
  • severe stomach cramps
  • watery or bloody diarrhea

Symptoms appear within 1 to 10 days after exposure to E. coli bacteria. Most symptoms end within 5 to 10 days. While most people recover completely on their own, some people may have a more serious illness that:

  • requires hospital care
  • may lead to long-lasting health effects or death

Always see a doctor if you have:

  • diarrhea with blood
  • an illness that continues to worsen
  • an illness that is not getting better
  • any time you are worried

Avoid preparing food for other people if you think you are:

  • sick from E. coli infection
  • suffering from any other illness of the stomach or intestines

For more information about illness due to E. coli, how E. coli is spread and where it is found please visit Health Canada’s Causes of E. coli website.

Additional Resources about E. coli:

Contact Us