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What is Escherichia coli (E. coli)?

Escherichia coli, also called E. coli, are bacteria that are often found in the intestines of people and animals. There are different types of E. coli. Some types of E. coli are not harmful, but others like E. coli O157:H7, can make some people very sick. Usually illness is caused by eating contaminated food or water, having contact with someone who is sick with the bacteria, or animals that carry it.

What are the signs and symptoms?

Signs and symptoms can occur 2 to 10 days after E. coli get into the mouth.  They usually last less than five days.  Signs and symptoms may include:

  • Diarrhea (may be bloody)
  • Fever (generally not very high - usually less than 38.5˚C/101˚F)
  • Nausea and/or vomiting
  • Stomach cramps or pain

If you or a family member have any of the symptoms, it is important to wash your hands thoroughly after going to the washroom and before preparing food for other people in the family. If possible, have someone who is feeling well prepare the meals in the home.

How is it spread?​

Poor hand washing and improper food handling are often the way E.coli spreads. E. coli can be spread by:

Photo of bean sprouts

  • Eating a food source) such as undercooked ground beef, ham, turkey, roast beef, sandwich meats, unpasteurized apple cider and milk, or contaminated raw fruits and vegetables (including alfalfa and bean sprouts) and cheese. Person-to-person by fecal-oral route. For example, if someone with E.coli infection did not wash their hands properly and contaminated another person’s food with unwashed hands and improper food handling.
  • Putting anything in the mouth that has been in contact with infected stool (i.e., children’s toys). 
  • Direct contact with animals (petting zoos or farms)
  • Swallowing contaminated water (untreated drinking water and recreational water)
  • Contact with infected pets and animals (i.e., at farms and petting zoos).

Mainly poor hand washing and improper food handling are often the way E.coli spreads.

How long is it contagious?

E. coli is typically contagious for 1 week in adults and up to 3 weeks in children. 

What are the complications?

Young children and the elderly, especially, are at a higher risk for complications associated with E. coli, such as dehydration.  Some people with E. coli infection can develop a life-threatening complication called Hemolytic Uremic Syndrome, or HUS.  It usually develops 7 days after the start of diarrhea.  Signs and symptoms of HUS include:

  • Decrease in the amount of urine
  • Swelling of the face, hands, feet
  • Paleness of the skin
  • Irritability
  • Fatigue

It is important to watch for signs and symptoms of HUS, and see your health care provider immediately as it can be life-threatening.

Should I see a health care provider?

Photo of E. coli bacteria under a microscope

Anyone who shows signs and symptoms of E.coli should see their health care provider.

What is the treatment for E. coli?

Your health care provider will diagnose E. coli by taking a sample of your stool.

Treatment for E. coli usually includes treating the symptoms and preventing dehydration. This may require you to stay at the hospital.  Antibiotics and anti-diarrheal medications are not recommended as it may make the infection worse.

How can E. coli infections be prevented?

You can reduce your risk of getting an E. coli infection by following these tips:

Photo of raw ground beef

  • Thaw foods safely in the fridge, not at room temperature.
  • Cook meat thoroughly, until juices run clear and the meat is not pink.
  • Keep cold foods at 4°C (40°F) or lower. Keep hot foods at 60°C (140°F) or higher.
  • Drink only pasteurized milk, apple cider and orange juice.
  • Never let children sample milk produced directly from an animal.
  • Wash all fruits and vegetables with clean water before eating.
  • Wash hands often and thoroughly with warm water and soap. It's very important to wash hands before preparing food or eating, and after using the toilet, changing diapers, handling pets or livestock or their food. 
  • Clean and sanitize countertops, cutting boards and utensils after preparing raw meats and poultry. The sanitizing solution is made with 5 ml (1 tsp) of unscented bleach in 750 ml (3 cups) of water.
  • Use separate work surfaces and utensils for preparing raw and cooked foods.
  • Only drink water from a safe water supply. Do not drink from open streams or lakes.
  • Test private small drinking water systems (wells) for bacteria
  • Store raw meats on the bottom shelves of the fridge and use a container large enough to prevent any raw juices from dripping onto other foods. Keep raw foods away from other foods when shopping, storing, preparing and serving foods.
  • If you are sick with diarrhea, try to avoid preparing and handling food others will be eating.
  • Do not swim in public pools, or share baths and spas with others if you have diarrhea.
  • Do not go to work if you are a food handler, work in childcare, attend childcare/school, or healthcare. (The Health Unit will direct exclusions with the person and their health care provider).

Health Care Providers:

Verotoxin-producing E. coli infection indicator conditions including: Haemolytic Uraemic Syndrome (HUS) is reportable to the Health Unit immediately. Laboratories are required to fax lab confirmed case information to the Health Unit at 226-783-2132.

Exclude symptomatic food handlers, healthcare providers, and day care staff and attendees until 2 consecutive negative stool specimens (and at least 48 hours after the completion of antibiotics)

If you have any questions or concerns please call 519-258-2146 ext. 1420 during business hours.

For further information about human diagnostic testing, contact Public Health Ontario Laboratories Customer Service (Consulting with Health Care Providers on laboratory testing) or call toll free: 1-877-604-4567.