Escherichia coli Infection


Escherichia coli (E. coli) O157:H7 infection is a bacterial infection that is the leading cause of bloody diarrhea. This type of E. coli infection can require medical attention, so contact your doctor if you think you may have it.


E. coli infection is caused by certain types of the bacterium, E. coli. Most E. coli infections are caused by:

  • Eating undercooked beef, especially ground beef
  • Drinking contaminated water
  • Drinking unpasteurized milk
  • Working with cattle

Digestive Path through Intestines

Risk Factors

The following factors increase your chance of developing E. coli infection:

  • Age: children and older people
  • People with another illness
  • Working with cattle
  • Living in northern states




Your doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include:

  • Stool culture—to find out if you have E. coli O157:H7 in your intestines


Talk with your doctor about the best treatment plan for you. Treatment options include:

Fluid Replacement and Monitoring

Most people will recover from E. coli infection within 5-10 days without specific treatment. Avoid antidiarrheal medications, and drink plenty of water and fluids. Fluids through an intravenous (IV) line may be required in cases of severe dehydration.

Treatment for Hemolytic Uremic Syndrome (HUS)

HUS is a life-threatening condition that occurs in some people with E. coli O157:H7 infection. Symptoms may include pallor, tiredness, and irritability. Other signs include small, unexplained bruises, or bleeding from the nose or mouth caused by deficiencies in the body's clotting mechanism. HUS often requires blood transfusions and kidney dialysis.


To help prevent E. coli infection:

  • Cook all ground beef and hamburger thoroughly.
  • Avoid eating undercooked hamburger or other ground beef.
  • Keep raw meats separate from ready-to-eat foods.
  • Wash hands, counters, and utensils with hot soapy water after they are exposed to raw meat.
  • Drink only pasteurized milk, juice, and cider.
  • Wash fruits and vegetables under running water.
  • Drink municipal water that has been treated with a disinfectant (e.g., chlorine).
  • Wash hands after bowel movements and after changing soiled diapers.



Centers for Disease Control and Prevention

National Institute of Allergy and Infectious Diseases


E. coli infection. American Academy of Family Physicians website. Available at: Accessed February 28, 2007.

Escherichia coli O157:H7. Centers for Disease Control and Prevention website. Available at: Accessed February 28, 2007.