Escherichia coli (E. coli) infections are a leading type of foodborne illness. According to estimates by the Centers for Disease Control and Prevention (CDC), approximately 73,000 cases of E. coli infection occur each year in the United States. These result in an estimated 2,100 hospitalizations and about 60 deaths each year.

Most cases of E. coli infection result from consuming food or water that has been contaminated by certain strains of the E. coli bacteria. Although many strains of E. coli live harmlessly in the intestines of cattle and humans, some strains cause illness. The most common cause of E. coli infection in the United States is eating undercooked, contaminated ground beef. In developing countries, contaminated water supplies are the most common source of infection.

Common symptoms of E. coli infection include bloody diarrhea and severe abdominal pain and cramping. A diagnosis of E. coli infection begins with a physical examination, which includes a medical history and a list of foods recently consumed and recent travel. Fecal tests can identify the presence of E. coli bacteria in stool. The very young, very old and people with immune system deficiencies have the greatest risk of developing E. coli infection.

Cases of E. coli infection that are mild can be treated at home by replacing lost fluids and electrolytes, which are necessary to maintain the body’s chemical balance. Antibiotics and antidiarrheals are not used to treat E. coli infections because they may worsen symptoms. More serious cases may be treated in a hospital where patients receive fluids intravenously (through a vein), or may be treated for complications that result from E. coli infection (e.g., anemia, kidney failure).

E. coli infection may be prevented in a variety of ways. For example, ground beef should be thoroughly cooked until it reaches a temperature of 160 degrees Fahrenheit (71 degrees Celsius). Unpasteurized milk and fruit juices should be avoided. Washing hands before and after food preparation and establishing separate cutting boards for raw meat can also help prevent E. coli infection. People with diarrhea should wash their hands frequently and should avoid swimming or any other situation where they may contaminate water used by other people.