Escherichia coli (E. coli)

E. coli are bacteria that usually live in the intestines. While most types of this bacteria are harmless, some types of E. coli — called Shiga toxin-producing E. coli (STEC) — can cause severe diarrhea and kidney damage. The most common harmful strain of Shiga toxin-producing E. coli is called E. coli O157:H7.

You can become infected with Shiga toxin-producing E. coli by drinking water or eating food that is contaminated with the organism. You can also become sick through contact with infected people or animals.

Any person can get Shiga toxin-producing E. coli infection, but children are the most likely to develop serious complications, such as hemolytic uremic syndrome (HUS). People who experience such complications may require blood transfusions or kidney dialysis. Most people with these complications recover completely, but the complications can be fatal.


Shiga toxin-producing E. coli infections are often linked to consuming contaminated beef products that are not thoroughly cooked. Shiga toxin-producing E. coli outbreaks have also been traced to unpasteurized milk, raw leafy vegetables or unpasteurized apple cider made from apples contaminated by cow manure. Infections can also be spread person-to-person. Other sources of exposure include contact with animals such as cows.

One way to avoid infection is to practice good hand hygiene. Wash hands with soap and warm water before and after touching food, after using the bathroom or diaper contact and when taking care of someone with a Shiga toxin-producing E. coli infection.

To keep your food safe from bacteria:

  • Use separate shopping bags for raw meats while food shopping.
  • Refrigerate foods quickly.
  • Use separate cutting boards for raw meats and other foods.
  • Wash counters and cooking tools with hot soapy water before and after preparing raw meats.
  • Make sure meat and poultry are thoroughly cooked on the inside to the recommended temperatures, especially when using a microwave. Make sure your cooked meat is brown throughout (not pink), and the juices run clear.
  • Avoid eating raw eggs, and be sure to thoroughly cook foods that contain raw eggs.
  • Avoid eating raw or undercooked meats.
  • Drink only pasteurized milk and milk products.
  • Avoid unpasteurized apple cider.


If you have been infected with Shiga toxin-producing E. coli, you may start to experience the following symptoms in one to nine days:

  • Diarrhea
  • Abdominal pain
  • Blood in the stool
  • Low fever

Once you are infected, you may have the bacteria in your stool for anywhere between several days and few weeks.

Diagnosis and Treatment

Doctors can test for Shiga toxin-producing E. coli through stool tests. Most infected people recover without antibiotics or other specific treatment in five to 10 days. Antibiotics and anti-diarrheal medicines are not recommended.

Returning to Work or School

Shiga toxin-producing E. coli bacteria live in the stool, so people should stay home from work, school or day care if they have diarrhea. Once their stools are solid, people can return to work or school.

Food handlers, health care workers, daycare employees and children in day care who are younger than 5 years, must get approval from the Health Department before they can return to their routine activities. This may involve follow-up stool testing to be sure that they are no longer infectious.

More Information

For data on E.coli in New York City visit EpiQuery .