Updated: May 21, 2026
What is E. coli?
Escherichia coli (more commonly known as E. coli) are a large and diverse group of bacteria. Most strains of E. coli are harmless and can be naturally found in a healthy digestive system. They assist in food digestion, vitamin production, and help protect against harmful germs. However, certain strains of E. coli can cause illnesses such as diarrhea, urinary tract infections, pneumonia, sepsis, and more. Additionally, other kinds of E. coli are used as markers for water contamination. As a result, you may have heard or read about E. coli being found in drinking water. Discovery of these bacteria in drinking water may not necessarily be associated with illness but would indicate the water is contaminated.
What are Shiga toxin-producing E. coli?
Some kinds of E. coli (more specifically "Shiga toxin-producing" E. coli, or STEC for short) cause disease by making a toxin. These bacteria may also be called verocytotoxic E. coli (VTEC) or enterohemorrhagic E. coli (EHEC); these all refer generally to the same group of bacteria. While E. coli O157 is the most commonly identified type of STEC in the United States, there are numerous other types of Shiga toxin-producing E. coli (often referred to as "non-O157 STEC") that can also cause illness in people. The average number of annual STEC cases in South Carolina is 81 cases.
Are There Important Differences Between E. coli O157 and Other STEC?
Most of what we know about STEC comes from outbreak investigations and studies of E. coli O157 infections. The “non-O157 STEC” are not nearly as well understood, partly because outbreaks due to them are rarely identified. In general, the “non-O157 STEC” serogroup is less likely to cause severe illness than E. coli O157, though they can still lead to serious illness in some cases.
What are the symptoms?
Symptoms of E. coli infection may include watery or bloody diarrhea, fever, abdominal cramps, nausea, and vomiting. The symptoms experienced depends on the kind of E. coli causing infection. Illness may be mild or severe, but mild illness typically resolves in 5 to 10 days.
Who is at a greater risk of infection?
Groups of people at increased risk for E. coli infection include: Children younger than 5 years of age, adults 65 years and older, and people with weakened immune systems.
What is hemolytic uremic syndrome (HUS) and is it associated with STEC infections?
Hemolytic uremic syndrome (HUS) is a severe complication of Shiga toxin-producing E. coli (STEC) infection. It can result in kidney failure, long-term health issues, and even death. Symptoms include: reduced (or lack of) urination, loss of pinkness in the cheeks and inside the lower eyelids, unexplained bruising or small red spots on the skin, blood in the urine, extreme fatigue or irritability, and decreased alertness. People with HUS should be hospitalized because their kidneys could fail, and other serious complications may develop.
How is E. coli treated?
Most people usually recover without antibiotics or other specific treatment in 5-10 days. There is no evidence that antibiotics improve the course of disease, and it is thought that treatment with some antibiotics may cause kidney complications. Antidiarrheal agents, such as loperamide (Imodium®), are usually avoided; however, if you think you may be infected, see your provider and discuss your options.
How do people catch this disease?
Most illnesses have been associated with eating undercooked, contaminated ground beef. This is likely because contaminated meat may look and smell normal. Other possible sources of infection are consumption of unwashed vegetables, and unpasteurized milk or juice. Additionally, people should refrain from swimming in or drinking potentially contaminated water. Lastly, person-to-person contact in families and childcare centers is also an important mode of transmission.
Because there are so many possible sources, it is difficult to identify how most individuals were infected.
What can be done to stop the spread of this disease?
- People can help prevent E. coli O157 infection by thoroughly cooking ground beef, washing their hands, avoiding unpasteurized milk/juice, and washing fruits and vegetables.
- Because the organism lives in the intestines of healthy cattle, preventive measures on cattle farms and during meat processing are being investigated.
- When camping, hiking, or traveling, make sure to use safe water for drinking, cooking, brushing your teeth, and other activities. Do not swallow water while swimming or playing in lakes, ponds, streams, swimming pools, or backyard "kiddie" pools.