Enterohemorrhagic Escherichia coli Infection

ExitCare ImageEnterohemorrhagic Escherichia coli (EHEC) infection is a common cause of bloody diarrhea. Strains of the bacterium Escherichia coli (E. coli), such as the strain type O157:H7, cause this disease. The bacterium produces a toxin that severely damages the cells lining the inside wall of the intestines. This damage causes bloody diarrhea. Diarrhea typically starts 2 to 4 days after ingesting the EHEC bacteria and usually lasts for 1 to 8 days. Two serious complications may also follow EHEC infection in up to 10% of infected people. Hemolytic uremic syndrome (HUS) is a complication that is most likely to occur in young children. Thrombotic thrombocytopenic purpura (TTP) is a rarer complication that follows EHEC infection in adults. Both of these complications can be life-threatening.


The most common source for EHEC bacteria is the intestinal tract of healthy cattle. Beef gets contaminated if the intestinal contents come in contact with the meat during slaughtering or processing. People then get the infection from eating undercooked beef, especially ground beef. People can also get infected from drinking unpasteurized milk or eating foods that were contaminated by feces from cattle and deer in the field, such as bean sprouts, green onions, lettuce, and apples used to make apple juice. People can also get this infection from contact with animals at petting zoos and county fairs or from swimming in lakes contaminated with the bacteria. The infection can also be passed from person to person.


  • Abdominal cramps and tenderness.

  • Watery diarrhea, followed by bloody diarrhea.

  • Very mild fever. In some cases, there may be no fever at all.

People who develop HUS may have other symptoms including:

  • Weakness.

  • Excessive tiredness.

  • Lightheadedness.

  • Seizures.

  • Nausea.

  • Vomiting.

People who develop TTP may have:

  • Seizures.

  • Stroke.

  • Coma.

  • Problems with movement.


Your caregiver may suspect you have EHEC infection based on your history and your symptoms. A stool sample will be taken and tested for toxin-producing E. coli. A colonoscopy may be done if your caregiver thinks other diseases may be causing your symptoms. This exam involves placing a thin, flexible tube into your rectum. The tube has a light source and a tiny video camera in it. Your caregiver uses the tube to look at the entire colon.


The most important part of treatment is drinking enough fluids. You may be given fluids through an intravenous (IV) tube if you cannot drink enough fluids on your own. Antibiotics are not given because they do not shorten the length of the illness and they increase the risk of developing HUS. People who develop HUS or TTP usually need care in the hospital. Kidney dialysis treatment may also be needed.


  • Ask your caregiver about specific rehydration instructions.

  • Drink enough fluids to keep your urine clear or pale yellow.

  • Drink small amounts of clear liquids frequently. Clear liquids include water, broth, weak tea, and lemon-lime sodas.

  • Avoid:

  • Foods or drinks high in sugar.

  • Carbonated drinks.

  • Juice.

  • Extremely hot or cold fluids.

  • Drinks with caffeine.

  • Fatty, greasy foods.

  • Alcohol.

  • Tobacco.

  • Overeating.

  • Gelatin desserts.

  • You may consume probiotics. Probiotics are active cultures of beneficial bacteria. They may lessen the amount and number of diarrheal stools in adults. Probiotics can be found in yogurt with active cultures and in supplements.

  • Wash your hands well to avoid spreading the bacteria to others.

  • Only take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver. Do not give aspirin to children.

  • If the patient is a child, weigh your child 2 to 3 times per day and record his or her weight. Ask your caregiver how much weight loss should concern you.


  • You are unable to keep fluids down.

  • Your vomiting or diarrhea becomes worse or persistent.

  • You have abdominal pain and it increases or stays in one area (localizes).

  • You develop a fever.

  • Your diarrhea contains more blood over time.

  • You feel very weak, dizzy, thirsty, or you faint.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.