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E. Coli Infection

What is an E. coli infection?

An E. coli infection is an infection by bacteria that can make you quite sick when you eat food contaminated with them.

How does it occur?

There are many harmless types of E. coli bacteria. However, some types, such as one called O157:H7, produce a strong poison, or toxin, which can make you very sick. The bacteria live in the intestines of cattle. Meat can become contaminated during the slaughter and meat-packing process. The bacteria may also get into a cow's milk. The bacteria can live in other animals as well.

Eating meat, especially ground beef, that has not been cooked long enough to kill E. coli can cause infection. Contaminated meat usually looks and smells normal.

Other possible sources of infection are:

  • alfalfa sprouts
  • leafy vegetables, such as lettuce and spinach
  • salami
  • milk, other dairy products, and juice that have not been pasteurized
  • contaminated water.

People who are infected have the bacteria in their bowel movements. The bacteria can spread from one person to another if an infected person does not carefully wash their hands after using the bathroom. Adults who care for toddlers who are not toilet trained are at high risk of getting the infection. These children's playmates may also get the infection.

You can become infected by swallowing unchlorinated or underchlorinated water in swimming pools contaminated by human waste. You can also get infected by swimming in sewage-contaminated water.

What are the symptoms?

Symptoms may include:

  • nausea
  • severe abdominal cramps
  • watery or bloody diarrhea
  • tiredness
  • vomiting
  • low-grade fever.

Symptoms usually begin 2 to 5 days after eating contaminated food. They may last for several days.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and examine you. A sample of your bowel movement will be tested in the lab.

How is it treated?

Usually you can get better without treatment. Antibiotics are usually not prescribed.

Ask your healthcare provider if medicines to stop the diarrhea are a good idea in your case.

You need to replace the fluids and body chemicals you lose when you have diarrhea. Your healthcare provider may advise you to drink plenty of clear fluids or to drink an oral rehydration solution.

How long will the effects last?

Most people get better in 5 to 10 days without medical treatment.

Rarely, a serious complication called hemolytic uremic syndrome (HUS) can develop. It can lead to kidney failure, especially in children. This life-threatening condition is usually treated in an intensive care unit of a hospital, sometimes with blood transfusions and temporary kidney dialysis.

How can I take care of myself?

  • For cramps or stomach pain, it may help to put a hot water bottle or electric heating pad on your stomach. Cover the hot water bottle with a towel or set the heating pad at low to prevent burns.
  • Do not take aspirin, ibuprofen, or other NSAIDS without checking first with your healthcare provider. It's OK to take acetaminophen (Tylenol).
  • You may want to let your bowel rest by drinking only clear liquids such as water, weak tea, bouillon, apple juice, or sports drinks or other oral rehydrating solutions. You may also drink soft drinks without caffeine (such as 7 UP) after letting them lose some of their carbonation (go flat). Make sure you drink often so you do not become dehydrated. Becoming dehydrated can be very dangerous, especially for children, older adults, and some people who have other medical problems. Suck on ice chips or Popsicles if you feel too nauseated to drink fluids.
  • When your symptoms have been gone for a few hours or after one day, add soft starchy foods to your diet. Foods that are easiest to digest are bananas, cooked cereal, rice, plain noodles, gelatin, eggs, toast or bread with jelly, and applesauce. Avoid milk products and caffeine for a few days. Return to your normal diet after 2 or 3 days, but for several days avoid fresh fruit (other than bananas), alcohol, greasy or fatty foods such as cheeseburgers or bacon, highly seasoned or spicy foods, and most fresh vegetables. Cooked carrots, potatoes, and squash are fine. If eating seems to worsen the diarrhea, let your bowel rest for a few hours by drinking just clear liquids.
  • If you keep having symptoms or your symptoms get worse, tell your healthcare provider.
  • Be cautious about taking nonprescription antidiarrheal medicines such as loperamide (Kaopectate or Imodium) or the prescription medicine Lomotil. These medicines can actually make the illness more severe, especially if the diarrhea is bloody. If you take one of these medicines, make sure you use only the dose recommended on the package. If you have chronic health problems, always check with your healthcare provider before you use any medicine for diarrhea.

How can I help prevent E. coli infection?

  • Cook all meat thoroughly. Because ground beef can brown while cooking before disease-causing bacteria are killed, use a meat thermometer to ensure thorough cooking. Ground beef should be cooked until a thermometer inserted into several parts of the patty reads at least 160°F (71°C).
  • Do not eat ground beef patties that are still pink in the middle. If you are served an undercooked hamburger in a restaurant, send it back for further cooking. Ask for a new bun and a clean plate, too.
  • Keep raw meat separate from ready-to-eat foods. Wash hands, counters, and utensils with hot soapy water after they touch raw meat. Never place cooked hamburgers or ground beef on an unwashed plate that held raw patties.
  • Drink only pasteurized milk, juice, or cider.
  • Wash fruits and vegetables thoroughly, especially those that will not be cooked. Children under 5 years of age, people with weakened immune systems, and older adults should avoid eating alfalfa sprouts. There is no way to decontaminate sprouts.
  • Drink tap water that has been treated with chlorine or other effective disinfectants.
  • Do not swallow lake or pool water while swimming.
  • Teach children to wash their hands carefully with soap after bowel movements to reduce the risk of spreading infection. Wash your hands after changing soiled diapers.
Developed by McKesson Corporation, including material from the Centers for Disease Control and National Institutes of Health.
Published by McKesson Corporation.
Last modified: 2007-03-29
Last reviewed: 2007-01-02
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright © 2007 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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