E. coli O157:H7

Escherichia coli (E. coli) O157:H7

Escherichia coli (abbreviated as E. coli) are a large and diverse group of bacteria. Although most strains of E. coli are harmless, others can make you sick. Some kinds of E. coli cause disease by making a toxin called Shiga toxin. The bacteria that make these toxins are called “Shiga toxin-producing” E. coli, or STEC for short. The most commonly identified STEC in North America is E. coli O157:H7.

 

What types of infections does E. coli cause?

E. coli can cause diarrhea, urinary tract infections, respiratory illness and pneumonia, as well as other illnesses. Carbapenem-resistant Enterobacteriaceae (CRE) are a family of germs that are difficult to treat because they have high levels of resistance to antibiotics. Escherichia coli (E. coli) is an example of Enterobacteriaceae, a normal part of the human gut bacteria, that can become carbapenem-resistant. In healthcare settings, CRE infections most commonly occur among patients who are receiving treatment for other conditions. Patients whose care requires devices like ventilators (breathing machines), urinary (bladder) catheters, or intravenous (vein) catheters, and patients who are taking long courses of certain antibiotics are most at risk for CRE infections.

Who is at risk for infection?

Anyone is at risk for infection from E. coli and should take the follow steps to prevent infection:

  • WASH YOUR HANDS thoroughly after using the bathroom or changing diapers and before preparing or eating food. WASH YOUR HANDS after contact with animals or their environments (at farms, petting zoos, fairs, even your own backyard).

  • COOK meats thoroughly. Ground beef and meat that has been needle-tenderized should be cooked to a temperature of at least 160°F/70˚C. It’s best to use a thermometer, as color is not a very reliable indicator of “doneness.”

  • AVOID raw milk, unpasteurized dairy products, and unpasteurized juices (like fresh apple cider).

  • AVOID swallowing water when swimming or playing in lakes, ponds, streams, swimming pools, and backyard “kiddie” pools.

  • PREVENT cross contamination in food preparation areas by thoroughly washing hands, counters, cutting boards, and utensils after they touch raw meat.

How is E. coli spread?

Infections start when you swallow E. coli—in other words, when you get tiny (usually invisible) amounts of human or animal feces in your mouth. Unfortunately, this happens more often than we would like to think about. Exposures that result in illness include consumption of contaminated food, consumption of unpasteurized (raw) milk, consumption of water that has not been disinfected, contact with cattle, or contact with the feces of infected people. Some foods are considered to carry such a high risk of infection with E. coli O157 or another germ that health officials recommend that people avoid them completely. These foods include unpasteurized (raw) milk, unpasteurized apple cider, and soft cheeses made from raw milk. Sometimes the contact is pretty obvious (working with cows at a dairy or changing diapers, for example), but sometimes it is not (like eating an undercooked hamburger or a contaminated piece of lettuce). People have gotten infected by swallowing lake water while swimming, touching the environment in petting zoos and other animal exhibits, and by eating food prepared by people who did not wash their hands well after using the toilet. Almost everyone has some risk of infection.

How are E. coli infections treated?

Non-specific supportive therapy, including hydration, is important. Antibiotics should not be used to treat this infection. There is no evidence that treatment with antibiotics is helpful, and taking antibiotics may increase the risk of hemolytic uremic syndrome (HUS). Antidiarrheal agents may also increase that risk.

 

Source: Centers for Disease Control and Prevention, http://www.cdc.gov/ecoli/general/index.html