8 Things to Know About E. coli


Nancy LeBrun

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A very small microbe has made some very big news in the past months, as outbreaks of foodborne illness caused by the bacterium E. coli have sickened more than 50 people. If you’re uneasy about what you’ve been hearing and worried you might get sick, here’s some information to put any concerns into perspective:

1. There are good E. coli and bad E. coli.

There are hundreds of different types of E. coli bacteria. All healthy warm-blooded animals, including humans, have E. coli in their gut within a day or two after birth. Most of the bacteria are harmless or even beneficial–they help our digestive system break down food. 

So when you hear that people are getting sick from E. coli, it’s due to one of only six strains that produce “shiga” toxins, which are poisons that can get into your blood.  

2. E. coli contamination sources are limited.

Infections start when you swallow something that has miniscule amounts of feces in it that contain a disease-causing strain of E. coli. These microscopic quantities can go undetected during food processing and preparation. Undercooked beef is the most common source of contamination, but the bacteria can be present on people’s hands, in vegetable matter, and in water. In addition to places where food is processed or prepared, they can also be present in environments like farms, lakes and swimming pools.

3. Your risk of E. coli infection is very low.

About 265,000 people in the United States get an E. coli infection each year, which is less than 1% of the population—and serious cases are rare. However, infected people can still spread bacteria for several weeks or possibly months after they are feeling better, and young children tend to carry it longer than adults. 

4. E. coli infections usually last about a week or less.

An E. coli infection shows up anywhere from 1 to 10 days after exposure, usually causing severe stomach cramps, diarrhea (which may contain blood), and vomiting. You may have a mild fever or none at all. Most people get better within 5 to 7 days. However, if you have diarrhea that lasts for more than three days, or if you have a high fever, blood in the stool, or so much vomiting that you can’t keep down liquids, contact your healthcare provider.

5. Serious complications from E. coli are very rare.

One out of about every 50 people who are sick from E. coli becomes seriously ill, developing a condition called HUS (hemolytic uremic syndrome) that can lead to kidney failure. The most vulnerable are young children or the elderly. Signs of HUS, which tend to develop when diarrhea is improving, are urinating less frequently, feeling very tired, and losing the pink color in your cheeks and inside the lower eyelids. People with HUS are often hospitalized, though most recover within a few weeks. A few may have permanent damage. In 2014, there were three deaths from E. coli infection reported in the U.S.

6. E. coli infections usually go away by themselves.

E. coli infections are unpleasant, but rarely dangerous. That said, if you suspect you have one, it’s important to drink lots of liquids so you don’t become dehydrated. You shouldn’t take antibiotics, which have not been shown to be useful and may increase the chance of developing HUS. Over the counter anti-diarrheal medicines may also increase the risk of HUS and you should not use them. 

7. You can reduce your chance of getting sick from E. coli.

While your risk of E. coli infection is already extremely low, you can take steps to further reduce your possible exposure:

  • Avoid eating high-risk foods, especially undercooked ground beef, unpasteurized milk or juice, soft cheeses made from unpasteurized milk, unpasteurized apple cider, or alfalfa and raw bean sprouts. Contaminated food accounts for more than half the cases of E. coli illness.

  • When you cook ground beef, use a food thermometer to make sure it has reached an internal temperature of 160 degrees Fahrenheit. 

  • Wash your hands before preparing food, after diapering infants, and after contact with grazing animals like cows, sheep, goats, or their surroundings. 

  • Avoid water that has not been disinfected. 

  • Keep away from people who are ill with an E. coli infection. 

Though most cases of E. coli are not dangerous, contact your doctor if your symptoms do not go away within a few days.