E. coli

E. coli are bacteria that normally live in the intestines of humans and animals. Although most strains are harmless, some can cause illness by making a toxin called Shiga toxin. The bacteria that make these toxins are called Shiga toxin-producing E. coli, or STEC for short.

Healthy cows, goats, deer, and other animals can have STEC in their intestines. The bacteria can be present in their manure (droppings).

Anyone of any age can get a STEC infection, but young children and older adults are more likely to become seriously ill with complications.

Symptoms of E. coli Infection

Some infected people have mild diarrhea or no symptoms at all.

Contact your healthcare provider if you have these symptoms:

• Severe diarrhea
• Stomach cramps
• Blood in the stool

Usually, little or no fever is present.

A small number of people with STEC infection develop hemolytic uremic syndrome (HUS). This is a serious complication with damage to the kidneys and other organs that usually requires a long hospital stay. Fortunately, most people with HUS recover, but some suffer permanent kidney damage or die. Symptoms of HUS include urinating less frequently, feeling very tired, and losing the pink color in the cheeks and inside the lower eyelids. 

People usually get sick from STEC between 1 and 8 days (usually 2 to 3 days) after swallowing the bacteria. 

How People Get Infected

People usually get a STEC infection by eating contaminated food or drinks that have not been thoroughly cooked or pasteurized (heat-treated).

Cases and outbreaks of STEC infection have been traced to:

• Undercooked or raw beef (especially ground beef) contaminated with manure during slaughter or processing.
• Unpasteurized (raw) cow or goat milk contaminated with manure during milking.
• Unpasteurized juice or cider made with fruits that fell on the ground and became contaminated with animal manure.
• Raw produce, including sprouts and leafy greens (such as spinach), contaminated with animal manure in the field or during processing.
• Raw produce (or other ready-to-eat foods) contaminated by raw meat juices in the kitchen.
• Contaminated drinking or recreational water.

Infected people can spread STEC to others by not washing their hands thoroughly after pooping.

People can get STEC infection by having direct contact with livestock at fairs or petting zoos.

Swallowing water from STEC-contaminated lakes, streams, and swimming pools can lead to an infection.

How to Prevent E. coli Infection

• Don't eat raw beef or raw or under-cooked hamburger or other ground meat products. Cook all ground beef to 160°F.
• Keep ready-to-eat foods (like raw vegetables) away from raw meat.
• Drink only pasteurized (not raw) milk, milk products, and fruit juices, including apple cider.
• Carefully wash all produce, kitchen utensils, and counter tops after you handle meat.
• Wait to eat cookie dough and cake batter until fully baked.
• Wash your hands carefully with soap after using the toilet, changing a child's diaper, handling raw meat, or touching farm animals. Make sure your children wash their hands well after using the toilet.
• If you have diarrhea, don't swim in pools or lakes and don't prepare food for others. Keep children with diarrhea out of pools and lakes.
• Avoid swallowing water when swimming or playing in lakes, ponds, streams, and pools.

Treatment for E. coli Infection

Most people with a STEC infection get better on their own in 5 to 10 days. Studies suggest that antibiotics can make STEC infection worse. Treatment of STEC infection with antibiotics or anti-diarrhea medications is not recommended.

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