What’s an E. coli Infection? (2024)

What are the symptoms of an E. coli infection?

Symptoms of E. coli gastroenteritis include:

• Diarrhea. This is often watery and sometimes bloody.
• Stomach pains and cramps.
• Loss of appetite.
• Low fever.

Watery diarrhea is usually the first symptom of an E. coli infection in your GI tract. You can also have different symptoms depending on where in your body you’re infected.

What are symptoms of E. coli in your urinary tract?

If E. coli infects parts of your urinary tract, you might have:

• Abdominal or pelvic pain.
• Pain or burning sensation when you pee.
• An urgent need to pee frequently.
• Cloudy, foul-smelling pee.

How soon do symptoms of an E. coli infection start?

You usually develop symptoms of an STEC infection within three to five days after drinking or eating foods contaminated with this E. coli bacteria. Other strains can make you sick within hours. Sometimes, symptoms start up to 10 days after exposure.

What causes E. coli infections?

Many strains of E. coli can cause diarrheagenic infections in your GI tract. Most cause similar symptoms, like watery diarrhea, but some are more serious than others. Scientists categorize them by how they attach to your cells and the types of toxins they release.

Types of diarrheagenic E. coli include:

• Shiga toxin-producing E. coli (STEC).
• Enterotoxigenic E. coli (ETEC).
• Enteropathogenic E. coli (EPEC).
• Enteroaggregative E. coli (EAEC).
• Enteroinvasive E. coli (EIEC).
• Diffusely adherent E. coli (DAEC).

Other notable types of E. coli include uropathogenic E. coli (UPEC), which can cause UTIs, and E. coli K1, which can cause meningitis in newborns.

What are Shiga toxin-producing E. coli (STEC)?

STEC is a strain of E. coli that releases a toxin (Shiga toxin) that damages your cells. These are the same toxins released by Shigella bacteria. STEC is known for causing severe outbreaks of E. coli (where many people get sick), often from contaminated food.

STEC is also called enterohemorrhagic E. coli (EHEC) because it can lead to bleeding in your intestines, causing bloody diarrhea (hemorrhagic colitis). About 5% to 10% of people with STEC develop hemolytic uremic syndrome (HUS), a condition that causes blood clots and damages your kidneys. The subtype E. coli O157:H7 is the most likely to cause severe illness.

What kind of E. coli causes traveler’s diarrhea?

Enterotoxigenic E. coli (ETEC) is a type of E. coli that causes infections known as traveler’s diarrhea. Symptoms start quickly after exposure — sometimes within just a few hours. ETEC is common in warm climates.

How do you get E. coli?

Most diarrheagenic E. coli strains spread through fecal-oral transmission. This happens when bacteria from poop that’s too small to see make their way into your mouth and digestive tract. Some forms, like STEC, can also transmit through undercooked meat and unpasteurized beverages.

Specifically, you can get E. coli from:

• Eating contaminated foods. This includes undercooked meat and raw fruits and veggies that aren’t washed well enough.
• Drinking unpasteurized beverages. This includes milk, cider or juice (and foods made from them, like cheese or ice cream).
• Drinking contaminated water (or getting it in your mouth). E. coli in poop from animals and people can contaminate natural water sources (like lakes, streams and rivers), swimming pools and drinking water that isn’t sanitized.
• Touching poop or contaminated surfaces. You can get poop on your hands from changing diapers, wiping after a bowel movement, touching petting zoo or farm animals, or sharing objects or surfaces with someone with an E. coli infection. You can swallow E. coli when it transfers from your hands to your mouth.
• Not wiping properly after going to the bathroom. This can move E. coli from your poop to your urinary tract, causing a UTI.

Babies sometimes get E. coli infections during birth.

Is E. coli contagious?

Yes, E. coli can be contagious (spread from person to person). While you don’t get it from sneezing or coughing, you can get it from caring for someone with an E. coli infection, especially if you come in contact with their poop. You can also get it from objects, surfaces or food someone with an E. coli infection has touched if they don’t wash their hands well enough.

Who’s at risk for E. coli?

Anyone who comes into contact with a disease-causing strain of E. coli can get infected. People who are at greatest risk include:

• Newborns and young children.
• People over the age of 65.
• People who have weakened immune systems (for example, those with HIV or cancer or who take immunosuppressive medications).
• People with diabetes.
• People with ulcerative colitis.

What are the complications of E. coli infections?

E. coli sometimes causes life-threatening complications, including:

• Hemolytic uremic syndrome (HUS).
• Sepsis, a serious reaction to an infection in your bloodstream.
• Malnutrition or delayed growth. Kids with chronic diarrhea may not be able to absorb the nutrients they need to grow.