E. Coli Gastroenteritis: Transmission, Symptoms, and Potential Complications
Key takeaways:
Escherichia coli is a group of bacteria that often appears in food, the environment, and the gut of animals and humans. Most strains of E. coli don’t cause any serious health problems.
Some types of E. coli can make you sick and cause food poisoning. Most people have vomiting and diarrhea for about a week.
Some people with an E. coli infection can develop serious complications that are potentially life-threatening. There are ways to know if you have a severe case that needs medical attention.
If you’ve ever eaten an undercooked burger and then experienced nausea and vomiting soon after, you’ve likely had food poisoning (gastroenteritis). And Escherichia coli (E. coli) may have caused it.
Many Americans never seek medical attention for these symptoms and recover on their own at home. But understanding how the bacteria works can help you and those around you stay healthy. It’s also important to understand the potential complications of E. coli infections, so you know which signs to look for if you have a more serious infection.
What type of E. coli strains can cause food poisoning?
E.coli is a large family of bacteria that includes many different types. Several (not all) of them cause diarrhea. There are some strains of E.coli that cause pneumonia, urinary and bladder infections, blood infections, and other abdominal infections.
Five types of E. coli are associated with diarrhea:
Enterotoxigenic E. coli (ETEC) causes travelers’ diarrhea. This is common in people who travel from developed to developing countries. It causes a lot of watery diarrhea.
Enteropathogenic E. coli (EPEC) is similar, and it’s more common among young children in developing areas. It also causes watery diarrhea.
Enteroaggregative E. coli (EAEC) is yet another type that causes travelers’ diarrhea, like the two above.
Enterohemorrhagic E. coli (EHEC) differs from the other types because it produces the Shiga toxin (verotoxin). It’s also referred to as Shiga toxin-producing E. coli (STEC) or verotoxin-producing E.coli (VTEC). E. coli O157:H7 is a strain of EHEC that can cause bloody diarrhea and severe cramps.
Enteroinvasive E. coli (EIEC) is less common than the others. It causes bloody diarrhea and fever.
Don’t let all of these types and abbreviations confuse you. Most types of E. coli cause watery diarrhea and not much else. Only O157:H7 can lead to more severe complications. We provide more details on this below.
How do you get food poisoning from E. coli?
E. coli lives in many different places both inside and outside your body — and in animals. This means it can be spread from animals to humans or from person to person in different ways. You can develop food poisoning from E. coli through:
Contaminated foods: There’s a higher chance of contamination with E. coli if you eat raw, leafy vegetables, undercooked meat, or raw milk.
Contaminated water: Livestock may spread fecal matter into a nearby water source, which can then contaminate drinking water. Humans can also get infected if swimmers accidentally swallow pool water contaminated with feces.
Contaminated surfaces: People can get sick when they prepare foods on contaminated surfaces or use contaminated utensils. This can happen if someone uses the same cutting board and knife for raw meat and vegetables without thoroughly washing them between preparations.
But infection doesn’t always start with animals or food contamination. Humans can spread the bacteria directly to other humans.
Is E. coli contagious?
Yes, E. coli can spread from person to person. Beyond the ways you can get food poisoning from E. coli listed above, people can accidently spread it to others. For example, this can happen if someone uses the bathroom and then prepares a meal. Or they change a baby’s diaper and forget to wash their hands before eating.
People with an E. coli infection may not always experience symptoms. These people are called “silent carriers” because they carry the bacteria and can spread it to others without knowing.
What are the symptoms of E. coli food poisoning?
If a person develops food poisoning from E. coli, they may experience a range of symptoms. Commonly, people with food poisoning report:
Stomach cramps
Nausea
Abdominal pain
Vomiting
Diarrhea (ranging from mild and watery to severe and bloody)
Less frequent urination
Fever (temperature above 100.4°F)
Most often, people will develop symptoms within hours to a day of exposure to contaminated food or water. But, in some cases, they can take up to 1 week.
The symptoms usually go away on their own after 5 to 10 days. Though the symptoms may get better 24 to 48 hours after starting treatment.
How do you diagnose an E. coli infection?
Many people who have food poisoning from E. coli never get a formal diagnosis because the illness passes before they see a healthcare provider. Since many different bacteria can cause food poisoning, it’s impossible to know just from your symptoms and physical exam which bacteria is to blame. Usually this isn’t a problem because the treatment and recovery are the same.
But, sometimes, figuring out which bacteria is causing food poisoning does matter. The specific bacteria matters in these two cases:
It’s not clear if someone has food poisoning or a different condition.
Someone is very sick and needs more treatment.
In these cases, your provider can test your stool. This helps guide treatment by figuring out whether you have food poisoning from E. coli or a different bacteria.
How do you treat an E. coli infection?
Most often, people who have food poisoning from E. coli can recover at home. If you have watery diarrhea, treatment includes:
Fluids: It’s important to drink plenty of fluids to stay hydrated and replenish electrolytes, like sodium and potassium. The best things to drink when you’re sick are clear liquids like broth, watered-down juice, and oral rehydration fluids (Pedialyte, Oralyte).
Rest: Frequent nausea, vomiting, and episodes of diarrhea can be exhausting. Taking it easy can help conserve energy so your body can recover from food poisoning.
Antimotility agents: These medications help slow down the stool in the gut and may decrease the number of times you have a bowel movement. Examples include bismuth salicylate (Pepto-Bismol) and loperamide (Imodium A-D).
If you have more severe symptoms, treatment may also include:
IV (intravenous) fluids: If dehydration is severe or you can’t drink fluids by mouth, a healthcare provider may use IV fluids (fluid directly into the vein).
Antibiotics: Your provider may recommend antibiotics in certain cases. Examples include ciprofloxacin, levofloxacin, azithromycin, or rifampin. But most people do not need these to recover.
Treatment may look a little different if you have bloody diarrhea. In addition to fluids and rest, you may also need:
A blood transfusion: Some people with food poisoning will lose large amounts of blood in their stool. So infections with E. coli or other bacteria can lead to a decreased blood count (anemia). If these counts get low enough, your provider may recommend a blood transfusion.
Antibiotics: Antibiotics (ciprofloxacin, levofloxacin, azithromycin, or rifampin) may be used if a person has bloody diarrhea. But they are not recommended for anyone with EHEC because they can increase the chances of severe complications.
Anyone with bloody diarrhea should avoid antidiarrheal agents because they may cause you to feel sick for longer.
How dangerous is E. coli?
Certain types of E. coli are more dangerous than others. Most often, food poisoning caused by E. coli goes away on its own without any problems.
But, in certain cases, it can cause more harm. The complications that can arise from certain types of E. coli gastroenteritis include:
Severe dehydration: If left untreated, severe dehydration can be life-threatening. It can lead to decreased kidney function or severe electrolyte imbalances.
Anemia: Severe anemia can affect oxygen levels in vital organs. This can be particularly dangerous for people with other conditions that already limit blood flow, like heart disease.
Bacteremia: This is a serious infection that can happen if the bacteria travels from the gut to the bloodstream.
Sepsis: Sepsis is a life-threatening condition that can happen if someone’s immune system has an extreme response to an infection.
Hemolytic uremic syndrome and kidney failure: E. coli that produce shiga toxin are known to cause a complication called “hemolytic uremic syndrome.” In rare cases, it can cause life-threatening kidney failure.
When to see a healthcare provider
If you think you have food poisoning, you should never hesitate to reach out to your provider for guidance. But be sure to call them right away — or go to an ER — if you experience any of these symptoms:
Severe stomach pain
Significant decrease in urination
Urine that is very dark in color
Vomiting that prevents you from keeping anything down, even small sips of water
Bloody vomit
Stool that appears dark or tarry
A heart rate that feels fast or rapid
Dizziness or lightheadedness
Extreme fatigue or confusion
People with weakened immune systems, children under the age of 5, and adults older than 65 are at the greatest risk of developing more severe food poisoning from E. coli. They should go to the emergency room right away if they suspect they have it.
Can you prevent E. coli?
E. coli usually doesn’t lead to significant health problems. And the good news is that you can take steps to prevent it. To protect yourself and your loved ones from developing food poisoning, remember these tips:
Wash your hands. This is especially important after using the bathroom, before preparing and eating food, and after touching raw food.
Keep your cooking area clean. Use soap and hot water to clean utensils, cutting boards, counter tops, and any other surfaces where you prepare food.
Separate raw and cooked foods. Separate raw meats, fish, poultry, and eggs from other foods until they’re cooked.
Cook food thoroughly. Cook food to the right internal temperature to make sure you kill all harmful bacteria. Use a food thermometer to measure the temperature.
Don’t wait to store leftovers. Put your leftovers into the refrigerator within 2 hours of cooking. And if food is exposed to a hot temperature (above 90°F) after it is made, move it to the refrigerator within 1 hour. This could happen if it is left in a hot car or on a sunny windowsill.
Rinse your fruits and vegetables. Any foods that aren’t cooked before eating should be rinsed under tap water to remove bacteria.
Think before you drink. Avoid drinking unpasteurized milk or juice and water from streams or wells.
The bottom line
Although unpleasant, food poisoning from E. coli often isn’t serious. Most people can recover on their own with some rest and hydration. But certain types of E. coli will cause more serious symptoms — like bloody diarrhea, severe dehydration, or infection that starts to affect other organs. In these cases, it’s important to seek medical treatment right away. Close monitoring and more intense treatment in a hospital setting can help avoid complications.
Why trust our experts?
References
Ameer, M. A., et al. (2022). Escherichia coli (E coli 0157 H7). StatPearls.
Centers for Disease Control and Prevention. (2022). E. coli (Escherichia coli).
Centers for Disease Control and Prevention. (2022). Fast facts about food poisoning.
Centers for Disease Control and Prevention. (2022). Four steps to food safety: Clean, separate, cook, chill.
MedlinePlus. (2016). E. coli infections.
Mueller, M., et al. (2022). Escherichia coli. StatPearls.
National Kidney Foundation. (n.d.). Hemolytic uremic syndrome (HUS).
Paediatrics and Child Health. (2001). How to avoid food poisoning.
Panos, G. Z., et al. (2006). Systematic review: Are antibiotics detrimental or beneficial for the treatment of patients with Escherichia coli O157:H7 infection?. Alimentary Pharmacology and Therapeutics.
U.S. Food and Drug Administration. (2019). Escherichia coli (E. coli).
World Health Organization. (2018). E. coli.
