What is E. coli?
E. coli (Escherichia coli) are a group of bacteria that are found in the gastrointestinal tract (the intestine) of nearly all healthy people. They are some of the beneficial bacteria in the gut that help to digest food.
However, some strains of E. coli are harmful and can cause illness. Most strains of E. coli make you mildly sick with watery diarrhea. Some cause a urinary tract infection. Less commonly, certain strains of Escherichia coli can cause severe illnesses such as pneumonia or meningitis.
Shiga-toxin producing E. coli (STEC) infections are the most common E.coli-related serious illnesses in the U.S., causing approximately 265,000 illnesses and about 100 deaths each year.
Types of E. coli Strains
Many strains of E. coli cause diarrheal infections (gastroenteritis) in the digestive tract, ranging from minor to serious. These E. coli strains are categorized according to how they attach to GI tract cells and the toxins they produce. E. coli strains that cause diarrheagenic illnesses include:
Shiga toxin-producing E. coli (STEC)
Enteropathogenic E. coli (EPEC)
Enterotoxigenic E. coli (ETEC)
Enteroaggregative E. coli (EAEC)
Diffusely adherent E. coli (DAEC)
Enteroinvasive E. coli (EIEC)
Other strains of E. coli are called uropathogenic (UPEC) and can cause urinary tract infections (UTIs). A strain of E. coli called K1 causes meningitis (a brain infection) in newborn babies. The subtype E. coli O157:H7 is most commonly associated with a severe illness.
Types of E. coli Infections
The two most common types of E. coli infections are diarrheal illnesses (gastroenteritis) and urinary tract infections. However, E. coli bacteria can also cause infections of the bloodstream, prostate gland, gallbladder, pelvic inflammatory disease (PID), wound infections, and rarely, pneumonia (lungs), and meningitis (brain).
Common Symptoms of E. coli Infection
Strains of E. coli that cause food poisoning or gastroenteritis are associated with symptoms such as abdominal pain, abdominal cramps, diarrhea, nausea, loss of appetite, and low fever.
WhenE. coli bacteria enter the urinary tract, they cause UTIs with symptoms such as a burning sensation or pain with urination, frequency, urgency, pelvic pain, and cloudy or foul-smelling urine.
You can have other symptoms depending on the part of the body infected with E. coli. For example, if E. coli enters the lungs, it can cause pneumonia. Shiga-toxin-producing E. coli (STEC) strains, also known as enterohemorrhagic E. coli (EHEC), can cause hemorrhagic colitis or bleeding in the intestines, causing bloody diarrhea. Some people with an STEC infection develop a serious illness called hemolytic uremic syndrome (HUS), in which blood clots form, which can lead to kidney damage and kidney failure.
How Soon Do E. Coli Symptoms Develop?
Symptoms of STEC infections typically start 3-5 days after eating or drinking food or beverages with E. coli contamination. Other strains can make you sick anywhere from a few hours to 10 days after exposure. For example, enterotoxigenic E. coli (ETEC) strains can cause traveler’s diarrhea within a few hours.
What is the Most Likely Way To Get E. coli?
How Does a Person Get E. coli Food Poisoning?
Diarrheal E. coli infections spread through fecal-oral transmission (from feces to the mouth). This can happen in the following ways:
Eating contaminated food such as raw fruits and vegetables and undercooked meat.
Drinking contaminated water, including drinking water from swimming pools and natural sources like rivers, streams, and lakes.
Drinking unpasteurized beverages and dairy products such as milk, cheese, ice cream, and juices.
Touching contaminated surfaces or feces (poop), for example, when wiping after a bowel movement, changing a baby’s diaper, touching animal poop, or touching contaminated surfaces. This can transfer bacteria from your hands to your mouth and GI tract.
Note: Babies sometimes contract an E. coli infection during birth.
Check out our blog to learn the difference between food poisoning and a stomach virus.
How Did I GetE. Coli In My Urinary Tract?
In addition to poor hygiene, E. coli infections in the urinary tract can develop if you wipe from back to front after using the bathroom. This can transfer E. coli bacteria from your anus (poop) to your urinary tract and cause a urinary tract infection.
Is E. coli Contagious?
Yes, E. coli is contagious and can spread with person-to-person contact. You do not get E. coli through coughing or sneezing. However, you can get it while caring for an infected person, especially if you come in contact with their stool. A person with E. coli can also spread the infection to others while handling or preparing food with unwashed hands.
Risk Factors for E. coli
People of all ages can develop E. coli infections if the harmful, disease-causing strains of E. coli enter the body. But some people are at a higher risk of these bacterial infections, particularly:
Infants
Young children
Older adults (above age 65)
People with medical conditions such as diabetes or ulcerative colitis
See AlsoWhat to Know About Pepto-BismolThose with weakened immune systems, for example, people with cancer or HIV (human immunodeficiency virus) or those taking certain immunosuppressant medications
How Do You Prevent E. Coli From Spreading?
Good Personal Hygiene
The best way to prevent E. coli infections is to wash your hands with soap and warm water. Hand washing is especially important:
After using the bathroom, changing diapers, or touching pets and farm animals
Before and after handling raw meat or poultry
Preventing Contaminated Food
The following food preparation practices can lower your risk of E. coli infections:
Wash all fruits and vegetables that are eaten raw with clean, running water. It is especially important to wash raw vegetables such as leafy greens.
Avoid rinsing risky foods like meat before cooking them. This can contaminate other foods, utensils, and surfaces.
Defrost frozen meat in a separate bag. Don’t thaw meat on the kitchen counter unwrapped.
Use a ceramic, plastic, or silicone cutting board for raw meat. These are easier to clean than wooden cutting boards.
Use different cutting boards for different foods to prevent cross-contamination. Raw meat can contaminate food that is prepped on the same cutting board. If you have only one cutting board, wash it thoroughly with dish detergent and hot water after using it for raw meat and before using it for other foods.
Do not eat undercooked hamburger meat, ground beef, or other meats. Make sure you cook all meat to a safe temperature.
Don’t place cooked meat on the same plate or surface where raw meats were stored.
Do not drink unpasteurized milk or raw milk, which may contain bacteria from the cow’s udder or milking equipment. Only drink pasteurized milk, ciders, and juices such as apple juice.
Refrigerate leftover food right away.
How AreE. Coli Infections Treated?
Treatment for E. coli depends on the type and severity. For example, you might recover from mild E. coli gastroenteritis in about a week without any specific treatment other than fluids and rest. Your doctor may prescribe antibiotics for an E. coli urinary tract infection. However, you may need to be hospitalized for a serious illness. Isolation may be necessary in case of E. coli outbreaks.
Do not take anti-diarrheal medications such as loperamide (Imodium) or bismuth subsalicylate (Kaopectate, Pepto-Bismol) if you are diagnosed with an STEC infection, especially the E. coli O157:H7 strain that makes Shiga toxin. These anti-diarrheal medicines can increase the risk of hemolytic uremic syndrome (HUS).
When to Seek Medical Help?
You should call your healthcare provider if you have symptoms of a urinary tract infection or diarrhea for more than 3 days. In addition, go to the nearest emergency room if you have the following signs and symptoms:
Bloody diarrhea
Chronic diarrhea that doesn’t go away or keeps coming back
Frequent vomiting
Inability to keep fluids down
High fever above 103 degrees Fahrenheit or 40 degrees Celsius
Reduced urine output
Weakness
Lethargy
Confusion, brain fog, or other mental status changes
