E coli infection symptoms

E. coli Infection

Escherichia coli (E. coli) is a bacteria that is found in the intestines of both humans and animals. In most cases, this bacteria is harmless, and helps in the digestion of food. However, certain strains of E. coli can cause infection and symptoms, including diarrhea. Some of the infections can be dangerous.

What is an E. coli infection?

The strains of E. coli that cause symptoms of diarrhea are known as Shiga toxin-producing E. coli (STEC) and toxigenic E. coli. (The STEC that is most well-known and most often referred to is E. coli O157:H7.) Other strains can cause diseases such as pneumonia and urinary tract infections. The incubation period (the period between exposure to the E. coli bacteria and when symptoms appear) ranges from one to 10 days.

Who can get an E. coli infection?

An E. coli infection can affect anyone who comes in contact with the bacteria. People who are at greatest risk are the very young, the elderly, and people who have weakened immune systems.

What are the symptoms of an E. coli infection?

People who get infections with the STEC strain of E. coli can have the following symptoms:

  • Abdominal pains and cramps
  • Diarrhea and bloody stools
  • Discolored urine
  • Extreme fatigue
  • Loss of appetite
  • Vomiting

Symptoms can last from five to 10 days. An E. coli infection is usually not a serious health risk.

Some people who become infected with STEC develop a condition called hemolytic uremic syndrome (HUS). This is a potentially life-threatening illness that can affect the kidneys. Symptoms of HUS include infrequent urination, fatigue, and pale-looking skin. These patients need to be hospitalized because their kidneys may stop working.

What causes an E. coli infection?

The most common cause of an E. coli infection is contact with human or animal feces (the bacteria is found in stools). This contact can come about in several different ways, including the following:

  • Working with animals such as cows, goats, and sheep
  • Eating undercooked meat or raw vegetables (Meat can become contaminated with E. coli during the slaughtering process.)
  • Drinking unpasteurized milk or contaminated water (for example, drinking lake water while swimming)
  • Contact with the feces of infected people (for example, while changing a diaper)
  • Unsafe and improper food preparation (not washing hands before cooking food, unclean work surfaces in the kitchen)

In addition, E. coli infections can be spread from person to person in settings such as a day care center or a nursing home.

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E. coli

How Is E. coli Infection Diagnosed?

E. coli is diagnosed by testing a person’s stool for E. coli bacteria.

How Is E. coli Infection Treated?

Most people recover from E. coli infection without treatment within five to 10 days. Antibiotics should not be used to treat this infection because they may lead to kidney complications. Antidiarrheal treatments should also be avoided.

People who develop hemolytic uremic syndrome (HUS) are usually treated in the intensive care unit (ICU) with blood transfusions and kidney dialysis.

How Can E. coli Infection Be Prevented?

There are a number of simple ways in which E. coli infection can be prevented.

Wash Your Hands

  • Regularly and thoroughly wash your hands after going to the bathroom, changing diapers and before handling or eating food. It is especially important that people, particularly children, with diarrhea wash their hands thoroughly after going to the bathroom to prevent spreading infection.
  • Wash your hands after contact with farm animals, animal feces and being in farm environments.

Cook and Eat Food That Has Been Appropriately Prepared

  • Thoroughly cooking meat, especially ground beef, can destroy E. coli bacteria. Ground beef should be cooked until it is no longer pink and juices run clear. When cooking hamburgers, the meat thermometer should read 160 degrees in the thickest part of the hamburger patty and the patty should not be pink inside.
  • When eating in a restaurant, order your hamburger medium or well-done. Make sure ground beef is thoroughly cooked and hamburgers are not pink in the middle.
  • Thoroughly wash raw fruits and vegetables before eating.
  • Defrost food in the refrigerator, in cold water or in the microwave. Food should be stored in a refrigerator that is 40 degrees Fahrenheit or a freezer that is 0 degrees Fahrenheit or colder.

Keep Your Kitchen and Food Preparation Areas Clean

  • Thoroughly wash hands, counters, cutting boards, utensils and meat thermometers after use with hot soapy water.
  • Never place cooked hamburgers or ground beef on the unwashed plate that held the raw patties.
  • Keep raw meats separate from ready-to-eat foods.

Do Not Drink Unpasteurized Milk, Juice or Cider

  • Unpasteurized milk, juice and cider may contain E. coli. To be safe, drink only pasteurized beverages and juice concentrates.

Drink Municipal Water That Has Been Treated With Chlorine or Another Effective Disinfectant

  • Avoid swallowing lake or pool water when swimming.
  • Anyone with diarrhea should not swim in public pools or lakes, share baths with others or prepare food for others to prevent spreading infection.

Stay Informed

During an E. coli outbreak, such as the current spinach outbreak, stay informed of current Food and Drug Administration (FDA) or Centers for Disease Control and Prevention (CDC) recommendations. Presently, eating raw spinach is not recommended. Boiling fresh spinach or cooking fresh spinach until it reaches 160 degrees, usually for 15 seconds or more, will kill E. coli bacteria.

More Information

For more information on E. coli infection, please visit the Food and Drug Administration (FDA) Web site at www.fda.gov or Centers for Disease Control and Prevention (CDC) Web site at www.cdc.gov.

E. coli


Escherichia coli (E. coli) is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless. Some strains however, such as Shiga toxin-producing E. coli (STEC), can cause severe foodborne disease. It is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products, raw milk, and contaminated raw vegetables and sprouts.

STEC produces toxins, known as Shiga-toxins because of their similarity to the toxins produced by Shigella dysenteriae. STEC can grow in temperatures ranging from 7 °C to 50 °C, with an optimum temperature of 37 °C. Some STEC can grow in acidic foods, down to a pH of 4.4, and in foods with a minimum water activity (aW) of 0.95.

STEC is destroyed by thorough cooking of foods until all parts reach a temperature of 70 °C or higher. E. coli O157:H7 is the most important STEC serotype in relation to public health; however, other serotypes have frequently been involved in sporadic cases and outbreaks.


Symptoms of the diseases caused by STEC include abdominal cramps and diarrhoea that may in some cases progress to bloody diarrhoea (haemorrhagic colitis). Fever and vomiting may also occur. The incubation period can range from 3 to 8 days, with a median of 3 to 4 days. Most patients recover within 10 days, but in a small proportion of patients (particularly young children and the elderly), the infection may lead to a life-threatening disease, such as haemolytic uraemic syndrome (HUS). HUS is characterized by acute renal failure, haemolytic anaemia and thrombocytopenia (low blood platelets).

It is estimated that up to 10% of patients with STEC infection may develop HUS, with a case-fatality rate ranging from 3 to 5%. Overall, HUS is the most common cause of acute renal failure in young children. It can cause neurological complications (such as seizure, stroke and coma) in 25% of HUS patients and chronic renal sequelae, usually mild, in around 50% of survivors.

Persons who experience bloody diarrhoea or severe abdominal cramps should seek medical care. Antibiotics are not part of the treatment of patients with STEC disease and may possibly increase the risk of subsequent HUS.

Sources and transmission

Most available information on STEC relates to serotype O157:H7, since it is easily differentiated biochemically from other E. coli strains. The reservoir of this pathogen appears to be mainly cattle. In addition, other ruminants such as sheep, goats, deer are considered significant reservoirs, while other mammals (such as pigs, horses, rabbits, dogs, and cats) and birds (such as chickens and turkeys) have been found infected.

E. coli O157:H7 is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk. Faecal contamination of water and other foods, as well as cross-contamination during food preparation (with beef and other meat products, contaminated surfaces and kitchen utensils), will also lead to infection. Examples of foods implicated in outbreaks of E. coli O157:H7 include undercooked hamburgers, dried cured salami, unpasteurized fresh-pressed apple cider, yogurt, and cheese made from raw milk.

An increasing number of outbreaks are associated with the consumption of fruits and vegetables (including sprouts, spinach, lettuce, coleslaw, and salad) whereby contamination may be due to contact with faeces from domestic or wild animals at some stage during cultivation or handling. STEC has also been isolated from bodies of water (such as ponds and streams), wells and water troughs, and has been found to survive for months in manure and water-trough sediments. Waterborne transmission has been reported, both from contaminated drinking-water and from recreational waters.

Person-to-person contact is an important mode of transmission through the oral-faecal route. An asymptomatic carrier state has been reported, where individuals show no clinical signs of disease but are capable of infecting others. The duration of excretion of STEC is about 1 week or less in adults, but can be longer in children. Visiting farms and other venues where the general public might come into direct contact with farm animals has also been identified as an important risk factor for STEC infection.


The prevention of infection requires control measures at all stages of the food chain, from agricultural production on the farm to processing, manufacturing and preparation of foods in both commercial establishments and household kitchens.


The number of cases of disease might be reduced by various mitigation strategies for ground beef (for example, screening the animals pre-slaughter to reduce the introduction of large numbers of pathogens in the slaughtering environment). Good hygienic slaughtering practices reduce contamination of carcasses by faeces, but do not guarantee the absence of STEC from products.

Education in hygienic handling of foods for workers at farms, abattoirs and those involved in the food production is essential to keep microbiological contamination to a minimum. The only effective method of eliminating STEC from foods is to introduce a bactericidal treatment, such as heating (for example, cooking or pasteurization) or irradiation.


Preventive measures for E. coli O157:H7 infection are similar to those recommended for other foodborne diseases. Basic good food hygiene practice, as described in the WHO “Five keys to safer food”, can prevent the transmission of pathogens responsible for many foodborne diseases, and also protect against foodborne diseases caused by STEC.

The five keys to safer food are:

  • Keep clean.
  • Separate raw and cooked.
  • Cook thoroughly.
  • Keep food at safe temperatures.
  • Use safe water and raw materials.
  • Five keys to safer food manual

Such recommendations should in all cases be implemented, especially “cook thoroughly” so that the centre of the food reaches at least 70 °C. Make sure to wash fruits and vegetables carefully, especially if they are eaten raw. If possible, vegetables and fruits should be peeled. Vulnerable populations (such as small children and the elderly) should avoid the consumption of raw or undercooked meat products, raw milk, and products made from raw milk.

Regular hand washing, particularly before food preparation or consumption and after toilet contact, is highly recommended, especially for people who take care of small children, the elderly or immunocompromised individuals, as the bacterium can be passed from person to person, as well as through food, water and direct contact with animals.

A number of STEC infections have been caused by contact with recreational water. Therefore, it is also important to protect such water areas, as well as drinking-water sources, from animal waste (4).

Producers of fruits and vegetables

WHO’s “Five keys to growing safer fruits and vegetables” provides rural workers who grow fresh fruits and vegetables for themselves, their families and for sale in local markets, with key practices to prevent microbial contamination of fresh produces during planting, growing, harvesting and storing.

The five keys to growing safer fruits and vegetables are:

  • Practice good personal hygiene.
  • Protect fields from animal faecal contamination.
  • Use treated faecal waste.
  • Evaluate and manage risks from irrigation water.
  • Keep harvest and storage equipment clean and dry.
  • Five keys to growing safer fruits and vegetables

WHO response

WHO provides scientific assessments to control STEC in food. These assessments serve as the basis for international food standards, guidelines, and recommendations developed by the Codex Alimentarius Commission.

WHO promotes the strengthening of food safety systems by promoting good manufacturing practices and educating retailers and consumers about appropriate food handling and avoiding contamination.

During E. coli outbreaks, such as the those in Europe in 2011, WHO supports the coordination of information sharing and collaboration through International Health Regulations and the International Food Safety Authorities Network (INFOSAN) worldwide. WHO works closely with national health authorities and international partners, providing technical assistance and the latest information on outbreaks.

  • Outbreaks of E. coli in Europe

The Connection Between E. coli and Urinary Tract Infections (UTIs)

How Does E. coli Enter the Urinary Tract?

E. coli naturally resides in the intestines of all humans, usually doing no harm. But some E. coli are pathogenic, meaning they can cause illness. With UTIs, the E. coli bacteria from the intestines is present in fecal matter. And trace amounts of said fecal matter make their way into the urinary tract through the urethra opening and begin to multiply, according to an article published in June 2012 in the journal Expert Review of Vaccines. (6)

One of the reasons that women are more prone to urinary tract infections is that they have very short urethras. The E. coli bacteria from the rectum does not have a long distance to travel to reach the urethra and then bladder to cause an infection. (5)

Some common ways in which this migration or infection can happen include:

  • Sexual Contact A woman’s urethra is located next to the vagina and anus. This design makes it very easy for bacteria to move into the urinary tract during sexual intercourse and sexual contact.
  • Improper Wiping For women, wiping from back to front after a bowel movement can drag E. coli directly into the urethra. Because of this, it’s always recommended to wipe from front to back.
  • Holding Urine Frequent bathroom use allows the body to continue to flush bacteria such as E. coli from the system. This is especially important before and after intercourse. To encourage frequent urination, drink plenty of water throughout the day. (5)

In addition, there are other factors that elevate your risk of developing a UTI. These include:

  • Menopause It’s thought the hormone estrogen helps to protect against urinary tract infections. During menopause, estrogen is low, making menopausal women more susceptible to UTIs. (5)
  • Birth Control For women, the use of diaphragms as well as condoms with spermicidal foam is associated with a greater risk of getting a UTI. The former pushes on the urethra, making it harder to completely empty the bladder of bacteria, while the latter can kill good bacteria that protect from UTIs. (7,8)
  • Diabetes Those with high blood sugar are not able to fight off germs and bacteria as well as others, making them more prone to UTIs. (9)
  • Pregnancy From week 6 through week 24 of pregnancy, hormonal changes make it easier for bacteria such as E. coli to travel into the urinary tract. In addition, a growing uterus puts pressure on the bladder, making it more difficult to completely empty. (10)
  • Potty Training While UTIs in children peak in infancy (often due to anatomic abnormality), they peak again between ages 2 and 4, coinciding with potty training. In this scenario, withholding urine and poor wiping likely contribute to UTIs. (11)
  • Enlarged Prostate Gland This puts extra pressure on the bladder, which prevents it from emptying properly and flushing the system of E. coli. (5)
  • A Spinal Cord Injury This type of nerve damage prevents an individual’s ability to completely empty their bladder, thereby allowing the E. coli bacteria to multiply. (5)
  • Kidney Stones Having kidney stones or a condition that blocks the urinary tract can trap urine in the bladder and contribute to UTI infection. (5)

Is E. coli the cause of your UTI?

Bacteria causing your UTIs can include E. coli and K. pneumoniae

According to a 2012 report in the Journal of infectious diseases, Escherichia coli or E.coli, is responsible for over 85% of all urinary tract infections. Other bacteria that can cause UTIs include Klebsiella pneumoniae and Staphylococcus saprophyticus. If you’re always asking yourself, “why do I keep getting UTIs ?”, it’s highly likely these bacteria are the culprits. This article will discuss how these bacteria cause UTIs as well as tips for prevention.

Why is E.coli the most common offender?

E.coli is a bacteria that lives in our intestines. However, certain strains of this bacteria are pathogenic, which cause illnesses. When a stool makes its way through your large intestine and out of your anus, it makes the perineum (that area between your anus and your vulva) a reservoir for pathogenic bacteria such as E. coli. Bacteria then spread to the the opening of the urinary tract (your urethra). It can adhere to the urethra tube itself, causing urethritis, or to the bladder, causing cystitis. Both urethritis and cystitis are lower urinary tract infections. For women, the urethra is situated within close proximity to the anus. Although the urethra is meant to carry urine from the bladder out of the body, women have shorter ones than men do, which shortens the distance bacteria must travel to reach the bladder.

Other bacteria that can cause UTIs:

Staphylococcus saprophyticus is another common culprit of urinary tract infections. S. saprophyticus is a component of our normal flora that colonizes the perineum, rectum, urethra, cervix, and gastrointestinal tract. S. saprophyticus is a common gastrointestinal flora in pigs and cows which can be transferred to humans through eating these respective foods.

Klebsiella pneumoniae is a bacterium that usually lives in your intestines, where it does not cause disease or infections. However, if K. pneumoniae gets into other areas, it can cause pneumonia, meningitis, wound infections and urinary tract infections. A K.pneumoniae infection is normally contracted in a hospital/ health care setting from contaminated breathing tubes, or catheter tubes. People with compromised immune systems like diabetes, or people undergoing a procedure are more prone to contracting a K.pneumoniae infection.

How do you lower the risk of getting a UTI?

Bathroom activity:

  • Wipe front to back to keep fecal matter away from your urethra.
  • Pee when your bladder is full: don’t hold it in. Bacteria multiplies the longer urine is held in your bladder.
  • Avoid baths, showers are best.
  • Don’t douche or use feminine sprays.

Sexual activity:

  • Urinate after you have sex. If you don’t have to go right away, drink a glass of water. It’s important to pee after sex because this is one way to flush out any bacteria that may have spread to your urethra during intercourse.
  • Avoid switching to vaginal intercourse right after anal sex. This directly introduces fecal bacteria to your vagina and urethra. Always change the condom or make sure you and your partner wash the area with mild soap and water before mixing it up.
  • Clean your sex toys with mild, fragrance-free soap.
  • Use other birth control methods other than diaphragms.
  • Avoid spermicidal jelly.

Last but not least: Drink plenty of water.

UTIs are caused by bacteria that naturally exist within our bodies’ microbiome. Because of this, it seems like UTIs are inescapable. If you’re doing everything in your power to prevent UTIs naturally, but you’re still having problems, Uqora is an effective and safe way to keep UTIs away.

Intestinal E. Coli Infections

Escherichia coli (E. coli) are bacteria that are all around you. You can find E. coli everywhere in your environment, including on your skin and in your intestines. Most strains of E. coli are harmless but some strains can make you very sick and can cause sepsis. (Read about a 2018 food-borne E. coli outbreak here: E. Coli Outbreak Associated With Romaine Lettuce Still Active)

Sometimes incorrectly called blood poisoning, sepsis is the body’s often deadly response to infection. Sepsis kills and disables millions and requires early suspicion and treatment for survival.

Sepsis and septic shock can result from an infection anywhere in the body, such as pneumonia, influenza, or urinary tract infections. Worldwide, one-third of people who develop sepsis die. Many who do survive are left with life-changing effects, such as post-traumatic stress disorder (PTSD), chronic pain and fatigue, organ dysfunction (organs don’t work properly) and/or amputations.

How Is E. Coli Spread?

An E. coli infection can be spread from person to person and from animal to person, or you can contract the infection by touching a contaminated object or consuming contaminated food or drink.

The type of E. coli infection we may be most familiar with is often referred to as travelers’ diarrhea. This type of infection is caused by the enterotoxigenic E. coli (ETEC) bacteria. These bacteria produce substances that are toxic to intestinal cells. The toxins stimulate the intestinal wall lining, which then produces more fluid and this in turns causes diarrhea. Travelers may get the infection by drinking unclean water or eating food that hasn’t been properly prepared. Closer to home, there are often reports in the news of E. coli outbreaks or recalls for processed foods that may be contaminated with the bacteria.

Food and water:

  • Contaminated ground beef is one of the most common causes of E. coli infection. Thorough cooking will kill the bacteria.
  • E. coli bacteria found either on a cow’s udder or on milking equipment can get into raw milk. Pasteurizing the milk will kill the bacteria.
  • Fresh produce can be contaminated with E. coli as it comes in touch with the runoff from cattle farms. The bacteria can also be transferred to fresh produce during harvesting and packing, if the workers or the equipment carry the bacteria.
  • Human and animal feces may pollute ground and surface water.

Personal contact

  • People can spread E. coli bacteria. It can easily travel from person to person if someone has the bacteria on their hands, most often when infected adults and children don’t wash their hands properly. Children who visit petting zoos and animal barns can also contract the infection after touching the animals.

Symptoms of E. Coli Infection

The symptoms of an E. coli infection can be much more serious among infants and seniors, as well as people who are already ill. It can take anywhere from one to seven days for the symptoms to appear after you’ve been exposed to the bacteria. The most commonly known symptoms are severe abdominal cramping and watery or bloody diarrhea. Others include:

  • Nausea
  • Vomiting
  • Headache
  • Mild fever

Most healthy people recover from an E. coli infection in a week or so. However, young children and seniors, as well as anyone who is medically fragile can become very ill quite quickly. The diarrhea and vomiting can cause dehydration. If you are experiencing severe diarrhea and/or vomiting, consult with your doctor or nurse practitioner as soon as possible.

E. coli infection can also lead to a life-threatening complication of the kidneys called hemolytic uremic syndrome. If you experience any of these symptoms, see your doctor or go to an emergency department immediately:

  • Decreased urine output
  • Unexplained bruises
  • Unusual bleeding
  • Extreme fatigue

E. coli infection can lead to sepsis, so it is important to watch for the signs and symptoms of sepsis, particularly among seniors:


There is no treatment for E. coli infection yet. Treatment focuses on staying hydrated and resting. If necessary, your doctor may recommend IV fluids for hydration. It may be tempting to take an anti-diarrhea medication, but if you have an E. coli infection, this could slow down your body’s efforts to naturally expel the toxin so check with your doctor first. There are no antibiotics for most E. coli infections.

If you have contracted traveler’s diarrhea, your doctor may recommend that you do take anti-diarrhea medications for a short period or bismuth subsalicylate (Pepto-Bismol). In some instances, antibiotics may be prescribed.

Not all infections can be prevented, but the chances of developing an E. coli infection are lower if you follow these tips:

  • Cook all meat thoroughly, particularly ground beef or meet that has been mechanically tenderized.
  • Don’t reuse cutting boards or utensils after using them for meat products unless they’ve been washed in hot, soapy water first.
  • Drink only pasteurized milk and eat pasteurized dairy products.
  • Wash all fruits and vegetables thoroughly.
  • Wash your hands thoroughly, especially after touching animals and before and after handling food.

To reduce the risk of contracting travelers’ diarrhea while in countries where the bacteria is more common:

  • Drink bottled water and use bottled water to brush your teeth
  • Do not eat undercooked foods.
  • Do not use ice cubes made with tap water
  • Eat fruits that you can peel yourself
  • Wash your hands frequently

If you suspect sepsis, call 9-1-1 or go to a hospital and tell your medical professional, “I AM CONCERNED ABOUT SEPSIS.”

Updated December 13, 2017

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