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Escherichiosis (coli-infection)
Last reviewed: 05.07.2025
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Escherichia coli (syn. Escherichioses, coli infection, coli enteritis, traveler's diarrhea) is a group of bacterial anthroponotic infectious diseases caused by pathogenic (diarrheagenic) strains of Escherichia coli, occurring with symptoms of general intoxication and gastrointestinal damage.
ICD-10 codes
- A04.0. Enteropathogenic escherichiosis.
- A04.1. Enterotoxigenic escherichiosis.
- A04.2. Enteroinvasive escherichiosis.
- A04.3. Enterohemorrhagic escherichiosis.
- A04.4. Escherichiosis of other pathogenic serogroups.
Epidemiology of Escherichiosis
Escherichia coli are normal inhabitants of the gastrointestinal tract. Enterotoxigenic and enteropathogenic strains are major causes of infantile diarrhea and traveler's diarrhea in adults. Enterohemorrhagic strains of Escherichia coli, such as type 0157:H7, produce cytotoxins, neurotoxins, and enterotoxins, including Shiga toxin, and are therefore capable of causing bloody diarrhea, which may progress to hemolytic uremic syndrome in 2% to 7% of cases. These strains are most commonly acquired by humans from eating undercooked beef. Other strains of enteroaggregative Escherichia coli require urgent consideration as potential important causes of persistent diarrhea in patients with AIDS and in children living in tropical regions.
When normal intestinal anatomical barriers are damaged (eg, by ischemia, irritable bowel syndrome, trauma), E. coli may disseminate to underlying structures or enter the bloodstream. The most common extraintestinal site of infection is the genitourinary tract, where infection usually ascends from the perineum. Hepatobiliary, peritoneal, skin, and pulmonary infections may also occur. E. coli bacteremia may occur without an obvious portal of infection. E. coli bacteremia and meningitis are common in neonates, especially premature infants.
Although more than 100 serotypes of E. coli produce Shiga toxin and related toxins, E. coli 0157:H7 is the most common in North America. In some parts of the United States and Canada, E. coli 0157:H7 infection may be a more common cause of bloody diarrhea than shigellosis and salmonellosis. Infection can occur in people of any age, but severe cases are most common in children and the elderly. E. coli 0157:H7 originates from ruminants, so outbreaks and sporadic cases have occurred with the consumption of undercooked beef (especially ground beef) or unpasteurized milk. Food or water contaminated with cow manure or raw ground beef may also spread the infection. MO can also be transmitted by the feco-oral route (especially among infants wearing diapers).
After entering the human gastrointestinal tract, E. coli 0157:H7 and similar strains of E. coli (called enterohemorrhagic E. coli) produce large quantities of various toxins in the lumen of the colon. These toxins are similar to the potent cytotoxins produced by Shigella dysenteriae type 1, Vibrio cholerae, and other enteropathogens. These toxins have been found to directly damage mucosal cells and vascular endothelial cells in the intestinal wall. When absorbed, they have a toxic effect on the endothelial cells of other vessels, such as the renal vessels.
[ What causes E. coli?
E. coli is the most numerous type of microorganism inhabiting the large intestine. Certain strains are capable of producing toxins that cause diarrhea. In addition, all strains are capable of causing infection when they enter sterile tissue. Diagnosis of E. coli is based on standard culture techniques. In cases of diarrhea, toxin testing may be useful. Antibiotic treatment is determined by susceptibility testing.
Escherichia coli 0157:H7 usually causes acute bloody diarrhea and, occasionally, hemolytic uremic syndrome. Symptoms of coliform infection include cramping abdominal pain and diarrhea that may be profusely bloody. Fever is low in this infection. Diagnosis is by stool culture and toxin testing. Treatment to support antibiotic therapy is discussed.
What are the symptoms of escherichiosis?
Escherichia coli infection due to Escherichia coli O157:H7 usually begins acutely with cramping abdominal pain and watery diarrhea, which may be accompanied by copious amounts of blood within 24 hours. Some patients describe the diarrhea as blood without stool, which has led to the term hemorrhagic colitis. Fever is usually absent or low-grade. Occasionally, the temperature may rise spontaneously to 102.4 F (39 C). In uncomplicated infections, diarrhea may last 1-8 days.
In approximately 5% of cases (mostly in children under 5 years of age and adults over 60 years of age), a complication called hemolytic uremic syndrome occurs, which typically occurs in the 2nd week of the disease. With or without this complication, there may be a fatal outcome, especially in the elderly.
Where does it hurt?
What's bothering you?
How is Escherichiosis diagnosed?
Samples of blood, stool or other clinical material are sent for culture. If an enterohemorrhagic strain is suspected, the laboratory must be notified, as this variant of infection requires a special nutrient medium for detection.
Coliform escherichiasis due to E. coli O157:H7 must be differentiated from other infectious diarrhea by isolating these organisms from stool cultures. Often, the clinician must request the laboratory to look for this organism specifically. Because bloody diarrhea and acute afebrile abdominal pain may have various noninfectious etiologies, E. coli O157:H7 infection should be considered when ischemic colitis, intussusception, and inflammatory bowel syndrome are suspected. Rapid stool testing for Shiga toxin may aid in the diagnosis. Patients at risk for noninfectious diarrhea may require barium enema. Barium enema may reveal erythema and edema of the sigmoid colon; barium enema usually shows edema, with a thumbprint sign.
What do need to examine?
What tests are needed?
How is Escherichiosis treated?
Escherichia coli is treated empirically and subsequently modified based on susceptibility testing. Many E. coli strains are resistant to penicillin and tetracyclines, so other antibiotics must be used, including ticarcillin, piperacillin, cephalosporins, aminoglycosides, trimethoprim-sulfamethoxazole, and fluoroquinolones. Surgery may be required to drain pus, clear necrotic lesions, and remove foreign bodies.
Treatment for this infection is generally supportive. Although E. coli is sensitive to the most commonly used antimicrobials, antibiotics do not affect the evolution of symptoms, elimination of carriage, or prevention of hemolytic uremic syndrome. In addition, fluoroquinolones are suspected of promoting the release of enterotoxin.
One week after infection, patients at high risk for developing hemolytic uremic syndrome (eg, children <5 years and the elderly) should be evaluated for early signs such as proteinuria, hematuria, red blood cell debris, and elevated serum creatinine. Edema and hypertension develop later. Patients with complications are likely to require intensive care, including dialysis and other specific therapies, in a third-tier medical center.
How to prevent escherichiosis?
E. coli can be prevented by properly cleaning the stool of infected individuals, maintaining good hygiene, and thoroughly washing hands with soap. Prevention measures that may be effective in day care settings include separating infected and uninfected children into separate groups or allowing infected children to attend after two negative stool cultures. Pasteurization of milk and thorough cooking of beef are effective in preventing foodborne transmission. It is important to report cases of bloody diarrhea to public health authorities, as timely intervention may prevent new cases.