What is Shiga toxin-producing Escherichia coli (STEC)?

From the Guidelines

Treatment for STEC infections should primarily focus on supportive care with fluid and electrolyte replacement, as antibiotics are generally not recommended and may increase the risk of developing hemolytic uremic syndrome (HUS) 1. The management of STEC infections is crucial to prevent complications and improve patient outcomes.

• Key aspects of treatment include:
  • Maintaining hydration with oral rehydration solutions or intravenous fluids in severe cases
  • Avoiding antimotility agents like loperamide, which can prolong toxin exposure
  • Implementing preventive measures, such as thoroughly cooking meat, washing fruits and vegetables, avoiding unpasteurized dairy products, practicing good hand hygiene, and preventing cross-contamination during food preparation
• STEC produces Shiga toxins that can damage the intestinal lining and enter the bloodstream, potentially causing HUS, characterized by hemolytic anemia, thrombocytopenia, and acute kidney injury 1.
• Most STEC infections resolve within 5-7 days, but close monitoring is essential, especially in children under 5 and the elderly, who are at higher risk for complications 1.
• Early identification of STEC infections is important to reduce the risk of complications and person-to-person transmission, and can be achieved through culture and detection of Shiga toxin or the genes that encode this toxin family 1.
• The use of antibiotics, such as fluoroquinolones, β-lactams, TMP-SMX, and metronidazole, should be avoided in patients with STEC O157 infections and likely non-O157 STEC infections that produce Shiga toxin 2, due to evidence of harm 1.

From the Research

Definition and Causes of STEC

• Shiga toxin-producing Escherichia coli (STEC) is a type of bacteria that can cause severe diseases, such as hemorrhagic colitis and hemolytic uremic syndrome (HUS) 2, 3, 4.
• STEC infection can be transmitted through the consumption of undercooked meat, pasteurized dairy products, contaminated vegetables, fruits, and water, or by contact with STEC diarrhea 3.

Symptoms and Diagnosis of STEC

• The symptoms of STEC infection include bloody diarrhea, hemolytic anemia, thrombocytopenia, and acute kidney injury (AKI) 2, 3.
• The diagnosis of STEC infection can be made through direct isolation of the bacteria from stool samples, or through indirect methods such as molecular, phenotypic, and serological tests 4.

Treatment and Management of STEC

• The treatment of STEC-HUS is challenging, and early diagnosis is crucial for improving prognosis and reducing mortality and sequelae 2.
• The management of STEC-HUS includes supportive care, such as volume expansion, renal replacement therapy (RRT), and transfusions of packed red blood cells and platelets 2, 3.
• The use of antibiotics in STEC infections is not recommended, as it may increase the risk of developing HUS 5.
• Immunomodulatory treatment with the selective cytopheretic device (SCD) has shown promise in treating STEC-HUS-induced AKI 6.

Complications and Outcomes of STEC

• STEC-HUS can lead to severe complications, including neurological complications, pancreatic, skeletal, and myocardial involvement, and even death 2, 3.
• The mortality rate of HUS is reported to be 3-5%, and about 12% of patients may progress to end-stage renal failure within four years 3.
• Long-term complications of STEC-HUS include hypertension, proteinuria, renal insufficiency, and insulin-dependent diabetes mellitus 3.