Treatment of Shiga Toxin-Producing E. coli (STEC) Infections
The primary treatment for STEC infection is aggressive supportive care with early parenteral volume expansion, while antibiotics should be avoided due to their association with increased risk of hemolytic uremic syndrome (HUS) and more severe disease. 1
Immediate Management Priorities
Fluid Resuscitation
- Initiate early parenteral volume expansion immediately upon diagnosis, as this may decrease renal damage and improve patient outcomes. 1
- Provide adequate intravenous rehydration based on severity of dehydration, particularly in high-risk groups including children under 5 years (who have the highest incidence and HUS risk). 1, 2
- Monitor and correct electrolyte abnormalities including potassium, sodium, calcium, and magnesium. 2
Critical Antibiotic Avoidance
- Do not administer antibiotics for STEC infections, as antibiotic therapy is associated with more severe disease and may increase the risk of HUS. 1, 3
- This contraindication exists because antibiotics can trigger increased Shiga toxin production and release from bacteria. 3, 4
- Prompt diagnosis is essential specifically to ensure antibiotics are not given. 1
Antimotility Agent Restrictions
- Avoid antimotility agents in children under 18 years with acute diarrhea, patients with inflammatory diarrhea, and those with confirmed or suspected STEC infection. 2
Diagnostic Timing Considerations
- Collect stool specimens as early as possible in the illness course, ideally before any antibiotic administration. 1
- Bacteria become difficult or impossible to detect after 1 week of illness, and Shiga toxin genes may be lost by the bacteria over time. 1
- Early detection is especially critical in children, who are most likely to develop HUS (approximately 8% of O157 STEC cases progress to HUS). 1
Monitoring for Complications
HUS Surveillance
- Monitor closely for development of HUS, particularly in children, characterized by thrombocytopenia, hemolytic anemia, and acute kidney injury. 1, 2, 5
- Strains producing Stx2 toxin (especially O157 STEC with stx2 and eae virulence genes) carry higher risk for severe disease and HUS. 1
- Detection of O157 STEC within 24 hours helps physicians rapidly assess risk for severe disease and initiate measures to prevent renal damage and death. 1
Renal Replacement Therapy
- Prepare for renal replacement therapy in severe cases where acute kidney injury develops. 5
Infection Control Measures
- Implement strict hand hygiene with soap and water after toilet use, diaper changes, before food preparation, and after handling soiled items. 2
- Use contact precautions with gloves and gowns when caring for patients with diarrhea. 2
- Notify local public health authorities immediately, as STEC infections are reportable diseases. 2
- Food handlers, healthcare workers, and childcare workers may require negative stool cultures before returning to work. 2
Special Population Considerations
High-Risk Patients
- Children aged <5 years have the highest incidence of STEC infection and greatest risk for HUS. 1
- Immunocompromised patients, elderly individuals, and those with significant comorbidities require more aggressive monitoring. 2
- Consider broader diagnostic testing and more intensive management in immunocompromised patients. 2
Hospitalized Patients
- STEC testing may not be warranted for patients hospitalized >3 days, as diarrhea is more likely from C. difficile in this setting. 1
- However, when admitted with diarrheal symptoms, STEC testing is appropriate regardless of hospitalization duration. 1
Emerging Therapeutic Approaches
While not yet standard of care, research is ongoing for:
- Monoclonal antibodies or antisera against Shiga toxin. 3
- Toxin receptor analogs (such as eliglustat, which reduces Shiga toxin binding to glomerular endothelial cells). 6, 3
- Plasma exchange in severe cases. 5
These experimental therapies remain investigational and should not replace the cornerstone of treatment: early aggressive fluid resuscitation and avoidance of antibiotics. 1, 3