As summer approaches, emergency departments (EDs) often see an uptick in gastrointestinal illnesses related to recreational water activities. Recent incidents highlight the widespread nature of this issue – from the May 2024 E. coli outbreak in Lake Anna, Virginia to unacceptably high levels of E. coli in Paris’ Seine River in the run-up to the Summer Games. E. coli, particularly Shiga toxin-producing E. coli (STEC), can contaminate lakes, rivers, and other bodies of water through agricultural runoff and sewage overflow, putting swimmers at risk of infection. As ED physicians, it’s important to quickly identify and treat these infections, accurately distinguishing between mild cases and potentially life-threatening situations.
Clinical Presentation and Diagnosis
According to the Centers for Disease Control and Prevention, typical STEC infections from recreational waters typically present with symptoms similar to other gastrointestinal illnesses including:
- Diarrhea
- Abdominal pain
- Vomiting
- Low-grade to no fever
A stool culture is the routine diagnostic approach. Treatment focuses on supportive care including rest and hydration. Avoiding antibiotics is recommended as it can increase risk of more serious complications.
Severe Complication: Hemolytic Uremic Syndrome (HUS)
While many E. coli infections resolve without complications, ED physicians must be alert to signs of severe disease, particularly in high-risk groups. Hemolytic Uremic Syndrome (HUS) is a life-threatening complication of STEC infection, occurring in about 5-10% of cases, particularly in children under 5. As HUS can cause kidney damage and failure, early recognition is crucial. MedLine Plus outlines the red flags of HUS above and beyond the typical STEC symptoms:
Early symptoms:
- Bloody diarrhea and vomiting
- Fever
- Lethargy and weakness
Later symptoms:
- Severe dehydration including electrolyte imbalance and no to low urine output (extremely important in younger children and elderly)
- Severe abdominal pain or abdominal distension
- Decreased consciousness
- Skin pallor and rash (petechiae)
There is no specific diagnostic test for HUS. If HUS is suspected, additional tests are required beyond a stool sample in order to rule out other thrombocytopenic disorders. According to the Merck Manual, tests include:
- Complete blood count with platelets
- Urinalysis
- Peripheral blood smear
- Direct antiglobulin (Coombs) test
- LDH, prothrombin time (PT)
- Partial thromboplastin time (PTT)
- Fibrinogen test
Management and Treatment of HUS:
As outlined by the National Organization for Rare Disorders, treatment for HUS includes:
- Monitoring and management of fluid and electrolyte balance
- Control of hypertension
- Red blood cell transfusions
- Platelet transfusions (for active bleeding or before surgical procedures)
- Dialysis (for patients with kidney failure)
Conclusion
As summer approaches, emergency department physicians must remain vigilant for E. coli infections from recreational waters. While most cases resolve with supportive care, the potential for severe complications like Hemolytic Uremic Syndrome (HUS) requires a high index of suspicion and early intervention, especially in vulnerable populations. As ED physicians, we play a vital role in treating E. coli infections and ensuring patients receive the right care based on the severity of their case.
Responses