Shiga toxin‑producing Escherichia coli (STEC) is a fundamentally important foodborne zoonotic pathogen, commonly linked to severe gastrointestinal illness and critical complications like Hemolytic Uremic Syndrome (HUS). The term "STEC" encompasses variants such as EHEC (enterohemorrhagic E. coli), VTEC (verotoxigenic E. coli), among others—all producing Shiga toxins (Stx1, Stx2) that devastate human tissues.
- STEC is classically known as the “hamburger disease” due to its association with undercooked ground beef, but contamination sources also include unpasteurized dairy, fresh produce (like sprouts, lettuce, spinach), apple juice or cider not pasteurized, and untreated water.
- In Montreal, the average annual incidence over the past five years is 32 reported cases per year.
- Vulnerable groups include :
-Children under 5,
-Pregnant women,
-Adults aged 60 and above,
-Immunocompromised individuals
- Complications :
-Overall case fatality is just under 1%
Pathogenesis, Clinical Presentation & Virology
- STEC resides primarily in the intestinal tracts of ruminants like cattle, goats, sheep—often without symptoms
- Transmission to humans occurs through:
-Contaminated food,
-Waterborne exposure,
-Direct contact with infected persons or animals CDC+2PMC+2CDPH.
- Clinical onset typically occurs 3–4 days post-exposure, presenting with severe (often bloody) diarrhea, abdominal cramps, and sometimes vomiting—with fever generally low or absent New York State Department of Health+3CDPH+3Illinois Department of Public Health+3.
- HUS (hemolytic uremic syndrome) is the most serious outcome—characterized by hemolytic anemia, thrombocytopenia, and acute kidney failure—with risk highest in young children and older adults
Incidence, Serotypes & Diagnostics
In the United States:
STEC O157 causes an estimated 97,000 illnesses, 3,270 hospitalizations, and 30 deaths annually;
Non‑O157 STEC causes about 169,000 illnesses and 400 hospitalizations.
Under‑detection is common, as many cases go unreported due to lack of healthcare seeking or diagnostic testing.
Diagnoses rely on stool culture and toxin gene detection (e.g., via PCR to detect stx1, stx2 genes) .
Prevention & Management Strategies
Prevention (Public Health & Consumer Level)
Regulatory and industrial controls: Food safety measures in processing, handling, and quality of agricultural products santepubliquemontreal.caHealth Promotion Office.
Consumer guidelines:
Cook ground meats to ≥160 °F,
Avoid raw or unpasteurized dairy/juice,
Wash produce thoroughly,
Practice safe cross‑contamination avoidance (e.g., separate utensils for raw meat) Virginia Department of Health+2PMC+2.
Clinical Care
Supportive care remains central—hydration is critical.
Antidiarrheal medications (e.g., loperamide) and antibiotics are contraindicated, as they may worsen prognosis or increase risk of HUS.
Prompt medical attention is necessary for bloody diarrhea or signs of systemic involvement.