E. coli O157:H7

Type: Bacterial

Geography: North America, Europe

Cases Per Year: 100,000

Fatality Rate: 1% to 3%

First Discovered: 1982 in Michigan and Oregon, United States  

E. coli O157:H7 is one of hundreds of strains of the bacterium E. coli. This strain produces a powerful Shiga-like toxin (STEC) and can cause severe illness. Symptoms of infection include severe diarrhea (often bloody) and abdominal cramps. Symptoms appear 2 to 5 days following infection. In children under 5 years old and the elderly, this strain of E. coli can cause Hemolytic Uremic Syndrome, which occurs in about 2% to 7% of E. coli O157:H7 infections. HUS occurs when the toxin destroys red blood cells, and can lead to kidney failure, neurologic damage, and in some cases, death. Symptoms usually last 5 to 10 days.

E. coli O157 lives in the intestines of healthy cattle and other animals and can be found in water, food, soil, or on surfaces that have been contaminated with animal or human feces. People can become infected by eating contaminated food, such as undercooked beef or raw produce (sprouts and lettuce), drinking unpasteurized milk or contaminated water, touching contaminated surfaces, engaging in contact with farm animals, and not washing hands after using the bathroom or changing diapers and then eating food.

STEC is heat-sensitive and is destroyed by thorough cooking of foods until all arts reach a temperature of 70 degrees C (158 degrees F) or higher.

Photo: E. coli bacteria cultured – Electron micrograph.