Escherichia coli (E. coli) are bacteria that live in the intestines of people and animals. Most E. coli are harmless and do not cause illness. Shiga toxin-producing E. coli (STEC) make toxins that can cause severe illness. STEC is commonly heard about in the news in association with foodborne outbreaks. The most commonly recognized STEC strain is E. coli O157:H7. Other STEC strains are commonly referred to as non-O157 STEC and may also cause foodborne illnesses.
Illnesses have been linked to consumption of food or drinks contaminated by animal feces, including undercooked ground beef, unpasteurized apple juice/cider, raw milk, produce, and flour, and recreational exposure in contaminated water. Person-to-person contact in families and childcare centers due to poor personal hygiene and inadequate hand washing can cause further transmission.