Infection often leads to bloody diarrhea, and occasionally to kidney failure.
Most illness has been associated with eating undercooked, contaminated ground beef. Infection can also occur after drinking raw milk and after swimming in or drinking sewage-contaminated water. Because the organism lives in the intestines of healthy cattle, preventive measures on cattle farms and during meat processing are being investigated. Although most strains are harmless and live in the intestines of healthy humans and animals, this strain produces a powerful toxin and can cause severe illness. Since then, most infections have come from eating undercooked ground beef.