E. coli O157 infection is characterized by the sudden onset of diarrhea and abdominal cramps. Blood may appear in the diarrhea 6-48 hours later. Nausea and vomiting are also commonly reported. Fever is generally absent or low-grade. HUS is characterized in the early stages by decreased urine output, pallor and lethargy.
Transmission is fecal-oral.
People with E. coli O157 infection are contagious from the time diarrhea begins and for up to four weeks thereafter. Asymptomatic infection also occurs. Transmission is interrupted by thorough hand-washing after defecation and thorough cleansing of food that will be eaten raw.