The last cases of E. coli O157 associated with eating at Wendy's restaurants became ill on August 25, 2000. There has been no evidence of transmission of E. coli O157 from Wendy's restaurants since that time. 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.