E. coli infection probably is not diagnosed or reported nearly as often as it occurs. Health officials in the United States estimate that the E. coli strain O157:H7 causes 73,000 infections and 61 deaths nationally each year.¹ Currently, most states require that all cases of severe bloody diarrhea (hemorrhagic colitis) be reported to their health departments to help identify outbreaks.

It is not known how common the infection is in other countries. Outbreaks in Canada, Japan, the United Kingdom, and other European countries suggest that E. coli O157:H7 infection is a worldwide problem.

Anyone who is exposed to disease-causing strains of E. coli bacteria can become infected, but the most serious infections occur among children younger than 5 and in older adults.¹