Escherichia coli O157:H7 (E. coli O157)
E. coli O157:H7 is one of hundreds of strains of the bacterium Escherichia coli. 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.
E. coli O157:H7 and HUS Fact Sheet
Answers to frequently asked questions about E. coli O157:H7 and the complication Hemolytic Uremic Syndrome (HUS).
CDC: Answers to some common questions about E. coli.
Common symptoms include:
- severe bloody diarrhea
- abdominal cramps
- little or no fever
Other symptoms may include:
- nonbloody diarrhea
- or no symptoms at all.
Symptoms usually begin 2-5 days after infection (range, 1 to 8 days).
Duration of Illness
The illness usually resolves in 5 to 10 days.
Hemolytic Uremic Syndrome develops in about 5% of reported E. coli O157:H7 cases, most frequently in young children or the elderly.
- Many illnesses have been associated with eating undercooked, contaminated
- Produce items (e.g., lettuce, sprouts) can be contaminated through
contact with cattle feces in the field.
- Person-to-person contact in families and childcare centers is also
a common mode of transmission.
- Infection can also occur after drinking raw milk and after swimming in or drinking water contaminated by farm animals, usually cattle.
Do you suspect that you have a foodborne or waterborne illness? Visit reporting suspected foodborne/waterborne illnesses.