Some infected people may have mild diarrhea or no symptoms at all. Most identified cases develop severe diarrhea and abdominal cramps. Blood is often seen in the stool. Usually little or no fever is present. The symptoms appear about three days after exposure, with a range of one to nine days.
Most persons recover without antibiotics or other specific treatment within five to ten days.
There is no evidence that antibiotics improve the course of disease, and it is thought that treatment with some antibiotics may precipitate kidney complications. Hemolytic uremic syndrome is a life-threatening complication usually treated in an intensive care unit. Blood transfusions and kidney dialysis are often required. With intensive care, the death rate for hemolytic uremic syndrome is three to five percent. Do not eat undercooked hamburger or other ground beef products.