The most common symptom of O157 infection is bloody diarrhea. Hemorrhagic colitis is characterized by severe abdominal cramps, bloody stools, little or no fever, and evidence of erosion and hemorrhage of the colon. Initial symptoms usually occur one to two days after ingestion of contaminated food. The illness can last six to eight days and can be severe enough to result in hospitalization. About half of the HUS patients require dialysis, and 3 to 5 percent of HUS cases are fatal.
Complications can include seizures, stroke or coma.
This disease is primarily found in adults, particularly the elderly. The mortality rate of TTP can be as high as 50 percent. Most persons recover without antibiotics or other specific treatment in 5 to 10 days. There is no evidence that antibiotics improve the course of the disease, and it is thought that treatment with some antibiotics may precipitate kidney complica- tions. Hemolytic uremic syndrome is a life-threatening condition usually treated in an intensive care unit.