Drinking and recreational water have been carriers in several outbreaks, supposedly from fecal contamination by infected animals or people. It is quite tolerant of acid, salt and dry conditions, especially at refrigeration temperatures. It is, however, easily destroyed by heat. The very young and very old are most vulnerable to long-term complications. Initial symptoms generally occur within one to two days of eating the contaminated food, although periods up to three to five days have been reported.
Bloody diarrhea is accompanied by severe abdominal pain and moderate dehydration.
HUS symptoms include weakness, low red blood cell counts, lack of urine formation, swelling and acute renal failure. It most often is seen in children under the age of 10. About half of HUS patients require dialysis, and the mortality rate is 3 to 5 percent. Approximately 15 percent of the cases lead to chronic kidney failure. The development of insulin-dependent diabetes is another potential complication.