Who gets HUS from E. coli 0157:H7?

We have an interesting patient on the service who has E. coli O157:H7. How can we predict who will get HUS?

I didn't find much on this question. A google scholar search for "predict HUS 0157" turned up this article. It is a quick and dirty study of 15 kids with 0157:H7, 5 with HUS, and 10 without. They looked at fever, vomiting, abdominal pain, tachycardia, and dehydration, and there was a significant p. value associated with dehyrdration at presentation and development of HUS.

Joishy, M. and Jauhari, P. and Mathew, A.A. and Rangarajan, T. "Can we predict the development of haemolytic uraemic syndrome in the early stage of Escherichia coli O157 infection?"Archives of Disease in Childhood, (2008) 93:2 180.

This article refers to this article, which is a nice review of 10 studies looking at the association between leukocytosis and development of HUS. A number of these studies were pediatric.
Anjay MA, Anoop P, Britland A, " Leukocytosis as a predictor for progression to haemolytic uraemic syndrome in Escherichia coli O157:H7 infection, 2007 Sep;92(9):820-3.

Cliff's:
Leukocytosis is a reliable early risk predictor
Absence of leukocytosis also has reliable NEGATIVE predictive value.