Predictors of hemolytic uremic syndrome in children during a large outbreak of Escherichia coli
Predictors of hemolytic uremic syndrome in children during a large outbreak of Escherichia coli O157:H7 infections. Bell BP, Griffin PM, Lozano P, Christie DL, Kobayashi JM, Tarr PI. Pediatrics Jul;100(1):E12.
In 1993, a large outbreak of E. coli O157:H7 infections resulted from the consumption of inadequately cooked hamburgers in a chain of restaurants in Washington State, resulting in more than 500 cases. This study was conducted among the cohort of children who sought medical attention during the outbreak to evaluate possible risk factors for progression of E. coli O157:H7 infection to hemolytic uremic syndrome (HUS). The study included 278 children under 16 years of age who developed symptomatic culture-confirmed E coli O157:H7 infection during the outbreak. Thirty-seven (14%) of the children developed HUS. In univariate analysis, no associations were observed between HUS risk and any demographic characteristic, the presence of bloody diarrhea or of fever, or medication use. In multivariate analysis, HUS risk was associated with the use of antimotility agents in the first three days of illness and, among children less than 5.5 years old, vomiting. Among the 128 children tested, those whose white blood cell (WBC) count was equal to or greater than 13,000/mL in the first three days of illness had a seven-fold increased risk of developing HUS. Thirteen (38%) of the 34 patients with a WBC count equal to or greater than 13,000/mL developed HUS, but only five (5%) of the 94 children whose initial WBC count was less than 13,000/mL progressed to HUS. Among children who did not develop HUS, use of antimotility agents in the first three days of illness was associated with longer duration of bloody diarrhea. These data argue against the use of antimotility agents in acute childhood diarrhea. Factors that reflect an early response to infection (vomiting and leukocytosis in the first three days of illness) predicted the subsequent development of HUS, so that the pathophysiologic processes resulting in HUS often are initiated by the time medical attention is initially sought. These findings underscore the importance of preventing E. coli O157:H7 infections. The authors suggest that prospective studies are needed to further evaluate measures to prevent the progression of E. coli O157:H7 infection to HUS and to assess further clinical and laboratory risk factors.