Received Jul 15, 1996; accepted Mar 4, 1997.
,
, and
From the * Epidemic Intelligence Service and the Division of
Field Epidemiology, Epidemiology Program Office, and the
Foodborne
and Diarrheal Diseases Branch, National Center for Infectious Diseases,
Centers for Disease Control and Prevention, Atlanta, Georgia; the
§ Department of Pediatrics, University of Washington School of
Medicine, Seattle, Washington; the
Washington State Department of
Health, Seattle, Washington; the ¶ Department of Microbiology,
University of Washington School of Medicine, Seattle, Washington; and
the # Children's Hospital and Medical Center, Seattle, Washington.
Objective. To evaluate risk factors for progression of Escherichia coli O157:H7 infection to the hemolytic uremic syndrome (HUS).
Study Design. We conducted a retrospective cohort study among 278 Washington State children <16 years old who developed symptomatic culture-confirmed E coli O157:H7 infection during a large 1993 outbreak. The purpose of the study was to determine the relative risk (RR) of developing HUS according to demographic characteristics, symptoms, laboratory test results, and medication use in the first 3 days of illness.
Results. Thirty-seven (14%) 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, in the first 3 days of illness, use of antimotility
agents (odds ratio [OR] = 2.9; 95% confidence interval [CI]
1.2-7.5) and, among children <5.5 years old, vomiting (OR = 4.2;
95% CI 1.4-12.7). Among the 128 children tested, those whose white
blood cell (WBC) count was
13 000/µL in the first 3 days of
illness had a 7-fold increased risk of developing HUS (RR 7.2; 95% CI
2.8-18.5). Thirteen (38%) of the 34 patients with a WBC count
13 000/µL developed HUS, but only 5 (5%) of the 94 children whose
initial WBC count was <13 000/µL progressed to HUS. Among children
who did not develop HUS, use of antimotility agents in the first 3 days
of illness was associated with longer duration of bloody diarrhea.
Conclusions. 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. These data argue against the use of antimotility agents in acute childhood diarrhea. Our finding that no intervention decreased HUS risk underscores the importance of preventing E coli O157:H7 infections.
Key words: antibiotics, antimotility agents, Escherichia coli O157:H7, kidney failure, leukocytosis.