title: The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections.
abstract: BACKGROUND
  Children with gastrointestinal infections caused by Escherichia coli O157:H7 are at risk for the hemolytic-uremic syndrome. Whether antibiotics alter this risk is unknown.
  
  
  METHODS
  We conducted a prospective cohort study of 71 children younger than 10 years of age who had diarrhea caused by E. coli O157:H7 to assess whether antibiotic treatment in these children affects the risk of the hemolytic-uremic syndrome and to assess the influence of confounding factors on this outcome. Estimates of relative risks were adjusted for possible confounding effects with the use of logistic-regression analysis.
  
  
  RESULTS
  Among the 71 children, 9 (13 percent) received antibiotics and the hemolytic-uremic syndrome developed in 10 (14 percent). Five of these 10 children had received antibiotics. Factors significantly associated with the hemolytic-uremic syndrome were a higher initial white-cell count (relative risk, 1.3; 95 percent confidence interval, 1.1 to 1.5), evaluation with stool culture soon after the onset of illness (relative risk, 0.3; 95 percent confidence interval, 0.2 to 0.8), and treatment with antibiotics (relative risk, 14.3; 95 percent confidence interval, 2.9 to 70.7). The clinical and laboratory characteristics of the 9 children who received antibiotics and the 62 who did not receive antibiotics were similar. In a multivariate analysis that was adjusted for the initial white-cell count and the day of illness on which stool was obtained for culture, antibiotic administration remained a risk factor for the development of the hemolytic uremic syndrome (relative risk, 17.3; 95 percent confidence interval, 2.2 to 137).
  
  
  CONCLUSIONS
  Antibiotic treatment of children with E. coli O157:H7 infection increases the risk of the hemolytic-uremic syndrome.
authors.affiliation: Children's Hospital and Regional Medical Center and the University of Washington School of Medicine, Seattle 98105, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Wong
authors.forename: S
authors.initials: S
authors.lastname: Jelacic
authors.forename: R L
authors.initials: RL
authors.lastname: Habeeb
authors.forename: S L
authors.initials: SL
authors.lastname: Watkins
authors.forename: P I
authors.initials: PI
authors.lastname: Tarr
mesh_terms: D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D002511:Cephalosporins / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D003967:Diarrhea / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D004927:Escherichia coli Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D019453:Escherichia coli O157; D005243:Feces / Q000382:microbiology; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000209:etiology*; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D011446:Prospective Studies; D012306:Risk; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D015662:Trimethoprim, Sulfamethoxazole Drug Combination