Craig S. Wong, Srdjan Jelacic, Rebecca L. Habeeb, Sandra L. Watkins, Phillip I. Tarr
E coli causes sporadic and epidemic gastrointestinal infections worldwide. In 15 percent of the children who are infected with E. coli O157:H7, the hemolytic-uremic syndrome develops soon after the onset of diarrhea. This syndrome is characterized by thrombocytopenia, hemolytic anemia, and nephropathy. Treatment with antibiotics does not ameliorate E. coli O157:H7 infections, and in some studies, it has been associated with worse clinical outcomes. Results from this most recent study confirm that administering sulfa-containing antibiotics to children infected with E. coli O157:H7 increases their risk of the hemolytic-uremic syndrome and indicate that (beta)-lactam antibiotics are associated with a similar degree of risk.
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.