Extended-Spectrum ß-lactamase-producing enterobacteriaceae infections in children: A two-center case-case-control study of risk factors and outcomes in Chicago, Illinois

Background: Extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae infections are an emerging problem in children.We sought to identify risk factors and describe outcomes associated with pediatric ESBL-producing bacterial infections at 2 hospitals in Chicago, IL from 2008 to 2011. Methods: A case-case-control study of children aged 0-17 years was conducted. Cases of Escherichia coli, Klebsiella, and Proteus spp. ESBL-producing bacterial infections (n = 30) were compared to uninfected controls and in parallel, cases of non-ESBL-producing bacterial infections (n = 30) were compared to uninfected controls (n = 60).We then qualitatively compared these results. Results. Median age of cases was 1.06 years; 62% of isolates were from urine, and 60% were E. coli. By multivariable analysis, ESBL cases were 5.7 and 3.3 times more likely to have gastrointestinal (P = .001; 95% confidence interval [CI] 1.9-17.0) and neurologic (P = .001; 95% CI 1.1-3.7) comorbidities, respectively, than controls; non-ESBL cases were also more likely to have gastrointestinal comorbidities than controls (P = .014; odds ratio 3.6; 95% CI 1.2-10.1). Study period prevalence remained stable (1.7%). Most (60%) infections occurred in the intensive care unit; however, 30% of children presented in the outpatient setting. Seventy-seven percent of isolates were multidrug resistant (ie, resistant to ≥3 antibiotic classes). Recurrence of infection occurred in 17% of ESBL cases. Crude mortality rates (7%) did not differ between cases and controls. Conclusions. The incidence of pediatric infection due to ESBL-positive Enterobacteriaceae was stable at 2 large tertiary-care medical centers over a 4-year period. Multidrug resistance in pediatric ESBL isolates is common. Risk factors for infection due to ESBL-producing bacteria include neurologic medical conditions.