2313. Risk of Relapsed or Persistent Infection Caused by Enterobacter Species in Children

BACKGROUND: Enterobacter species are a major cause of infections in hospitalized children. Treatment is complicated by the presence of a chromosomal AmpC β-lactamase, capable of inactivating certain antibiotics, including third-generation cephalosporins (3GC). Previous studies in adults have reported a 3–19% risk of relapsed bacteremia with 3GC therapy. Data in children regarding risk factors predicting relapse or persistence of infection are lacking. We sought to determine the frequency of and risk factors for relapse or persistence of Enterobacter infection in children. METHODS: Retrospective study of patients <21 years old admitted to Texas Children’s Hospital during 2012, 2015 and 2016 with bacteremia due to Enterobacter species. Risk factors for relapse or persistence of bacteremia 72 hours and up to 30 days after initial positive blood culture were evaluated; relapsed infection at secondary sites also was evaluated. RESULTS: 58 individual patients with bacteremia due to Enterobacter species were identified; most (58%) were immunosuppressed and 19 (32.8%) were critically ill. The majority (75.9%) had primary bacteremia; 82.8% had a central line. An intra-abdominal source was identified in 6 (10.3%) patients. Seventeen (29.3%) patients had initial Enterobacter isolates resistant to 3GCs. Of the 41 patients with 3GC-susceptible isolates, 5 (12.2%) had relapse or persistence of infection; 2 of these developed relapse with an isolate resistant to 3GCs. Among the relapsed cases, those who developed resistant isolates had uncontrolled intra-abdominal or biliary sources of infection. Treatment with a 3GC was not associated with increased risk of relapse or persistence of infection (OR 2.1; 95% CI, 0.3–14.2, P = 0.45). Source control was inadequate in all cases of relapsed bacteremia. Relapsed cases with primary bacteremia cleared their bacteremia with central line removal. One patient with relapsed infection died. CONCLUSION: The incidence of relapsed or persistent Enterobacter infection after initial bacteremia is comparable to previous adult studies. However, treatment of 3GC-susceptible isolates with 3GCs did not result in higher rates of treatment failure. Source control is important in preventing relapse or persistence of infection. DISCLOSURES: All authors: No reported disclosures.