Risk Factors for and Clinical Outcomes of Bloodstream Infections Caused by Extended-Spectrum-β-Lactamase-Producing Klebsiella Species in Children: Results of a 5 Year Study

Abstract

Aim: The extended-spectrum beta lactamase (ESBL) producing Klebsiella species causes widespread problems in intensive care units. The aim of this study was to define the risk factors and clinical outcomes associated with ESBL-producing Klebsiella spp. bloodstream infections in children.Material and Method: We conducted a case-control study between January 1, 2003 and December 31, 2007 at Uludag University Pediatric Clinic. All patients with ESBL-producing Klebsiella spp. bloodstream infections were compared to patients with non-ESBL-producing Klebsiella spp. bloodstream infections. Risk factors analyzed included prior antibiotic use, underlying diseases, invasive medical devices, and other demographic characteristics.Results: Klebsiella spp. bloodstream infections were diagnosed in 49 of the 10,258 patients hospitalized in our center between January 1, 2003 and December 31, 2007 (overall incidence, 4.7 per 1,000 admissions). Twenty-eight cases and 21 control subjects were included in the study. The mean age of patients was 23.3 +/- 34.9 months (2days-18 years) and 59.2% were male. Malignancy (32.7%) was the most common underlying disease in the patients with Klebsiella spp. bloodstream infections. The prevalence of ESBL-producing isolates among Klebsiella spp. was found to be 57.1 %. All of the ESBL-producing Klebsiella spp. were Klebsiella pneumoniae. In this study, risk factors for ESBL-producing Klebsiella spp. bloodstream infections included - previous therapy with broad-spectrum antibiotics, prolonged hospitalization, the presence of a central venous catheter, and total parenteral nutrition (p<0.05). Predisposing factors associated with mortality were; presence of septic shock, neurological disease, chronic hepatic disease, previous therapy with broad-spectrum antibiotics, mechanical ventilation, and presence of central venous catheter (p<0.05). All ESBL-producing isolates were susceptible to carbapenem antibiotics. The mortality rate was found to be 26.5% of all children with Klebsiella spp bloodstream infections in this study. Although a substantially higher proportion of children with ESBL-producing Klebsiella spp. died (in-hospital mortality: 35.7% vs 14.3%), this difference was not statistically significant (p>0.05).Conclusion: In this study, the prevalence of ESBL-producing isolates among Klebsiella spp. was 57.1%. Risk factors for ESBL-producing Klebsiella spp. bloodstream infections included previous therapy with broad-spectrum antibiotics, prolonged hospitalization, the presence of a central venous catheter, and total parenteral nutrition. Mortality rate for the patients in the ESBL group was 35.7% whereas it was 14.3% for the patients in the non-ESBL group.