Risk factors and outcomes for bloodstream infections with extended-spectrum beta -lactamase-producing Klebsiella pneumoniae ; Findings of the nosocomial surveillance system in Hungary.

Risk factors for and outcomes of bloodstream infections (BSIs) caused by ESBL-producing and by ESBL-non-producing Klebsiella pneumoniae were compared in a four-year multicenter study in Hungary. One hundred ESBL-positive and one hundred ESBL-negative patients were included as cases and controls. Investigated risk factors were related to demographics, comorbid conditions, treatments, invasive procedures, surgery prior bacteremia, presence of additional nosocomial infections and preceding hospital admission within a year. Measured outcomes were crude mortality, mortality related to infection and delay in introducing appropriate therapy (DAT). Though some risk factors for infection (admission to intensive care units, having central venous and/or urinary catheter, mechanical ventilation) were shared by both groups, in other respects cases and controls were found to differ substantially. The 36 percent of patients with BSIs with ESBL-producing Klebsiella died versus 23 percent of controls (odds ratio [OR]: 2.5; 95% confidence interval [CI]: 1.0-5.4; p = 0.02). The 18 percent of deaths in cases versus 9% in controls could be attributed to infection (OR: 5.0; 95% CI: 1.5-16.2; p = 0.006). Cases more often received previous antibiotic therapy than controls (OR: 2.7; 95% CI: 1.1-6.7; p = 0.02) and delay in the introduction of appropriate antibiotic treatment was observed in 44% of cases versus 19% of controls (OR: 3.4; 95% CI: 1.6-7.3; p = 0.001). The results demonstrate that BSIs caused by ESBL-producing K. pneumoniae are related to previous antibiotic therapy and are associated with a high rate of mortality that is often linked to delay in the introduction of appropriate antibiotic therapy. This confirms that besides infection control measures the early identification and antibiotic resistance profiling of the infecting pathogen is salient in the control of BSIs caused by ESBL-producing K. pneumoniae .