Outcomes and characteristics of ertapenem-nonsusceptible Klebsiella pneumoniae bacteremia at a university hospital in Northern Taiwan: A matched case-control study

Background and purpose: Carbapenem-resistant Klebsiella pneumoniae is an emerging problem worldwide. The object of this study was to investigate the risk factors, characteristics and outcomes of ertapenem-nonsusceptible K pneumoniae (ENSKp) bacteremia. Methods: We conducted a 1:2 ratio matched case-control study. The controls were randomly selected among patients with ertapenem-susceptible K pneumonioe (ESKp) bacteremia and were matched with ENSKp cases for bacteremia. Results: Seventy-five patients were included in this study (25 cases and 50 controls). Bivariate analysis showed that prior exposure to either beta-Lactam/beta-Lactam-lactamase inhibitors (p = 0.008) or 4th generation cephalosporins (p < 0.001), chronic obstructive pulmonary disease (COPD) (p = 0.001), acute renal failure (p = 0.021), chronic kidney disease without dialysis (p = 0.021), recent hospital stay (p = 0.016), intensive care unit stay (p = 0.002), mechanical ventilation (p = 0.003), central venous catheter placement (p = 0.016), Foley indwelling (p = 0.022), polymicrobial bacteremia (p = 0.003) and higher Pittsburgh bacteremia score (p < 0.001) were associated with ENSKp bacteremia. The multivariate analysis showed that prior exposure to 4th generation cephalosporins (odds ratio [OR], 28.05; 95% confidence interval [CI], 2.92-269.85; p = 0.004), COPD (OR, 21.38; 95% CI, 2.95-154.92; p = 0.002) and higher Pittsburgh bacteremia score (OR, 1.35; 95% CI, 1.10-1.66; p = 0.004) were independent factors for ENSKp bacteremia. ENSKp bacteremia had a higher 14-day mortality rate than ESKp bacteremia (44.0% vs. 22.0%; p = 0.049). The overall in-hospital mortality rates for these two groups were 60.0% and 40.0% respectively (p = 0.102). Conclusion: ENSKp bacteremia had a poor outcome and the risk factors were prior exposure of 4th generation cephalosporins, COPD and higher Pittsburgh bacteremia score. Antibiotic stewardship may be the solution for the preventive strategy. Copyright (c) 2011, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved.