Print E-mail
Volume 44, Number 2, April 2011

Risk factors and outcomes of carbapenem-nonsusceptible Escherichia coli bacteremia: A matched case–control study

Hong-Jyun Chang, Po-Chang Hsu, Chien-Chang Yang, An-Jing Kuo, Ju-Hsin Chia, Tsu-Lan Wu, Ming-Hsun Lee

Received: February 8, 2010    Revised: April 21, 2010    Accepted: June 22, 2010   


Corresponding author:

Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, 5 Fu-Shin Street, Gueishan 333, Taoyuan, Taiwan.
E-mail address: (M.-H. Lee).


Background and purpose: 

Infections due to carbapenem-resistant Enterobacteriaceae have been the emerging problem worldwide. This primary object of this study was to understand the risk factors and clinical outcomes of carbapenem-nonsusceptible Escherichia coli (CNSEc) bacteremia.




We conducted a matched case–control study in a 3,715-bed tertiary care medical center in northern Taiwan. The controls were selected among patients with carbapenem-susceptible E coli and were matched with CNSEc for bacteremia.



Fifty-one patients were included in this study (17 cases and 34 controls). Bivariate analysis showed that prior exposure to carbapenems (p<0.001), stay in intensive care units (p=0.016), placement of central venous catheters (p=0.001), chronic liver diseases (p<0.001), uremia with regular dialysis (p=0.004), and mechanical ventilation (p=0.004) were associated with CNSEc bacteremia. Multivariate analysis revealed that prior exposure to carbapenems [odds ratio (OR), 29.17; 95% confidence interval (CI), 1.76–484.70; p=0.019], uremia with regular dialysis (OR, 98.58; 95% CI, 4.02–999; p=0.005) and chronic liver diseases (OR, 27.86; 95% CI, 2.31–335.83; p=0.009) were independent risk factors for CNSEc bacteremia. Compared with carbapenem-susceptible E coli group, CNSEc group had a longer hospital stay (68.4 days vs. 35.8 days; p=0.04) and a higher disease severity, as indicated by a Pittsburgh bacteremia score greater than or equal to 4 (5.6% vs. 2.5%; p=0.015). Patients with CNSEc bacteremia had a higher overall in-hospital mortality rate (94.12% vs. 50.00%; p=0.002), but there was no difference in the 28-day mortality between these two groups.



CNSEc bacteremia would lead to a poor outcome among patients with prior exposure to carbapenems, chronic liver disease, and uremia with regular dialysis.



Key words:

Bacteremia, Carbapenem nonsusceptible, Escherichia coli