Prevalence and Risk Factors of Carbapenem-resistant Enterobacteriaceae Acquisition in an Emergency Intensive Care Unit in a Tertiary Hospital in Korea: a Case-Control Study

Abstract

Background: Infections caused by carbapenem-resistant Enterobacteriaceae (CRE) are associated with high mortality rates and their treatment is difficult because treatment is limited to certain antibiotics, such as colistin and tigecycline. We aimed to perform active surveillance culture of CRE (ASC-CRE) to monitor the prevalence of CRE acquisition during intensive care unit (ICU) care and to examine the potential risk factors associated with CRE acquisition.

Methods: We conducted ASC-CRE on patients who were admitted to the ICU in the emergency room at a tertiary hospital. Rectal swabs were analyzed using methods established by the Centers for Disease Control and Prevention. To detect carbapenemase-producing CRE, a polymerase chain reaction assay to detect five carbapenemase genes (bla_NDM, bla_KPC, bla_VIM, bla_IMP-1, and bla_OXA-48) was performed.

Results: There were 22 CRE acquisition in 21 patients (2.6%, 21/810) and the incidence of CRE acquisition was 4.3/1,000 person-days, respectively. The most common species detected was Klebsiella pneumoniae (72.7%, 16/22), and 9 carbapenemase-producing CREs (7 bla_KPC and 2 bla_NDM) were detected. Independent risk factors associated with CRE acquisition were men gender (adjusted odds ratio [aOR], 5.3; 95% confidence interval [CI], 1.3-21.3), history of admission within one year (aOR, 3.9; 95% CI, 1.2-12.1), co-colonization with multidrug-resistant Acinetobacter baumannii (aOR, 15.6; 95% CI, 3.6-67.8) and extended-spectrum β-lactamases-producing bacteria (aOR, 4.7; 95% CI, 1.5-14.6), and exposure to glycopeptide antibiotics (aOR, 3.6; 95% CI, 1.3-9.9).

Conclusion: The identification of patients with risk factors for CRE acquisition and early detection of CRE acquisition using ASC-CRE may be useful for CRE control.

Keywords: Carbapenem-Resistant Enterobacteriaceae; Incidence; Intensive Care Units; Risk Factors.

Fig. 1. Study design for the ASC-CRE among patients admitted to the EICU in an acute care hospital in non-endemic area.

CRE = carbapenem-resistant Enterobacteriaceae, ASC-CRE = active surveillance culture of carbapenem-resistant Enterobacteriaceae, EICU = emergency intensive care unit, PCR = polymerase chain reaction.

Fig. 2. Length of ICU stay from ICU admission to the 1st CRE detection (days) in patients with CRE acquisition.

ICU = intensive care unit, CRE = carbapenem-resistant Enterobacteriaceae.