Incidence of and Risk Factors for Infection or Colonization of Vancomycin-Resistant Enterococci in Patients in the Intensive Care Unit

Sung-Ching Pan,Jann-Tay Wang,Yin-Yin Chang,Shan-Chwen Chang,Mei-Ling Chen,Yee-Chun Chen,Jorge If Salluh

doi:10.1371/journal.pone.0047297

Abstract

The prevalence of vancomycin-resistant enterococci (VRE) colonization or infection in the hospital setting has increased globally. Many previous studies had analysed the risk factors for acquiring VRE, based on cross-sectional studies or prevalent cases. However, the actual incidence of and risk factors for VRE remain unclear. The present study was conducted in order to clarify the incidence of and risk factors for VRE in the intensive care unit (ICU). From 1st April 2008 to 31st March 2009, all patients admitted to a surgical ICU (SICU) were put on active surveillance for VRE. The surveillance cultures, obtained by rectal swab, were taken on admission, weekly while staying in the SICU, and on discharge from the SICU. A total of 871 patients were screened. Among them, 34 were found to carry VRE before their admission to the SICU, and 47 acquired VRE during their stay in the SICU, five of whom developed VRE infections. The incidence of newly acquired VRE during ICU stay was 21.9 per 1000 patient-days (95% confidence interval [CI], 16.4–29.1). Using multivariate analysis by logistic regression, we found that the length of ICU stay was an independent risk factor for new acquisition of VRE. In contrast, patients with prior exposure to first-generation cephalosporin were significantly less likely to acquire VRE. Strategies to reduce the duration of ICU stay and prudent usage of broad-spectrum antibiotics are the keys to controlling VRE transmission.

Highlights

Since 2003, vancomycin-resistant enterococci (VRE) have been one of the most important nosocomial pathogens in the United States of America (USA) [1]
The number of patients hospitalized for treatment of VRE infections doubled between 2003 and 2006, and, according to data collected from the National Nosocomial Infections Surveillance System from 1998 to 2002, VRE isolates make up 12.8% of enterococcal isolates recovered from patients in the intensive care unit (ICU), 12% of isolates recovered from nonICU patients, and 4.7% of isolates recovered from outpatients in the USA [1]
Prior usage of first-generation cephalosporin was negatively associated with VRE colonization

Summary

Introduction

Since 2003, vancomycin-resistant enterococci (VRE) have been one of the most important nosocomial pathogens in the United States of America (USA) [1]. The number of patients hospitalized for treatment of VRE infections doubled between 2003 and 2006, and, according to data collected from the National Nosocomial Infections Surveillance System from 1998 to 2002, VRE isolates make up 12.8% of enterococcal isolates recovered from patients in the intensive care unit (ICU), 12% of isolates recovered from nonICU patients, and 4.7% of isolates recovered from outpatients in the USA [1]. Several studies have demonstrated that patients with VRE bacteraemia have a higher mortality rate than those infected with vancomycin-susceptible enterococci [4,5,6].

Methods

Results

Conclusion