Factors associated with Vancomycin-resistant Enterococcus acquisition during a large outbreak

Between 2013 and 2014 a Vancomycin-resistant Enterococci (VRE) outbreak occurred in a teaching hospital in France. The outbreak was significant possibly due to the lack of implementation of recommended control measures. The aim of this study was to identify the effect of the lack of adherence to control measures for prevention of VRE acquisition in contact patients taking into account individual risk factors. Contact patients (first two months of the outbreak) with VRE acquisition were compared to patients without VRE acquisition (univariate and logistic regression), in terms of institutional characteristics (unit of hospitalization and isolation measures) and risk factors. Between December 2013 and February 2014, 282 contact patients were included in the study. The prevalence of VRE acquisition was 6.4% (18/282). Significant risk factors for VRE acquisition according to logistic regression analysis were; lack of isolation, hospitalization in the same hospital unit as a VRE carrier patient and lack of isolation (RR=856.8, p=0.001), hospitalization in a specific unit (RR=927.4, p=0.002), McCabe score equal to 2 (RR=5233.6, p=0.008), age (RR=1.2 by year, p=0.011), hemodialysis (RR=36.1, p=0.011), central venous catheter (RR=25.4, p=0.021) and surgery (RR=0.012, p=0.007). Antibiotic use was a significant risk factor for VRE acquisition using univariate analysis (p<10^-3). The findings confirm that the factors focused on by the study (lack of isolation and dedicated unit) had a significant effect on VRE acquisition as patient associated factors. It highlights the importance of observance of the guidelines.