Risk Factors of Rectal Colonization of Vancomycin-Resistant Enterococci in Shiraz Namazi Hospital

Introduction: Risk factors for Vancomycin-resistant Enterococci (VRE) colonization are patient-related factors such as underlying disease or amount of prescribed antibiotics, and hospital-related factors such as duration of hospitalization, type of performed therapeutic procedures, and antibiotic prescription. This nested case control study was performed to determine risk factors of rectal VRE colonization at Shiraz Namazi Hospital. Methods: During December 2003 to July 2004 serial rectal swabs were yielded from all hospitalized patients every 5 days. Susceptibility of detected Enterococci was tested by Minimum Inhibitory concentration dilution method. Results: More than 1000 rectal swabs were taken. A total of 99 of 700 patients (14%) were colonized with VRE (cases) and 59 patients were colonized with Vancomycin-sensible strains (VSE), serving as controls. In the univariate analysis, history of antibiotic use (P=0.04), underlying disease (P=0.01), renal failure due to dialysis (P=0.03), use of vancomycin (P=0.04), use of third generation Cephalosporins (P=0.04), and duration of vancomycin therapy (>7 days) (p=0.02) showed statistically significant differences between the two groups. In the multivariate analysis (logistic regression), presence of underlying disease (OR, 2.43; 95% CI, 1.2 – 4.9; P=0.013) and duration of Vancomycin use (>7 days) were independently associated with VRE colonization. Conclusion: This study, which was the first study on the prevalence of VRE in Iran, demonstrated that VRE prevalence is high in Shiraz, and confirmed earlier observations regarding risk factors for VRE in other countries and determined risk factors that may be considered in interventional strategies for the control of VRE