Risk Factors for Prolonged Carriage and Reacquisition of Vancomycin-resistant Enterococci

Abstract

Background: Patients infected with vancomycin-resistant enterococci (VRE) are kept in isolation to prevent the spread of VRE in medical facilities. However, decision-making regarding isolation can be challenging at the time of re-admission of previously VRE-colonized or infected patients who have not been examined for VRE infections for a long time. This study focused on providing guidelines for isolating VRE patients based on the analysis of risk factors for prolonged carriage and reacquisition of VRE. Methods: A retrospective review was performed on medical records of patients who were diagnosed with VRE infections at a university hospital in 2009. Durations of colonization and negative conversion of VRE were estimated by Kaplan-Meier methods. Prolonged duration of VRE infections and risk factors for reacquisition were analyzed using Cox’s proportional hazard model. Results: Among 220 VRE-colonized patients, 132 were cleared, and 30 reacquired after negative conversion of VRE. The median duration of colonization was 33.1 weeks, and the median clearance period was 19.4 weeks. Patients who were admitted via the emergency department and treated with glycopeptides tended to have prolonged duration of VRE colonization. Prolonged hospitalization and metronidazole therapy increased the risk of reacquisition more rapidly. Conclusion: Treatment with glycopeptides, metronidazole antibiotic therapy, history of admission via the emergency department, and prolonged hospitalization can affect to prolonged carriage and reacquisition of VRE. Consider carefully the release of isolation of VRE patients with these risk factors.