title: Non-linear significant relationship between use of glycopeptides and isolation of vancomycin-resistant Enterococcus species in a university hospital setting.
abstract: BACKGROUND
  Emergence of colonization and infection with vancomycin-resistant enterococci (VRE) has become a worldwide challenge. To investigate whether the increasing incidence of VRE isolation can be correlated with use of glycopeptides in the hospital setting, we conducted a hospital-wide two-year study in the university hospital of Vienna.
  
  
  METHODS
  Within the period from January 2011 through December 2012 all patients with isolation of invasive or non-invasive VRE were retrospectively included. Specialty-specific data concerning the consumption of vancomycin and teicoplanin, fluoroquinolones and third generation cephalosporins in defined daily doses (DDDs) from June 2010 through May 2012 were extracted from the hospital pharmacy computer system. To assess the relationship between the usage of those antibiotics and the incidence of VRE (VRE-rate per 10 000 patients) a Poisson regression was performed.
  
  
  RESULTS
  In the study period 266 patients were colonized or infected with VRE. Specialty-specific VRE isolation was as follows: general surgical units (44 patients), bone marrow transplant unit (35 patients), general medical units (33 patients), cardiothoracic surgery (27 patients), nephrology (26 patients), haematooncology (22 patients), gastroenterology (17 patients), urology (17 patients), and the infectious diseases unit (11 patients). Hospital-wide consumption of glycopeptides was higher for teicoplanin than for vancomycin (26 242 versus 8677 DDDs). Specialty-specific VRE incidence significantly increased with the use of glycopeptides, fluoroquinolones or third generation cephalosporins (p < 0.001). The results of the Poisson regression for vancomycin (p = 0.0018) and teicoplanin (p < 0.0001) separately were both highly significant. Spearman's correlation coefficient indicated a strong correlation between the two variables (rho = 0.8).
  
  
  CONCLUSIONS
  Overall usage of glycopeptides, fluoroquinolones or third generation cephalosporins contributed to the emergence of VRE in the hospital setting.
authors.affiliation: Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria ; Center for Infectious Diseases and Infection Control, Jena University Hospital, Jena, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Forstner
authors.affiliation: Department of Hospital Epidemiology and Infection Control, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Magda
authors.initials: M
authors.lastname: Diab-Elschahawi
authors.affiliation: Section for Medical Statistics, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Danijel
authors.initials: D
authors.lastname: Kivaranovic
authors.affiliation: Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Graninger
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Dieter
authors.initials: D
authors.lastname: Mitteregger
authors.affiliation: Hospital Pharmacy, General Hospital of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: Macher
authors.affiliation: Center of Medical Statistics, Informatics and Systems Intelligence, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wrba
authors.affiliation: Department of Hospital Epidemiology and Infection Control, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Presterl
keywords: Enterococcus faecalis; Enterococcus faecium; Fluoroquinolones; Glycopeptides; Third generation cephalosporins