1. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland
2. Viollier AG, Basel, Switzerland
3. Institute for Infectious Diseases, University of Berne, Berne, Switzerland
4. University Clinic for Infectious Diseases, University Hospital and University of Berne, Inselspital, Berne, Switzerland
5. Division of Clinical Microbiology, University Hospital Basel, Basel, Switzerland