1. Infection Control Program, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
2. Department of Medicine, Division of Infectious Diseases, Evanston Northwestern Healthcare, Evanston, Illinois.
3. Department of Surgery, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
4. Department of Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa.
5. Department of Anesthesiology, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
6. Clinical Microbiology Laboratory, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.