1. Hospital Epidemiology and Infection Control Program, Yale-New Haven Hospital, New Haven, Connecticut, USA
2. Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
3. Northeast Medical Group, New Haven, Connecticut, USA
4. Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USA
5. Department of Diagnostic Radiology, Yale-New Haven Hospital, New Haven, Connecticut, USA
6. Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA