1. Division of Infectious Diseases, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
2. Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
3. Division of Occupational and Environmental Medicine, Department of Emergency Medicine, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA
4. Division of Occupational and Environmental Medicine, Department of Emergency Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
5. Division of Geriatrics, Department of Medicine, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA
6. Division of Infectious Diseases, Department of Medicine, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA
7. Department of Pathology and Laboratory Medicine, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania, USA
8. Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
9. Division of Geriatrics, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA