1. Department of Medicine (Infectious Diseases), Rush University Medical Center, Chicago, Illinois, USA
2. Department of Pathology, Rush University Medical Center, Chicago, Illinois, USA
3. Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA
4. Hospital Corporation of America, Nashville, Tennessee, USA
5. Division of Internal Medicine, Texas A&M Health Science Center College of Medicine, Houston, Texas, USA
6. Cook County Health and Hospitals System, Chicago, Illinois, USA
7. Office of HAI Prevention Research and Evaluation, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
8. Division of Infectious Diseases, University of California—Irvine School of Medicine, Orange, California, USA