1. Department of Epidemiology, School of Public Health, Brown University, Providence, Rhode Island
2. Rhode Island Department of Health, Providence
3. Department of Population Health Sciences, Weill Cornell Medical College, New York, New York
4. Section of General Internal Medicine, Department of Medicine, Boston Medical Center, Boston, Massachusetts
5. Section of Infectious Diseases, Boston Medical Center, Boston, Massachusetts
6. Department of Medicine, Boston University School of Medicine, Boston, Massachusetts