1. National Infectious Diseases Service, Specialty Care Services, Veterans Health Administration, US Department of Veterans Affairs , Washington, DC , USA
2. Lexington Veterans Affairs Healthcare System , Lexington, Kentucky , USA
3. Division of Infectious Diseases, Department of Internal Medicine, University of Kentucky School of Medicine , Lexington, Kentucky , USA
4. VA Salt Lake City Health Care System , Salt Lake City, Utah , USA
5. Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine , Salt Lake City, Utah , USA
6. University of Maryland School of Medicine , Baltimore, Maryland , USA
7. University of Iowa Healthcare , Iowa City, Iowa , USA
8. Cincinnati Veterans Affairs Healthcare System , Cincinnati, Ohio , USA
9. Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati School of Medicine , Cincinnati, Ohio , USA