1. University of Utah School of Medicine , Salt Lake City, Utah , USA
2. Division of Infectious Diseases and Epidemiology, Department of Medicine, Intermountain Medical Center , Salt Lake City, Utah , USA
3. Department of Emergency Medicine, Intermountain Medical Center , Murray, Utah , USA
4. Department of Emergency Medicine, Stanford University , Palo Alto, California , USA
5. Department of Pulmonary and Critical Care Medicine, Intermountain Medical Center , Murray, Utah , USA
6. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Utah School of Medicine , Salt Lake City, Utah , USA