1. Division of Infectious Diseases, Department of Medicine, Stanford University, Stanford, CA, USA
2. Department of Medicine, University of Arizona, Tucson, AZ, USA
3. Department of Medicine, Creighton University, Omaha, NE, USA
4. Department of Medicine, Rochester General Hospital, Rochester, NY, USA
5. Section of Infectious Diseases, Michael E. DeBakey Veterans Affairs Medical Center Baylor College of Medicine, Houston, TX, USA
6. Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA