1. Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
2. Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, Alabama, USA
3. Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
4. Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
5. Division of Infectious Diseases, University of Nebraska Medical Center, Omaha, Nebraska, USA