1. Infectious Disease Section, Minneapolis Veterans Affairs Health Care System , Minneapolis, Minnesota , USA
2. Department of Medicine, University of Minnesota , Minneapolis, Minnesota , USA
3. Division of Global Migration and Quarantine, Centers for Disease Control and Prevention , Atlanta, Georgia , USA
4. Division of Infectious Diseases, Department of Medicine, University of Kansas Medical Center , Kansas City, Kansas , USA
5. Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Minnesota , Minneapolis, Minnesota , USA