1. School of Medicine, Creighton University, Omaha, NE 68178, USA
2. Department of Clinical Research & Public Health, School of Medicine, Creighton University, Omaha, NE 68178, USA
3. Division of Hematology/Oncology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
4. Division of Infectious Diseases, Department of Internal Medicine, School of Medicine, Creighton University, CHI Health, Omaha, NE 68124, USA