1. Department of Environmental, Agricultural and Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA
2. Global Center for Health Security, University of Nebraska Medical Center, Omaha, NE, USA
3. Department of Environmental and Occupational Health, Indiana University School of Public Health, Bloomington, IN, USA
4. Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA