1. Global Center for Health Security, University of Nebraska Medical Center , Omaha, Nebraska , USA
2. College of Public Health, University of Nebraska Medical Center , Omaha, Nebraska , USA
3. Biocontainment Unit, Johns Hopkins University , Baltimore, Maryland , USA
4. Department of Hospital Epidemiology, Cedars-Sinai Medical Center , Los Angeles, California , USA
5. College of Allied Health, University of Nebraska Medical Center , Omaha, Nebraska , USA