1. Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, Montana , USA
2. Department of Internal Medicine, University of Utah Health , Salt Lake City, Utah , USA
3. Rocky Mountain Veterinary Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, Montana USA
4. Critical Care Medicine Department, Clinical Center, National Institutes of Health , Bethesda, Maryland , USA