1. Influenza Division, Centers for Disease Control and Prevention , Atlanta, Georgia , USA
2. California Emerging Infections Program , Oakland, California , USA
3. Colorado Department of Public Health and Environment , Denver, Colorado , USA
4. Connecticut Emerging Infections Program , New Haven, Connecticut , USA
5. Yale School of Public Health , New Haven, Connecticut , USA
6. Georgia Emerging Infections Program , Atlanta, Georgia , USA
7. Atlanta Veterans Affairs Medical Center , Atlanta, Georgia , USA
8. Emory University School of Medicine , Atlanta, Georgia , USA
9. Maryland Department of Health , Baltimore, Maryland , USA
10. Michigan Department of Health and Human Services , Lansing, Michigan , USA
11. Minnesota Department of Health , St. Paul, Minnesota , USA
12. New Mexico Department of Health , Albuquerque, New Mexico , USA
13. University of New Mexico Health Science Center , Santa Fe, New Mexico , USA
14. New York State Department of Health , Albany, New York , USA
15. University of Rochester School of Medicine and Dentistry , Rochester, New York , USA
16. Ohio Department of Health , Columbus, Ohio , USA
17. Oregon Health Authority , Portland, Oregon , USA
18. Vanderbilt University School of Medicine , Nashville, Tennessee , USA
19. Salt Lake County Health Department , Salt Lake City, Utah , USA