1. Centers for Disease Control and Prevention, Atlanta, Georgia, USA
2. Sacramento County Public Health Laboratory, Sacramento, California, USA
3. University of California Davis School of Medicine, Sacramento, California, USA
4. California Emerging Infections Program, Oakland, California, USA
5. Colorado Department of Public Health and Environment, Denver, Colorado, USA
6. Exempla St. Joseph Hospital, Denver, Colorado, USA
7. Connecticut Emerging Infections Program, New Haven, Connecticut, USA
8. Yale-New Haven Hospital, New Haven, Connecticut, USA
9. Children's Healthcare of Atlanta, Atlanta, Georgia, USA
10. Georgia Department of Public Health, Atlanta, Georgia, USA
11. State Hygienic Laboratory at the University of Iowa, Iowa City, Iowa, USA
12. Maryland Department of Health and Mental Hygiene, Baltimore, Maryland, USA
13. Minnesota Department of Health, St. Paul, Minnesota, USA
14. Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA