1. Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
2. Vanderbilt University School of Medicine, Nashville, Tennessee, USA
3. Public Health Division, Oregon Health Authority, Portland, Oregon, USA
4. Minnesota Department of Health, St Paul, Minnesota, USA
5. Emerging Infections Program, New York State Department of Health, Rochester, New York, USA
6. New Mexico Department of Health, Santa Fe, New Mexico, USA
7. Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
8. Emerging Infections Program, Emory University, Atlanta, Georgia, USA
9. Connecticut Department of Public Health, Hartford, Connecticut, USA
10. Colorado Department of Public Health and Environment, Denver, Colorado, USA
11. Emerging Infections Program, Oakland, California, USA