1. Centers for Disease Control and Prevention, Fort Collins, Colorado, USA;
2. New York State Department of Health, Albany, New York, USA;
3. New York City Department of Health, New York City, New York, USA;
4. Connecticut Department of Public Health, Hartford, Connecticut, USA;
5. New Jersey Department of Health and Social Services, Trenton, New Jersey, USA;
6. Massachusetts Department of Public Health, Boston, Massachusetts, USA;
7. Maryland Department of Health and Mental Health, Baltimore, Maryland, USA;
8. Pennsylvania Department of Health, Harrisburg, Pennsylvania, USA;
9. Armed Forces Medical Intelligence Center, Department of Defense, Fort Detrick, Maryland, USA