1. Columbia University College of Physicians and Surgeons, New York, New York, USA
2. New York City Department of Health, New York, New York, USA
3. Wadsworth Center, New York State Department of Health, Albany, New York, USA
4. New York Blood Center, New York, New York, USA
5. Centers for Disease Control and Prevention, Atlanta, Georgia, USA
6. Columbia Presbyterian Medical Center, New York, New York, USA