1. Connecticut Emerging Infections Program, New Haven, Connecticut, USA;
2. Connecticut Department of Public Health, Hartford, Connecticut, USA;
3. Centers for Disease Control and Prevention, Atlanta, Georgia, USA;
4. California Department of Health Services, Berkeley, California, USA;
5. Oregon Department of Human Services, Portland, Oregon, USA;
6. Minnesota Department of Public Health, Minneapolis, Minnesota, USA;
7. Georgia Division of Public Health, Atlanta, Georgia, USA;
8. New York State Department of Health, Albany, New York, USA;
9. University of Maryland School of Medicine, Baltimore, Maryland, USA