1. 1Centers for Disease Control and Prevention, 1600 Clifton Road, MS C-23, Atlanta, Georgia 30333
2. 2New York State Department of Health, Emerging Infections Program, ESP, Corning Tower, Room 651, Albany, New York 12237
3. 3Connecticut Emerging Infections Program, 1 Church Street, 7th Floor, New Haven, Connecticut 06510
4. 4University of Colorado School of Public Health, University of Colorado, Denver–Anschutz Medical Campus, Building 500, Room W3146, 13001 East 17th Place, MS B119, Aurora, Colorado 80045, USA