1. Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
2. Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA
3. WDS, Inc., Decatur, Georgia, USA
4. Infectious Diseases Branch, Division of Communicable Disease Control, California Department of Public Health, Richmond, California, USA
5. Illinois Department of Public Health, Springfield, Illinois, USA
6. Maryland Department of Health, Baltimore, Maryland, USA
7. New Jersey Department of Health, Trenton, New Jersey, USA
8. New York State Department of Health, Albany, New York, USA
9. New York City Department of Health and Mental Hygiene, New York, New York, USA
10. Emerging and Acute Infectious Disease Unit, Texas Department of State Health Services, Austin, Texas, USA