1. Epidemic Intelligence Service, Division of Scientific Education and Professional Development, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
2. Arkansas Department of Health, Little Rock, Arkansas, USA
3. Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
4. US Public Health Service, Rockville, Maryland, USA
5. Jefferson Regional Medical Center, Pine Bluff, Arkansas, USA
6. University of Arkansas for the Medical Sciences, Little Rock, Arkansas, USA