1. Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
2. City of Laredo Health Department, Laredo, Texas, USA
3. Secretaria de Salud, Mexico City, Mexico
4. University of Texas, Boerne, Texas, USA
5. Texas Department of Health, Laredo, Texas, USA
6. Secretaria de Salud de Tamaulipas, Nuevo Laredo, Tamaulipas, Mexico