1. Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
2. World Health Organization, Dhaka 1212, Bangladesh
3. Rwanda Biomedical Centre, Ministry of Health, Kigali P.O. Box 7162, Rwanda
4. African Field Epidemiology Network, Kigali, Rwanda
5. Health Information Systems Program (HISP), Kigali, Rwanda
6. World Health Organization, Kigali P.O. Box 1324, Rwanda
7. National Stop Transmission of Polio (NSTOP) Program, African Field Epidemiology Network (AFENET), Abuja 900103, Nigeria
8. Division of Global Health Protection, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA