1. World Health Organization Regional Office for Africa, Brazzaville, Republic of Congo
2. Epidemic Intelligence Service, and, Atlanta, Georgia
3. Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
4. World Health Organization (WHO) Regional Office for Africa, Intercountry Support Team, Harare, Zimbabwe
5. WHO Regional Office for Africa, Intercountry Support Team, Ouagadougou, Burkina Faso
6. National Institute for Communicable Diseases, Johannesburg, South Africa
7. Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Banjul
8. WHO, Geneva, Switzerland