1. 1 Department of Community Health, Ensign College of Public Health, Kpong, Ghana
2. 2 Department of Public Health, University of Ghana, Accra, Ghana
3. 3 Stop Polio Consultant, World Health Organization, Democratic Republic of the Congo
4. 4 Quality Directorate, Nyaho Healthcare Centre, Accra, Ghana
5. 5 Dubreka District Health Directorate, Ministry of Health and Public Hygiene, Conakry, Guinea