1. Faculty of Sciences and Health Technics, Gamal Abdel Nasser University of Conakry, Conakry, Guinea
2. Pediatrics Department Kamsar Hospital, Kamsar, Guinea
3. Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
4. National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK
5. University of Medical Sciences Teaching Hospital, Akure, Nigeria