1. Department of Pediatrics, Amirou Boubacar Diallo National Hospital of Niamey, Niamey, Niger
2. Sciences of Health Faculty, Abdou Moumouni University of Niamey, Niamey, Niger
3. Faculty of Health Science, University of Zinder, Zinder, Niger
4. Centre de Recherche Médicale et Sanitaire (CERMES), Niamey, Niger