Evolution of the nutritional status and factors associated with undernutrition in children under five of age between 2014 and 2017 in 24 health districts of Burkina Faso - T. Bernadette Picbougoum; M.A. Serge Somda; Isidore T. Traoré; Julia Lohmann; Manuela De Allegri; Hervé Hien; Nicolas Méda; Annie Robert (PLOS Global Public Health)