1. Aix-Marseille University (Aix-Marseille School of Economics); CNRS and EHESS, Centre de la Vieille Charité; 13236 Marseille, Cedex 2 France
2. INSERM-IRD-Aix-Marseille University; Faculty of Medicine, Aix-Marseille School of Economics (AMSE), SESSTIM-UMR 912; 13006 Marseille France
3. National AIDS Control Committee; Yaoundé Cameroon