Evolution of chloroquine resistance rate and proportion of patients with CQ prescriptions between 1992 and 2004 in Niakhar area. Green line represents the proportion of patients receiving CQ prescriptions among all patients being prescribed anti-malarials (AM) (%). Red bars represent the rate of CQ resistance (%). (a) 1993, 1994, and 1995 estimates: in vivo chemosensitivity studies conducted in Diohine village, Niakhar area, Fatick region . (b) 1998 and 2001 estimates: in vivo studies conducted in Kaolack sentinel site, 50 kilometres from Fatick .