Study site
The study was conducted in Kawthaung and Bokepyin townships of Kawthaung district,Tanintharyi Region. The study sites are located in the southern-most costal region of Myanmar bordering Thailand (Figure 1), where the local climate alternates between a cool-dry (December-March) and hot and humid-wet season (April-November), with a heavy torrential rain falls in May-September, providing a perfect favorable ground for breeding of malaria vectors. The study site was selected based on a strong suspicion of artesunate resistance [4], and on undocumented knowledge of a high population movement.