1. Prospectively measure the in vivo response of P. falciparum malaria in Mali to several different antimalarial drugs and drug combinations: chloroquine (CQ), sulfadoxine-pyrimethamine (SP), amodiaquine (AQ), sulfadoxine-pyrimethamine in combination with amodiaquine (SP/AQ), amodiaquine in combination with artesunate (AQ/AS), sulfadoxine-pyrimethamine in combination with artesunate (SP/AS), and artemether-lumefantrine (Co-artem). In one site with preliminary data showing a high rate of P. falciparum resistance to mefloquine (MQ), this drug will also be tested.