2. Measure the frequencies of dihydrofolate reductase (dhfr), dihydropteroate synthetase (dhps), P. falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multi-drug resistant (pfmdr 1) genotypes and establish their relationship with in vivo resistance to SP (dhfr and dhps), CQ, AQ, SP/AQ, AQ/AS, SP/AS, and MQ.