Malaria, caused by single cell Plasmodium parasites transmitted by Anopheline mosquitoes remains one of the most significant global public health challenges, and there are nearly 60,000 reported cases in Colombia each year. If Colombia is to move towards malaria elimination, we need to understand the true extent of malaria transmission and investigate the presence of antimalarial drug resistance in low transmission regions. This proposal brings together Colombian and UK partners spanning both academic research and public health agencies responsible for malaria control. It will utilise cutting edge technologies to understand parasite diversity and and transmission, in order to develop rational malaria preventive measures to help in the push towards elimination. We will focus on a malaria endemic region of Colombia with low-income and highly vulnerable populations, Guapi in the Pacific coast of the Cauca Department. Whole genome sequencing technologies will be used to establish for the first time the extent of genome variation in local strains of P.falciparum, the causative agents of malaria in Colombia, and to establish the extent of drug resistant alleles. In order to establish the true extent of malaria transmission in these regions, we will also obtain data on the proportion of individuals with asymptomatic malaria that constitute the reservoir for the propagation of infection. Together, this information will allow the design of preventive measures and the quantitative evaluation of the control effort in malaria endemic areas. This information will be made available to local and national public health information systems and the entire Malaria community through the MalariaGen (Genomic Epidemiology Network), to be used in epidemiological studies as well as the surveillance of drug resistant malaria.