Genomic approaches have demonstrated significant capacity to inform the diagnosis, control, and basic biological understanding of long-established vector-borne diseases such as malaria, and newer diseases that have graduated from regionally to global concerns such as Zika. This Project will use genomic data to inform intervention strategies for vector-borne diseases at all stages of development, from the level of basic biology and therapeutic target ID (Aim 1), to data collection for disease elimination strategy development (Aim 2), to providing real-time situational awareness of an active disease elimination campaign and novel circulating viruses (Aim 3). Specific Aim 1: Identify host determinants of malaria infection through base-editing screens. We will functionally explore human red blood cell polymorphisms using state-of-the-art CRISPR base-editing tools to produce a library of red blood cells expressing known and candidate malaria-protective polymorphisms. We will further use precision base-editing to functionally evaluate each codon of the basigin invasion receptor using existing and engineered polymorphisms, given that the parasite ligand to this receptor (PfRH5) is an important vaccine target. We will measure the efficiency with which parasites invade edited red blood cells in pooled assays. Specific Aim 2: Define the pre-elimination genomic epidemiology of malaria in Mesoamerica We will sequence several hundred P. falciparum and P. vivax clinical specimens from Guatemala, Honduras, and Panamá. Integration of these data with the thousands of South American parasite genomes we have produced under the current GCID award will identify the impact of regional human migration on MesoAmerican malaria transmission, highlight potential shifts in drug sensitivity, and inform regional elimination plans. Specific Aim 3: Deploy molecular xenomonitoring of filaria and arboviruses in Guyana We will survey Aedes and Culex mosquitoes collected in Guyana for filarial worms using targeted genomic assays to test the hypothesis that mosquito xenomonitoring is more sensitive to residual transmission than human serological surveys. We will additionally perform viral metagenomic sequencing of mosquito salivary glands to characterize the abundance of known and novel vertebrate viruses. Impact: This work will employ innovative genomic approaches to inform short term and long term control strategies for malaria, the most significant vector-borne disease, and will further develop new methodologies for supporting filarial worm eradication and detection of novel vector-borne diseases that warrant future surveillance to prevent wider spillover.