PROJECT SUMMARY/ABSTRACT This is an Administrative Supplement Application to carry out SARS-CoV-2 PCR testing in an existing NIAID- funded study (1K23AI143967) evaluating the clinical and economic impacts of influenza in Guatemalan agricultural workers. The Parent Study includes the enrollment of an existing cohort (n=2,706) of Guatemalan agricultural workers with high rates of chronic medical conditions (CMCs) into a prospective active surveillance system for cough and fever (severe acute respiratory illness [SARI]). Workers meeting the case definition are tested for influenza A/B and RSV (Roche cobas® Liat RT-PCR Assay) and then clinical and economic outcomes are assessed using follow up surveys and company reported absenteeism and productivity data. This Administrative Supplement will allow us to maintain our cough/fever surveillance system, given an increase in expected cases due to SARS-CoV-2, and to perform RT-PCR testing for SARS-CoV-2. We hypothesize that, similar to influenza, COVID-19 will place a significant clinical and economic burden on agricultural workers, especially the large proportion with CMCs, such as chronic kidney disease of unknown origin (CKDu, aka “Mesoamerican nephropathy”), given existing data showing a significantly increased risk of severe disease. Evaluating these outcomes in an existing prospective cohort will allow us to measure these burdens on a population-level, which will provide critical data in understanding the true impact of disease. We aim to implement our SARS-CoV-2 testing immediately, analyze and disseminate our results quickly, and make samples from our specimen biobank (annual blood and urine, acute illness respiratory and blood) available for additional research.