A comparative review: Chronic Kidney Disease of unknown etiology (CKDu) research conducted in Latin America versus Asia

The incidence of chronic kidney disease of unknown or uncertain etiology (CKDu) is recognized as a global non-communicable health crisis. The goal of this work is to compare the types of research studies in Latin America and Asia, two regions with increasing CKDu incidence. A comparative literature review was conducted to evaluate the CKDu research design for peer-reviewed articles published from 2015 to 2019. Full texts were reviewed to identify study location, study type, study design, risk factors evaluated, and if applicable, sample type and number. In Asia and Latin America, 82 and 65 articles were identified in total, respectively, with 55 field studies in Asia versus 34 in Latin America. In Asia, research was focused on drinking water (34), heavy metals (20), and agrochemical product usage (19) as potential risk factors. In Latin America, research focused mostly on heat stress/dehydration (36) and agrochemical product usage (18) as potential CKDu risk factors. Biological samples were collected more frequently than environmental samples, especially in Latin America. Research to pinpoint the risk factors associated with CKDu to date is not standardized and typically limited in geographical scope. The emphasis of CKDu research varies by geographic region, with a greater priority placed on water quality and chemical exposure in Asia, versus dehydration and heat stress in Latin America. Using a harmonized approach to CKDu research would yield improved understanding of the risk factors associated with CKDu and how they compare across affected regions.