SRILANKAs CKD Unknown Etiology (CKDu) Article 01. Describing Natural History and Exploring Risk Factors for Kidney Function Decline in Persons With CKD of Uncertain Etiology in Sri Lanka Kidney International Reports 2023. 02.CKD of Unknown Etiology (CKDu) in Sri Lanka: A Multilevel Clinical Case Definition for Surveillance and Epidemiological Studies Kidney International Reports (2019). 03. Additional perspectives on chronic kidney disease of unknown aetiology (CKDu) in Sri Lanka – lessons learned.