Volume 4, Issue 4

Background. Chronic kidney disease of uncertain etiology (CKDu) is a leading cause of kidney failure among farming communities in the dry zone of Sri Lanka, but community-based estimates using confirmatory testing are limited. Methods. A cross-sectional survey was conducted in 2025 among adults aged 18–70 years engaged in agricultural work in 40 Grama Niladhari divisions of the Anuradhapura and Polonnaruwa districts, selected by two-stage cluster sampling. Participants completed a structured questionnaire and provided blood and urine samples. CKD was defined as an estimated glomerular filtration rate below 60 mL/min/1.73 m² or a urine albumin-to-creatinine ratio of 30 mg/g or more persisting for 3 months, and CKDu was defined with the national case definition. Associated factors were examined with multilevel logistic regression. Results. Of 3,200 adults invited, 2,946 (92.1%) participated. The prevalence of CKD was 12.3% (95% CI 10.8–13.8) and that of CKDu 9.1% (95% CI 7.8–10.4), and 82.5% of participants with CKDu were unaware of their disease. CKDu was more common in men (11.6% vs 6.2%) and increased with age. It was independently associated with drinking water from shallow dug wells (adjusted OR 2.04, 95% CI 1.47–2.83), low water intake during field work, long working hours in hot weather, agrochemical spraying without protective equipment and a family history of CKD (adjusted OR 2.37, 95% CI 1.75–3.21). Conclusions. CKDu affects about 1 in 11 agricultural workers in the North Central Province and is largely undiagnosed. Safe drinking water, measures to prevent heat stress and dehydration, protective equipment and community screening should be prioritized.