Chronic Interstitial Nephritis in Agricultural Communities (CINAC) in Sri Lanka

Abstract

A significant increase in cases of chronic kidney disease has been observed in the dry zone of Sri Lanka. This unusual chronic kidney disease was first reported in the early 1990s among middle-aged paddy farmers. Considering epidemiologic and histopathologic findings, the disease recently was named chronic interstitial nephritis in agricultural communities (CINAC). Twenty-five years after the first report, CINAC is the most significant public health issue in the paddy farming areas with more than 70,000 estimated patients and many deaths. Histopathologically, this disease is a tubular interstitial nephritis associated with glomerular sclerosis and mild vascular changes. Morphologic and biochemical characteristics of CINAC in Sri Lanka share many similarities with Mesoamerican nephropathy. Certain natural and man-made toxins, heat stress with repeated volume and salt depletion, infections such as hantavirus and leptospirosis, and a genetic origin have been proposed and investigated as possible etiologies, and an association between CINAC and herbicides is widely discussed. Several preventive measures already have been implemented by health authorities in Sri Lanka to minimize nephrotoxin exposure and well hydrate the inhabitants in the disease-endemic region. The impact of these interventions will be watched with anticipation.