Chronic Interstitial Nephritis in Agricultural Communities

Abstract

Chronic Interstitial Nephritis in Agricultural Communities (CINAC) has been increasingly recognized since the early 1990s. It has been called epidemic chronic kidney disease unknown cause (CKDu) in Sri Lanka, and meso-American nephropathy in Central America. CINAC occurs regionally in the Tropics, predominantly in rural/agricultural zones. It is increasingly recognized, but also believed to be increasing in incidence. Men are affected up to three times more often than women. Its incidence increases with age, and a number of other epidemiological factors impact on it. In some areas, such as the North Central Province of Sri Lanka and regions of Central America, it drives extreme rates of CKD and end-stage renal failure. Clinically, it has the non-specific characteristics of other slowly-evolving chronic interstitial nephritis (Chapter 86). Perhaps distinctive is an inconsistent history of episodes of dysuria, sometimes loin pain, in earlier disease. Its aetiology remains unsolved. Maps of incidence commonly show a mosaic pattern, suggesting that exposure to local factors are implicated. It has been associated with working outdoors in high temperatures, but this seems inadequate as the sole explanation. Exposure to nephrotoxins, natural or possibly as agrochemicals, seems likely.