Abstract

Chronic Kidney Disease of undetermined cause (CKDu) is affecting agricultural communities in Central America, South Asia, and possible other parts of the world. Various possible causes have been suggested, including heat/dehydration, pesticides, infections, and water contamination/heavy metals. In particular, it has been suggested that CKDu is an occupational disease caused by various working conditions (heat stress, pesticides), and that there is a global epidemic. The debate has become increasingly polarised, since most of the various protagonists are arguing in a data-deficient vacuum. We still don’t know, at least on a global level, who gets this disease, or if the disease is the same in different parts of the world. However, evidence is beginning to emerge, based on studies that we are conducting in Nicaragua, Peru, Malawi, India, and Sri Lanka. These new findings indicate that: (i) the disease does not exist globally, but appears at this stage to be confined to Central America and South Asia (India, Sri Lanka) – there are other regions of the world which are also hot and use large amounts of pesticides where the disease does not occur; (ii) it is more common in agricultural areas, but is not confined to sugar cane workers, and also occurs in women, albeit at a lower rate; (iii) there is a very clear distinction between community members who experience marked declines in kidney function and those who do not. Taken together, this emerging evidence indicates that CKDu may be an environmental rather than an occupational disease, and that the environmental cause(s) are unknown at this time. This has important implications in terms of what research we do next to try and find the cause(s) of this condition.