Letter to the Editor

Dear Editor/EHPM

I am pleased to read the major effort and perhaps the best review article to date in the field of chronic kidney disease (CKD) of multi-factorial origin in Sri Lanka in the EHPM journal [1]. In this review, he succinctly and unbiasedly illustrated all the potential contributing factors postulated to date (Figs. 2, 3). These include heavy metals (lead, cadmium, arsenic, mercury, and uranium), aristolochic acid, infectious etiology (leptospirosis, hantavirus, malaria, leprosy, schistosomiasis), exertion/heatstroke, agrochemical and pesticide exposure, etc. [1, 2].

In Sri Lanka, CKD of multi-factorial origin (CKD-mfo; also known as CKD of unknown aetiology; CKDu/CKD-uo) was first described in the mid-1990s, but the cause is unknown [1, 2]. A multi-year research program by the National Research Team in Sri Lanka has failed to identify a single cause for this disease [3], but acknowledges that it is most likely due to multiple agents and supports the terminology of CKD-mfo that has been used by Professor Wimalawansa for many years and presented in an sophisticated, authoritative national oration in 2013 [4].

In his review articles, Professor Wimalawansa also elegantly illustrates that CKD-mfo is likely due to synergistic efforts of several factors and is an “environmentally acquired, occupational disease” [1, 5, 6]. This is also supported by the geographical dissemination of the disease and the locations of hard water in Sri Lanka that have been available since the early 2000 [3, 4].

None of the data available to date, however, support several of the currently dominating hypotheses including the effect of glyphosate, fluoride, heavy metals, aristolochic acid, or ionicity [2–4]. These hypotheses have been presented without validated scientific evidence or experimental data. We appreciate the vast singlehanded contribution of Professor Wimalawansa to the CKD-mfo field [1, 4–6].