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‘Should we consider renaming ‘Mesoamerican Nephropathy’ as Nephropathy of Unknown Cause in Agricultural Labourers (NUCAL)?’
  1. Srinivas Subramanian1,
  2. Muhammad Masoom Javaid2
  1. 1Department of Medicine, Division of Nephrology, National University Hospital, Singapore, Singapore
  2. 2National University Hospital, Singapore, Singapore
  1. Correspondence to Dr Srinivas Subramanian, American Board Certified in Internal Medicine and Nephrology, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074, Singapore; srinivas_subrama{at}

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Mesoamerican nephropathy (MAN) refers to a kidney disease that primarily afflicts male labourers (usually in the agricultural sector) and has been mainly identified in regions of Central America.1 While the global prevalence and incidence is not known, in the regions where the condition has been recognised, the prevalence has been noted to be between 10% and 15%. Nearly 20 000 deaths have been attributed to this condition from El Salvador alone.2 The aetiology is unclear. It is thought to be contributed to by dehydration, malnutrition, fructose ingestion, electrolyte imbalance, pesticides, environmental toxins and heat injury. The role of genetics or other patient factors is unclear. Clusters of kidney disease with similar presentation have been identified in agricultural labourers in India, Egypt and Sri Lanka. The histopathology of this condition is characterised by interstitial fibrosis and tubular atrophy with glomerulosclerosis similar to that from Central America.3 The term MAN does not reflect the fact that this condition likely occurs beyond the confines of Central America.

The term chronic kidney disease of unknown aetiology is very broad and includes kidney disease due to diverse aetiologies such as chronic glomerulonephritis, a kidney disease from a recognised condition that was not correctly diagnosed in the patient and so on. A better term may be Nephropathy of Unknown Cause in Agricultural Labourers (NUCAL). Even this term may be suboptimal as this does not say much about the pathogenesis of the condition. Once the aetiology of the condition is elucidated appropriate renaming may take place.

Appropriate nomenclature is essential to the patients and science. By labelling this condition as NUCAL, the nephrology community will be recognising this as an occupational hazard for labourers in the agricultural sector. Second, it will be possible to track the cases from parts of the world outside of Central America to help understand the prevalence and incidence of this important condition. Third, by putting these cases from different continents in one basket, it will be possible to study if similar factors are in play in the aetiology and pathogenesis of this condition or if distinct factors play a role in different regions of the world and in different populations.

Much needs to be done to serve these economically disadvantaged and vulnerable populations working in this vital economic sector. History has taught us that when we have an ‘occupational health’ approach to a medical condition, it raises the awareness of the disease, and leads to better protection of the workers in the form of preventive measures and appropriate compensation to those who are affected. The recognition of ‘Coal Workers Pneumoconiosis’ or ‘Black Lung’ is one example.4

There may be various barriers to recognition, treatment, registration of cases and conduct of research such as economics, politics and lack of political will, lack of awareness and education, action from special interest groups and different causes competing for limited resources. We need to act in a timely and effective manner to surmount these barriers. Appropriate nomenclature will help in fostering global awareness and international action.



  • Contributors MMJ was involved in discussion and preparation of the manuscript. His inputs have been incorporated in the manuscript.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; internally peer reviewed.

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