Comment: Mesoamerican nephropathy – new evidence and the need to act now David Wegman1, Jason Glaser2, Richard J. Johnson3,4, Christer Hogstedt4, Catharina Wesseling4 1
Department of Work Environment, University of Massachusetts Lowell, Lowell, MA, USA, 2La Isla Foundation, Leo´n, Nicaragua and Chicago, IL, USA, 3Division of Kidney Diseases and Hypertension, University of Colorado, Denver, CO, USA, 4Unit of Occupational Medicine, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
We welcome the publication ‘‘Changes in kidney function among Nicaraguan sugarcane workers,’’1 which raises important issues regarding the Mesoamerican nephropathy (MeN), an epidemic of chronic kidney disease (CKD) of non-traditional etiology (CKDnT) – not explained by known risk factors. This epidemic along the Pacific coast of Mesoamerica has caused the death of many thousands of workers over decades in multiple countries, but only recently has it become known in the international scientific community.2,3 The epidemic has overwhelmed the health systems in affected areas in Central America as it continues to advance. Mesoamerican nephropathy is a public health tragedy of such magnitude and severity that the most urgent, exhaustive, and collaborative actions must be put in place to further elucidate the causes and find solutions for prevention and mitigation. Here, we (a) comment on the study by Laws et al., and (b) how these results were misused by involved financial interests before publication, (c) place the MeN epidemic and its likely causes in global perspective, and (d) present an invitation to participate in the ongoing collaborative efforts to elucidate etiology as well as interventions. During the last 2 years, research in relation to MeN is evolving at an accelerated pace. There are important advances in understanding the multifactorial etiology of the disease with recurrent heat stress and dehydration as suspected key factors.4,5 Despite important progress, data gaps exist and there is no consensus about the complete picture of the epidemic. Regrettably, disagreement about the occupational nature of the disease and about specific
*President of the Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM) Correspondence to: Catharina Wesseling, Karolinksa Institutet, Sweden. Email: [email protected]
ß W. S. Maney & Son Ltd 2015
DOI 10.1179/2049396715Y.0000000008
causes among sugarcane workers – the most affected group of workers – have led to the persistence of deeply troublesome social inequities and even outbreaks of social unrest in the area where the Laws et al. study was carried out.6 In the light of these circumstances, the publication of this first major longitudinal study of CKDnT in sugarcane workers is opportune.1 Besides its cohort design, the study benefits from advances in exposure assessment moving from comparisons of industries to comparisons of job titles. These methodological improvements, as compared to previous population-based prevalence studies, make the results robust. The Laws et al. report documented marked (up to 6 ml/minute/1.73 m2/year) change in eGFR between beginning and end of the harvest, and some studies suggest repeated acute insults on a daily basis. Whether changes are continuous throughout the harvest and whether there is a general recovery during the non-harvest months will be important to determine. The study also provided some suggestive evidence of the importance of water and electrolyte solution intake during the harvest. The authors acknowledge one important limitation of their study population – workers with serum creatinine levels i1.4 mg/dl were not hired at the start of the harvest season. It is unknown how many self-selected from applying for work knowing the company’s hiring policy, but at least 58 were not hired for elevated serum creatinine, and most of these were cane cutters and seed cutters,7 exactly the most affected work groups in this study. Even with such selection operating, the findings indicate that cane cutters had the lowest pre-harvest eGFR values. Laws et al. conclude: ‘‘The observed decline in kidney function during the harvest, as well as the differences in kidney function by job category and employment duration provide evidence that one or
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more risk factors are occupational. These results, as well as the protective effect of consuming electrolyte solution, are consistent with the hypothesis that heat stress and dehydration may play a role in Mesoamerican Nephropathy.’’ These conclusions are broadly in agreement with the general consensus of the First International Workshop on MeN: ‘‘The strongest causal hypothesis for the epidemic is repeated episodes of heat stress and dehydration during heavy work in hot climate. A number of potential co-factors are to be considered....’’8 The Laws et al. study was carried out in the context of a mediation process of the Compliance Advisory Ombudsman (CAO), an arbitration mechanism of the World Bank’s International Finance Corporation (IFC). The CAO is utilized when there are grievances lodged by the public regarding the practices and policies of a recipient of an IFC loan. This CAO process was between CKD affected ex-sugarcane workers and a sugarcane company in Nicaragua. Research was funded by the sugarcane producer and the IFC; the funds were administered by the CAO between 2008 and 2012. Stakeholders in the Central American region and beyond have closely watched this research, due to its potential impact on economic and labor policies. The lesson learned from ongoing studies in Central America along with the Laws et al. report is that the way work is performed in sugarcane agriculture must change. We emphasize the urgency in advancing knowledge and in implementing best practices immediately, even in the face of uncertainty. It took almost 3 years between the first online report and the formal publication of the study by Laws et al. During this time, the company under study continued to deny the occupational link;9,10 the IFC granted another multimillion dollar loan to another sugarcane company in Nicaragua based on the supposedly negative findings of the research carried out under the CAO process;11 and many workers have fallen ill or suffered disease progression and died. Given the study’s published conclusion implicating poor hydration and exposure to heat as primary risk factors, it is evident that work conditions are important. The marked difference between prepublication public pronouncements and the actual published findings emphasizes the danger and significant consequences of companies irresponsibly promoting self-interest under conditions in which their work practices may be suspect. In striking contrast, another representative of the sugarcane industry, Ingenio El Angel in El Salvador, has opened its doors to research for a major intervention study that is evaluating impact on kidney health and heat stress illnesses. This study is using a protocol that broadly follows OSHA’s Water-Shade-Rest
334
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program to prevent heat stress and dehydration among sugarcane cutters, as well as introducing productivity enhancements to reduce workload proven to be effective elsewhere.12 The study is exploring frequent rest breaks under shade tents and access to fresh water for intake ad libitum. Exposure to toxic agricultural chemicals and other environmental agents are also assessed in an effort to enhance understanding of remediable factors so that preventive action can be taken quickly. At the same time, the unraveling of the etiology of the MeN epidemic is ongoing. There is some progress in experimental research to address the biological plausibility and mechanisms of proposed causes.13 Some headway is also being made to characterize the disease in other regions of Mesoamerica and among specific worker populations, as well as in investigating social contexts and realistic treatment and mitigation options. Research to identify genetic patterns and address genetic interactions has started in Nicaragua (D. Brooks, Boston University, personal communication). Finally, research to identify how epidemics of CKDnT in other parts of the world (e.g. Sri Lanka, India, South America)14–17 correspond to the epidemic in Mesoamerica, is getting under way. There is much left to be done but little time for so many current sufferers of CKDnT as well as those continuing at risk of developing CKDnT. Likely, most health practitioners are unaware of how large is the magnitude of CKD burden in both developed and developing nations. A recent Lancet series on CKD notes that the global prevalence of CKD at 10% is approximately the same as the prevalence of diabetes,18 and deaths of CKD have risen in the list of causes of total number of global deaths from 27 in 1990 to 18 in 2010, growing the third fastest when compared with all other causes except for HIV and diabetes.19 The burden of CKD in developing countries is particularly unrecognized.20 When the causes of increased prevalence of CKD are examined, attention is given mostly to conditions related to modern society – diabetes and hypertension – and the increase in CKDnT is largely overlooked in the global CKD summary. Evidence of CKDnT epidemics appears in several developing nations across the globe but none as well documented as MeN. We want to take this opportunity to draw lessons from the studies of CKD and work in hot environments to inform essential safe work practices necessary in all strenuous labor in hot environments, especially in the broader agriculture and construction sectors. Furthermore, these studies have significant implications for the evolution of work in an era of continued climate change.21 Predictably, the problems of work in hot environments are going to
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become even worse in the near future. It is imperative that countries in regions particularly affected by climate change begin now to address the epidemic of CKD more proactively as the costs of treatment greatly exceed the support of research and the regulation of preventive policies and practices. Also, we are optimistic that the studies in Mesoamerica will have application across the globe. Reports from Sri Lanka and India indicate that CKDnT is also a problem in these nations.14–16 There is anecdotal evidence that the problem may even exist in the migrant labor community in Western US [JG – personal communication]. Possibly, we will find CKDnT wherever we look carefully. Will it be exclusively due to inadequate water, rest, and shade or is the problem more complex and due to a combination of unreasonable working conditions along with exposures to some toxic agent(s)? Regardless it is important to look more closely at CKD wherever it occurs to be certain that the etiology is not inappropriately attributed to diabetes or hypertension alone. One final comment – in Mesoamerica, we have been attempting to build research collaborations to address the epidemic. The university-based program on Work and Health in Central America, SALTRA, in Costa Rica, organized three research meetings on this topic, the last resulting in the creation of the Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM) to facilitate research and research collaboration.3 SALTRA and CENCAM are actively planning the Second International Research Workshop in San Jose´, Costa Rica to be held in November 2015. Furthermore, two important political meetings also focused attention on CKDnT in Central America resulting, in April 2013, in the San Salvador Declaration of the Council of Ministers of Health of Central America and the Dominican Republic (COMISCA) that CKD is a significant public health problem in Central America and requires urgent action, and in October 2013, in the PAHO accepted Resolution (CD52/8) urging action in PAHO member states to promote research and form partnerships among all actors to address CKDnT as a ‘‘serious public health problem.’’ Our focus is becoming clearer, our research knowledge is expanding and opportunities to make a difference are becoming evident. There will always be more to learn, and we encourage occupational, environmental and nephrology researchers of all types to become engaged in finding the best answers to this epidemic. But our bottom line is that it is well past time to move from etiologic hypotheses to evidence based solutions. Please join us
Mesoamerican nephropathy
Disclaimer Statements Contributors David Wegman and Catharina Wesseling wrote the first draft of this commentary, which was edited by the remaining members of the group. The final version was approved by all authors. Funding None. Conflicts of interest David Wegman is the Principal Investigator of the WE Program in El Salvador. All other authors state to have no conflict of interest. Ethics approval Not applicable.
References 1 Laws RL, Brooks DR, Amador JJ, Weiner DE, Kaufman JS, Ramı´rez-Rubio O, et al. Changes in kidney function among Nicaraguan sugarcane workers. Int J Occup Environ Health. 2015 Jan 28:2049396714Y0000000102. [Epub ahead of print]. 2 Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman DH. The epidemic of chronic kidney disease of unknown etiology in Mesoamerica: a call for interdisciplinary research and action. Am J Public Health. 2013;103(11):1927–30. 3 Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman DH. First international research workshop on the Mesoamerican nephropathy. Resolving the enigma of the Mesoamerican nephropathy: a research workshop summary. Am J Kidney Dis. 2014;63(3):396–404. 4 Brooks DR, Ramirez-Rubio O, Amador JJ. CKD in Central America: a hot issue. Am J Kidney Dis. 2012;59(4):481–4. 5 Correa-Rotter R, Wesseling C, Johnson RJ. CKD of unknown origin in Central America: the case for a Mesoamerican nephropathy. Am J Kidney Dis. 2014;63(3):506–20. 6 IUF Sugar Workers Network. Nicaragua: one dead, three wounded in chronic kidney disease protests. 2014 (January 21). Available from: http://www.iuf.org/sugarworkers/nica ragua-one-dead-three-wounded-chronic-kidney-disease-protests (accessed 2015 February 7). 7 McClean MA, Amador JJ, Laws R, Kaufman JS, Weiner DE, Sa´nchez-Rodrı´guez JM, et al. Biological sampling report: investigating biomarkers of kidney injury and chronic kidney disease among workers in western Nicaragua. Boston University School of Public Health: Compliance Advisor Ombudman, Available from: http://www.cao-ombudsman.org/documents/ Biological_Sampling_Report_April_2012.pdf (accessed 2015 February 7) 2012. 8 Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman D, editors. Concluding remarks. Mesoamerican nephropathy: report from the First International Research Workshop on MeN. Heredia, CR: SALTRA/IRET-UNA; 2015; p. 227–228. ISBN 978-9968-924-06-1. Available at: http:// www.saltra.una.ac.cr/index.php/sst-vol-10 (accessed 2015 February 1). 9 Business & Human Rights Resource Centre. Grupo Pellas/Nicaragua Sugar Estates Limited re deaths caused by chronic kidney disease among workers at San Antonio sugar mill in Chichigalpa, Nicaragua. Available from: http://business-humanrights.org/ sites/default/files/media/documents/company_responses/grupo-pe llas-nsel-re-chronic-kidney-disease-nicaragua.doc (accessed 2015 February 12) 2013. 10 Chavkin S. CDC launches industry-financed studies of deadly kidney disease in Central America. Grupo Pellas/Nicaragua Sugar Estates Limited re deaths caused by chronic kidney disease among workers at San Antonio sugar mill in Chichigalpa, Nicaragua. Available from: http://www.pub licintegrity.org/2014/02/12/14236/cdc-launches-industry-financedstudies-deadly-kidney-disease-central-america (accessed 2015 February 12). 11 Chavkin S. World Bank approves loan to sugar plantation amid concerns about kidney disease. The Center for Public Integrity; August 28, 2013 Updated: May 19, 2014. Available from: http://www.publicintegrity.org/2013/08/28/13280/world-
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bank-approves-loan-sugar-plantation-amid-concerns-about-kid ney-disease (accessed 2015 February 12). Fiore K. Hope for sugarcane workers who bear CKD burden. Medpage Today Nephrology. 6 February 2015. Available from: http://www.medpagetoday.com/Nephrology/ESRD/ 49899 (accessed 2015 February 12). Johnson RJ, Sa´nchez-Lozada LG. Chronic kidney disease: Mesoamerican nephropathy – new clues to the cause. Nat Rev Nephrol. 2013;9(10):560–1. Chandrajith R, Nanayakkara S, Itai K, Aturaliya TN, Dissanayake CB, Abeysekera T, et al. Chronic kidney diseases of uncertain etiology (CKDue) in Sri Lanka: geographical distribution and environmental implications. Environ Geochem Health. 2011;33(3):267–78. Elledge MF, Redmon JH, Levine KE, Levine KE, Wickremasinghe RJ, Wanigasariya KP, et al. Chronic kidney disease of unknown etiology in Sri Lanka: quest for understanding and global implications. Research Brief. North Carolina: RTI Press; 2014.
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16 Rajapurkar MM, John GT, Kirpalani AL, Abraham G, Agarwal SK, Almeida AF, et al. What do we know about chronic kidney disease in India: first report of the Indian CKD registry. BMC Nephrol. 2012;13:10. 17 Paula Santos U, Zanetta DM, Terr-Filho M, Burdman EA. Burnt sugarcane harvesting is associated with acute renal dysfunction. Kidney Int. 2014 Sep 17. doi: 10.1038/ki.2014.306. [Epub ahead of print]. 18 The Lancet. The global issue of kidney disease. Lancet. 2013;382(9887):101. 19 Jha V, Garcia-Garcia G, Iseki K, Li Z, Naicker S, Plattner B, et al. Chronic kidney disease: global dimension and perspectives. Lancet. 2013;382(9888):260–72. 20 Meguid El Nahas A, Bello AK. Chronic kidney disease: the global challenge. Lancet. 2005;365(9456):331–40. 21 Roelofs C, Wegman D. Workers: the climate canaries. Am J Public Health. 2014;104(10):1799–801.
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Department of Work Environment, University of Massachusetts Lowell, Lowell, MA, USA, 2La Isla Foundation, Leo´n, Nicaragua and Chicago, IL, USA, 3Division of Kidney Diseases and Hypertension, University of Colorado, Denver, CO, USA, 4Unit of Occupational Medicine, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
We welcome the publication ‘‘Changes in kidney function among Nicaraguan sugarcane workers,’’1 which raises important issues regarding the Mesoamerican nephropathy (MeN), an epidemic of chronic kidney disease (CKD) of non-traditional etiology (CKDnT) – not explained by known risk factors. This epidemic along the Pacific coast of Mesoamerica has caused the death of many thousands of workers over decades in multiple countries, but only recently has it become known in the international scientific community.2,3 The epidemic has overwhelmed the health systems in affected areas in Central America as it continues to advance. Mesoamerican nephropathy is a public health tragedy of such magnitude and severity that the most urgent, exhaustive, and collaborative actions must be put in place to further elucidate the causes and find solutions for prevention and mitigation. Here, we (a) comment on the study by Laws et al., and (b) how these results were misused by involved financial interests before publication, (c) place the MeN epidemic and its likely causes in global perspective, and (d) present an invitation to participate in the ongoing collaborative efforts to elucidate etiology as well as interventions. During the last 2 years, research in relation to MeN is evolving at an accelerated pace. There are important advances in understanding the multifactorial etiology of the disease with recurrent heat stress and dehydration as suspected key factors.4,5 Despite important progress, data gaps exist and there is no consensus about the complete picture of the epidemic. Regrettably, disagreement about the occupational nature of the disease and about specific
*President of the Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM) Correspondence to: Catharina Wesseling, Karolinksa Institutet, Sweden. Email: [email protected]
ß W. S. Maney & Son Ltd 2015
DOI 10.1179/2049396715Y.0000000008
causes among sugarcane workers – the most affected group of workers – have led to the persistence of deeply troublesome social inequities and even outbreaks of social unrest in the area where the Laws et al. study was carried out.6 In the light of these circumstances, the publication of this first major longitudinal study of CKDnT in sugarcane workers is opportune.1 Besides its cohort design, the study benefits from advances in exposure assessment moving from comparisons of industries to comparisons of job titles. These methodological improvements, as compared to previous population-based prevalence studies, make the results robust. The Laws et al. report documented marked (up to 6 ml/minute/1.73 m2/year) change in eGFR between beginning and end of the harvest, and some studies suggest repeated acute insults on a daily basis. Whether changes are continuous throughout the harvest and whether there is a general recovery during the non-harvest months will be important to determine. The study also provided some suggestive evidence of the importance of water and electrolyte solution intake during the harvest. The authors acknowledge one important limitation of their study population – workers with serum creatinine levels i1.4 mg/dl were not hired at the start of the harvest season. It is unknown how many self-selected from applying for work knowing the company’s hiring policy, but at least 58 were not hired for elevated serum creatinine, and most of these were cane cutters and seed cutters,7 exactly the most affected work groups in this study. Even with such selection operating, the findings indicate that cane cutters had the lowest pre-harvest eGFR values. Laws et al. conclude: ‘‘The observed decline in kidney function during the harvest, as well as the differences in kidney function by job category and employment duration provide evidence that one or
International Journal of Occupational and Environmental Health
2015
VOL .
21
NO .
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Mesoamerican nephropathy
more risk factors are occupational. These results, as well as the protective effect of consuming electrolyte solution, are consistent with the hypothesis that heat stress and dehydration may play a role in Mesoamerican Nephropathy.’’ These conclusions are broadly in agreement with the general consensus of the First International Workshop on MeN: ‘‘The strongest causal hypothesis for the epidemic is repeated episodes of heat stress and dehydration during heavy work in hot climate. A number of potential co-factors are to be considered....’’8 The Laws et al. study was carried out in the context of a mediation process of the Compliance Advisory Ombudsman (CAO), an arbitration mechanism of the World Bank’s International Finance Corporation (IFC). The CAO is utilized when there are grievances lodged by the public regarding the practices and policies of a recipient of an IFC loan. This CAO process was between CKD affected ex-sugarcane workers and a sugarcane company in Nicaragua. Research was funded by the sugarcane producer and the IFC; the funds were administered by the CAO between 2008 and 2012. Stakeholders in the Central American region and beyond have closely watched this research, due to its potential impact on economic and labor policies. The lesson learned from ongoing studies in Central America along with the Laws et al. report is that the way work is performed in sugarcane agriculture must change. We emphasize the urgency in advancing knowledge and in implementing best practices immediately, even in the face of uncertainty. It took almost 3 years between the first online report and the formal publication of the study by Laws et al. During this time, the company under study continued to deny the occupational link;9,10 the IFC granted another multimillion dollar loan to another sugarcane company in Nicaragua based on the supposedly negative findings of the research carried out under the CAO process;11 and many workers have fallen ill or suffered disease progression and died. Given the study’s published conclusion implicating poor hydration and exposure to heat as primary risk factors, it is evident that work conditions are important. The marked difference between prepublication public pronouncements and the actual published findings emphasizes the danger and significant consequences of companies irresponsibly promoting self-interest under conditions in which their work practices may be suspect. In striking contrast, another representative of the sugarcane industry, Ingenio El Angel in El Salvador, has opened its doors to research for a major intervention study that is evaluating impact on kidney health and heat stress illnesses. This study is using a protocol that broadly follows OSHA’s Water-Shade-Rest
334
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program to prevent heat stress and dehydration among sugarcane cutters, as well as introducing productivity enhancements to reduce workload proven to be effective elsewhere.12 The study is exploring frequent rest breaks under shade tents and access to fresh water for intake ad libitum. Exposure to toxic agricultural chemicals and other environmental agents are also assessed in an effort to enhance understanding of remediable factors so that preventive action can be taken quickly. At the same time, the unraveling of the etiology of the MeN epidemic is ongoing. There is some progress in experimental research to address the biological plausibility and mechanisms of proposed causes.13 Some headway is also being made to characterize the disease in other regions of Mesoamerica and among specific worker populations, as well as in investigating social contexts and realistic treatment and mitigation options. Research to identify genetic patterns and address genetic interactions has started in Nicaragua (D. Brooks, Boston University, personal communication). Finally, research to identify how epidemics of CKDnT in other parts of the world (e.g. Sri Lanka, India, South America)14–17 correspond to the epidemic in Mesoamerica, is getting under way. There is much left to be done but little time for so many current sufferers of CKDnT as well as those continuing at risk of developing CKDnT. Likely, most health practitioners are unaware of how large is the magnitude of CKD burden in both developed and developing nations. A recent Lancet series on CKD notes that the global prevalence of CKD at 10% is approximately the same as the prevalence of diabetes,18 and deaths of CKD have risen in the list of causes of total number of global deaths from 27 in 1990 to 18 in 2010, growing the third fastest when compared with all other causes except for HIV and diabetes.19 The burden of CKD in developing countries is particularly unrecognized.20 When the causes of increased prevalence of CKD are examined, attention is given mostly to conditions related to modern society – diabetes and hypertension – and the increase in CKDnT is largely overlooked in the global CKD summary. Evidence of CKDnT epidemics appears in several developing nations across the globe but none as well documented as MeN. We want to take this opportunity to draw lessons from the studies of CKD and work in hot environments to inform essential safe work practices necessary in all strenuous labor in hot environments, especially in the broader agriculture and construction sectors. Furthermore, these studies have significant implications for the evolution of work in an era of continued climate change.21 Predictably, the problems of work in hot environments are going to
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become even worse in the near future. It is imperative that countries in regions particularly affected by climate change begin now to address the epidemic of CKD more proactively as the costs of treatment greatly exceed the support of research and the regulation of preventive policies and practices. Also, we are optimistic that the studies in Mesoamerica will have application across the globe. Reports from Sri Lanka and India indicate that CKDnT is also a problem in these nations.14–16 There is anecdotal evidence that the problem may even exist in the migrant labor community in Western US [JG – personal communication]. Possibly, we will find CKDnT wherever we look carefully. Will it be exclusively due to inadequate water, rest, and shade or is the problem more complex and due to a combination of unreasonable working conditions along with exposures to some toxic agent(s)? Regardless it is important to look more closely at CKD wherever it occurs to be certain that the etiology is not inappropriately attributed to diabetes or hypertension alone. One final comment – in Mesoamerica, we have been attempting to build research collaborations to address the epidemic. The university-based program on Work and Health in Central America, SALTRA, in Costa Rica, organized three research meetings on this topic, the last resulting in the creation of the Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM) to facilitate research and research collaboration.3 SALTRA and CENCAM are actively planning the Second International Research Workshop in San Jose´, Costa Rica to be held in November 2015. Furthermore, two important political meetings also focused attention on CKDnT in Central America resulting, in April 2013, in the San Salvador Declaration of the Council of Ministers of Health of Central America and the Dominican Republic (COMISCA) that CKD is a significant public health problem in Central America and requires urgent action, and in October 2013, in the PAHO accepted Resolution (CD52/8) urging action in PAHO member states to promote research and form partnerships among all actors to address CKDnT as a ‘‘serious public health problem.’’ Our focus is becoming clearer, our research knowledge is expanding and opportunities to make a difference are becoming evident. There will always be more to learn, and we encourage occupational, environmental and nephrology researchers of all types to become engaged in finding the best answers to this epidemic. But our bottom line is that it is well past time to move from etiologic hypotheses to evidence based solutions. Please join us
Mesoamerican nephropathy
Disclaimer Statements Contributors David Wegman and Catharina Wesseling wrote the first draft of this commentary, which was edited by the remaining members of the group. The final version was approved by all authors. Funding None. Conflicts of interest David Wegman is the Principal Investigator of the WE Program in El Salvador. All other authors state to have no conflict of interest. Ethics approval Not applicable.
References 1 Laws RL, Brooks DR, Amador JJ, Weiner DE, Kaufman JS, Ramı´rez-Rubio O, et al. Changes in kidney function among Nicaraguan sugarcane workers. Int J Occup Environ Health. 2015 Jan 28:2049396714Y0000000102. [Epub ahead of print]. 2 Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman DH. The epidemic of chronic kidney disease of unknown etiology in Mesoamerica: a call for interdisciplinary research and action. Am J Public Health. 2013;103(11):1927–30. 3 Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman DH. First international research workshop on the Mesoamerican nephropathy. Resolving the enigma of the Mesoamerican nephropathy: a research workshop summary. Am J Kidney Dis. 2014;63(3):396–404. 4 Brooks DR, Ramirez-Rubio O, Amador JJ. CKD in Central America: a hot issue. Am J Kidney Dis. 2012;59(4):481–4. 5 Correa-Rotter R, Wesseling C, Johnson RJ. CKD of unknown origin in Central America: the case for a Mesoamerican nephropathy. Am J Kidney Dis. 2014;63(3):506–20. 6 IUF Sugar Workers Network. Nicaragua: one dead, three wounded in chronic kidney disease protests. 2014 (January 21). Available from: http://www.iuf.org/sugarworkers/nica ragua-one-dead-three-wounded-chronic-kidney-disease-protests (accessed 2015 February 7). 7 McClean MA, Amador JJ, Laws R, Kaufman JS, Weiner DE, Sa´nchez-Rodrı´guez JM, et al. Biological sampling report: investigating biomarkers of kidney injury and chronic kidney disease among workers in western Nicaragua. Boston University School of Public Health: Compliance Advisor Ombudman, Available from: http://www.cao-ombudsman.org/documents/ Biological_Sampling_Report_April_2012.pdf (accessed 2015 February 7) 2012. 8 Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman D, editors. Concluding remarks. Mesoamerican nephropathy: report from the First International Research Workshop on MeN. Heredia, CR: SALTRA/IRET-UNA; 2015; p. 227–228. ISBN 978-9968-924-06-1. Available at: http:// www.saltra.una.ac.cr/index.php/sst-vol-10 (accessed 2015 February 1). 9 Business & Human Rights Resource Centre. Grupo Pellas/Nicaragua Sugar Estates Limited re deaths caused by chronic kidney disease among workers at San Antonio sugar mill in Chichigalpa, Nicaragua. Available from: http://business-humanrights.org/ sites/default/files/media/documents/company_responses/grupo-pe llas-nsel-re-chronic-kidney-disease-nicaragua.doc (accessed 2015 February 12) 2013. 10 Chavkin S. CDC launches industry-financed studies of deadly kidney disease in Central America. Grupo Pellas/Nicaragua Sugar Estates Limited re deaths caused by chronic kidney disease among workers at San Antonio sugar mill in Chichigalpa, Nicaragua. Available from: http://www.pub licintegrity.org/2014/02/12/14236/cdc-launches-industry-financedstudies-deadly-kidney-disease-central-america (accessed 2015 February 12). 11 Chavkin S. World Bank approves loan to sugar plantation amid concerns about kidney disease. The Center for Public Integrity; August 28, 2013 Updated: May 19, 2014. Available from: http://www.publicintegrity.org/2013/08/28/13280/world-
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bank-approves-loan-sugar-plantation-amid-concerns-about-kid ney-disease (accessed 2015 February 12). Fiore K. Hope for sugarcane workers who bear CKD burden. Medpage Today Nephrology. 6 February 2015. Available from: http://www.medpagetoday.com/Nephrology/ESRD/ 49899 (accessed 2015 February 12). Johnson RJ, Sa´nchez-Lozada LG. Chronic kidney disease: Mesoamerican nephropathy – new clues to the cause. Nat Rev Nephrol. 2013;9(10):560–1. Chandrajith R, Nanayakkara S, Itai K, Aturaliya TN, Dissanayake CB, Abeysekera T, et al. Chronic kidney diseases of uncertain etiology (CKDue) in Sri Lanka: geographical distribution and environmental implications. Environ Geochem Health. 2011;33(3):267–78. Elledge MF, Redmon JH, Levine KE, Levine KE, Wickremasinghe RJ, Wanigasariya KP, et al. Chronic kidney disease of unknown etiology in Sri Lanka: quest for understanding and global implications. Research Brief. North Carolina: RTI Press; 2014.
International Journal of Occupational and Environmental Health
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