LETTERS CHRONIC KIDNEY DISEASE IN CENTRAL AMERICA: THE BIG PICTURE In their November Editorial, Wesseling et al. relay conclusions of the First International Research Workshop on Mesoamerican Nephropathy specifying heat exposure and dehydration as key risk factors or essential cofactors for chronic kidney disease of unknown origin (CKDu).1,2 The Editorial simultaneously downplays substantial research from El Salvador and Sri Lanka, which suggests toxic agrochemicals as key in the disease’s etiology.3,4 The authors also downplay the degree to which industry has sponsored some of the major research carried out to date. The largest study of CKDu in Nicaragua, for example, was organized by the World Bank’s International Finance Corporation (IFC) and funded by a major sugar producer as part of a mediated agreement with complainant workers.5 More recently, the Centers for Disease Control and Prevention has announced three studies into CKDu with funding from the Central American sugar industry, at least one of which is to be led by the same epidemiologist who conducted the IFC study.6 By contrast, governments and
the World Health Organization funded the Salvadoran and Sri Lankan studies. The People’s Health Movement (PHM) contends that the Editorial’s envisaged focus for future research and intervention around lifestyle factors is victim blaming and near-sighted, and will result in overly simplistic public health interventions. We note the alternative approaches and applaud the subsequent interventions enacted based on the precautionary principle in both Sri Lanka and El Salvador. Both countries have banned chemicals of concern, and El Salvador has implemented a primary care based prevention program encompassing all risk factors.7,8 PHM considers the conclusions of the Editorial enabling of an erroneous emergent narrative regarding CKDu that feeds into a corporate political agenda, encourages faulty science, and spawns overly simplistic solutions. To not reveal the whole picture shown by research about CKDu is to betray affected communities around the world. j Lori Hanson, PhD, MSc Leigh K. Haynes, JD, MPH Laura Turiano, MS-PA
About the Authors Letters to the editor referring to a recent Journal article are encouraged up to 3 months after the article's appearance. By submitting a letter to the editor, the author gives permission for its publication in the Journal. Letters should not duplicate material being published or submitted elsewhere. The editors reserve the right to edit and abridge letters and to publish responses. Text is limited to 400 words and 10 references. Submit online at www. editorialmanager.com/ajph for immediate Web posting, or at ajph.edmgr.com for later print publication. Online responses are automatically considered for print publication. Queries should be addressed to the Editor-in-Chief, Mary E. Northridge, PhD, MPH, at [email protected].
Lori Hanson is with the Department of Community Health and Epidemiology, University of Saskatchewan, People’s Health Movement-Canada, Saskatoon. Leigh K. Haynes and Laura Turiano are with the People’s Health MovementUSA, Oakland, CA. Correspondence should be sent to Leigh K. Haynes, JD, MPH, 3355 Guido St. Oakland, CA 94602 (e-mail: leigh. [email protected]). Reprints can be ordered at http://www. ajph.org by clicking the “Reprints” link. This letter was accepted February 28, 2014. doi:10.2105/AJPH.2014.301984
Contributors All authors contributed equally to the research, drafting, and finalization of this letter.
References 1. Wesseling C, Crow J, Hagstedt 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---1930.
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2. Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman D (eds). Mesoamerican Nephropathy: Report From the First International Research Workshop on MeN. Heredia, Costa Rica: Program on Work, Environment and Health in Central America (SALTRA). 2013. Available at: http://www.saltra.una.ac.cr/images/ SALTRA/Documentacion/SerieSaludTrabajo/ seriesaludytrabajo10.pdf. Accessed February 20, 2014. 3. Jayatilake N, Medis S, Maheepala P, Mehta F. Chronic kidney disease of uncertain aetiology: prevalence and causative factors in a developing country. BMC Nephrol. 2013;14:180. 4. Orantes CM, Herrera R, Almaguer M, et al. Chronic kidney disease and associated risk factors in the Bajo Lempa region of El Salvador: Nefrolempa study, 2009. MEDICC Rev. 2011;13(4):14---22. 5. Brooks D, McClean M. Summary Report: Boston University Investigation of Chronic Kidney Disease in Western Nicaragua, 2009-2012. 2012. Available at http://www.cao-ombudsman.org/documents/BU_ SummaryReport_August122012.pdf. Accessed February 20, 2014. 6. Chavkin S. CDC launches industry-financed studies of deadly kidney disease in Central America. In: Mystery in the Fields. The Center for Public Integrity. 2014. Available at: http://www.publicintegrity.org/health/ mystery-fields. Accessed Feb 16, 2014. 7. ColomboPage. Sri Lanka implements measures to prevent kidney disease, bans import of agrochemicals. ColomboPage. April 8, 2013. Available at: http://www. colombopage.com/archive_13A/Apr08_1365421309CH. php. Accessed February 15, 2014. 8. Asamblea Legislativa aprueba reformas que prohíben pesticidas que dañan la salud [Legislative Assembly approves reforms that prohibit pesticides that are harmful to health]. Legislative Assembly of El Salvador. Available at: http://asamblea.gob.sv/noticias/archivo-de-noticias/ asamblea-legislativa-aprueba-reformas-que-prohibenpesticidas-que-danan-la-salud. Accessed February 15, 2013.
WESSELING ET AL. RESPOND We thank Haynes et al. for expressing their concerns on behalf of the People’s Health Movement (PHM) about our recent editorial on the Mesoamerican nephropathy (MeN). We wish to clarify for the readers that PHM is a growing international network of nongovernmental organizations, civil society, and academic organizations who work together toward “ Equity, ecologically sustainable development and peace . . . a world in which a healthy life for all is a reality.”1 We share PHM’s vision. In fact, SALTRA, the organizing entity of the workshop questioned in the Letter to the Editor,
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LETTERS
was recently approached by PHM to join its Fair and Healthy Work campaign circle. This said, we were quite surprised by the fierce accusations: PHM considers the conclusions of the Editorial enabling of an erroneous emergent narrative regarding CKDu [chronic kidney disease of unknown origin] that feeds into a corporate political agenda, encourages faulty science, and spawns overly simplistic solutions . . . is to betray affected communities around the world.
Haynes et al. argue that by communicating the conclusion of the MeN workshop of November 2012 (i.e., that repeated heat stress and dehydration from strenuous working conditions, in particular on sugarcane plantations, is a likely key factor or essential cofactor in the etiology of MeN) we downplayed research that suggest agrochemicals as causal agents and “envisaged focus for future research and intervention around lifestyle factors.” We did not downplay research on the role of pesticides in MeN. We communicated the general opinion constructed during the MeN workshop with more than 50 participants with multiple research disciplines from 15 different countries, who discussed and debated all available data for three days. Although the authors of the Salvadoran study referenced by Haynes et al. hypothesize pesticides as the cause of MeN, the data reported in their article do not support an association between contact with agrochemicals and CKDu (odds ratio = 1.2; 95% confidence interval = 0.7, 2.3).2 The World Health Organization article from Sri Lanka, also referenced by Hayes et al. as supporting pesticides as the cause of CKDu, does show that six pesticides were frequently detected in 56 urine samples of CKDu patients (between 33% and 100% of the samples), but the study did not analyze pesticides in urine of controls, thereby limiting its interpretation.3 However, we agree with Haynes et al. that the pesticide issue merits thorough further exploration, especially as a factor interacting with dehydration. Haynes et al. suggest the pesticide hypothesis is more credible because the results come from government or World Health Organization---funded research, whereas the results pointing to heat stress and dehydration are attributed mostly to World Bank---sponsored research. The conclusions of the workshop4 were based on all studies done in the Mesoamerican region by, among others, SALTRA, 4 different
e10 | Letters
US universities (including the World Bank funded studies), the nongovernment organization La Isla Foundation, the Pan American Health Organization, and the Salvadoran government, most of them conducted with public funding. We agree that industry influence on research is a concern, and note that the sugarcane industry already denies a link between work practices and CKDu in sugarcane workers.5 For effective prevention of this fatal disease we need to act on the strongest scientific evidence available at any given time, which at this time in Mesoamerica we continue to believe is heat stress and repeated dehydration—factors which are system-based and not “lifestyle factors.” Application of the precautionary principle, as Haynes et al. mention in El Salvador and Sri Lanka, is to be supported and applauded for all potential causal factors. Many workers are dying, and every year young workers enter the workforce to be exposed to grueling working conditions on sugarcane plantations, which according to current evidence include added risk of kidney malfunction. These conditions can and should be changed now. We again draw attention to the Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM),6 which was established after the Costa Rican workshop in 2012 and acts as a forum for facilitating debate and research collaboration. There is much work ahead for etiologic and intervention research related to dehydration, pesticides, and a number of other proposed hypotheses. Solutions are urgently needed. Let us collaborate rather than waste energy on unnecessary conflicts. j
Catharina Wesseling, MD, PhD Jennifer Crowe, MSc Christer Hogstedt, MD, PhD Kristina Jakobsson, MD, PhD Rebekah Lucas, PhD David Wegman, MD, MSc
Lund University, Lund, Sweden. Rebekah Lucas is with the Hothaps Program, Umeå International School of Public Health, Umeå University, Umeå, Sweden. David H. Wegman is with Work Environment, University of Massachusetts, Lowell. Correspondence should be sent to Catharina Wesseling, Program on Work, Environment and Health in Central America (SALTRA), Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, PO Box 86-3000, Heredia, Costa Rica (e-mail: [email protected]). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This letter was accepted March 16, 2014. doi:10.2105/AJPH.2014.302029
Contributors The authors form the organizing committee of the 1st International Research Workshop on MeN and are the editors of the corresponding technical workshop report. All authors contributed equally to this letter.
References 1. People’s Health Movement. Available at: http:// www.phmovement.org/en/about. Accessed March 10, 2014. 2. Orantes CM, Herrera R, Almaguer M, et al. Chronic kidney disease and associated risk factors in the Bajo Lempa region of El Salvador: Nefrolempa study, 2009. MEDICC Rev. 2011;13:14---22. 3. Jayatilake N, Medis S, Maheepala P, Mehta F. Chronic kidney disease of uncertain aetiology: prevalence and causative factors in a developing country. BMC Nephrol. 2013;14:180. 4. Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman D (eds). Mesoamerican Nephropathy: Report from the First International Research Workshop on MeN. Heredia, Costa Rica: Program on Work, Environment and Health in Central America (SALTRA); 2013. Available at: http://www.saltra.una.ac.cr/images/ SALTRA/Documentacion/SerieSaludTrabajo/ seriesaludytrabajo10.pdf. Accessed 10 March 2014. 5. Chavkin S. CDC launches industry-financed studies of deadly kidney disease in Central America. The Center for Public Integrity. 2014. Available at: http://www. publicintegrity.org/2014/02/12/14236/cdc-launchesindustry-financed-studies-deadly-kidney-disease-centralamerica. Accessed March 12, 2014. 6. Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM). Available at: http://www.regionalnephropathy.org/?page_id=63. Accessed March 12, 2014.
About the Authors Catharina Wesseling and Jennifer Crowe are with the Program on Work, Environment and Health in Central America (SALTRA), Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica. Christer Hogstedt is with the Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden. Kristina Jakobsson is with the Department of Occupational and Environmental Medicine,
American Journal of Public Health | July 2014, Vol 104, No. 7
the World Health Organization funded the Salvadoran and Sri Lankan studies. The People’s Health Movement (PHM) contends that the Editorial’s envisaged focus for future research and intervention around lifestyle factors is victim blaming and near-sighted, and will result in overly simplistic public health interventions. We note the alternative approaches and applaud the subsequent interventions enacted based on the precautionary principle in both Sri Lanka and El Salvador. Both countries have banned chemicals of concern, and El Salvador has implemented a primary care based prevention program encompassing all risk factors.7,8 PHM considers the conclusions of the Editorial enabling of an erroneous emergent narrative regarding CKDu that feeds into a corporate political agenda, encourages faulty science, and spawns overly simplistic solutions. To not reveal the whole picture shown by research about CKDu is to betray affected communities around the world. j Lori Hanson, PhD, MSc Leigh K. Haynes, JD, MPH Laura Turiano, MS-PA
About the Authors Letters to the editor referring to a recent Journal article are encouraged up to 3 months after the article's appearance. By submitting a letter to the editor, the author gives permission for its publication in the Journal. Letters should not duplicate material being published or submitted elsewhere. The editors reserve the right to edit and abridge letters and to publish responses. Text is limited to 400 words and 10 references. Submit online at www. editorialmanager.com/ajph for immediate Web posting, or at ajph.edmgr.com for later print publication. Online responses are automatically considered for print publication. Queries should be addressed to the Editor-in-Chief, Mary E. Northridge, PhD, MPH, at [email protected].
Lori Hanson is with the Department of Community Health and Epidemiology, University of Saskatchewan, People’s Health Movement-Canada, Saskatoon. Leigh K. Haynes and Laura Turiano are with the People’s Health MovementUSA, Oakland, CA. Correspondence should be sent to Leigh K. Haynes, JD, MPH, 3355 Guido St. Oakland, CA 94602 (e-mail: leigh. [email protected]). Reprints can be ordered at http://www. ajph.org by clicking the “Reprints” link. This letter was accepted February 28, 2014. doi:10.2105/AJPH.2014.301984
Contributors All authors contributed equally to the research, drafting, and finalization of this letter.
References 1. Wesseling C, Crow J, Hagstedt 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---1930.
July 2014, Vol 104, No. 7 | American Journal of Public Health
2. Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman D (eds). Mesoamerican Nephropathy: Report From the First International Research Workshop on MeN. Heredia, Costa Rica: Program on Work, Environment and Health in Central America (SALTRA). 2013. Available at: http://www.saltra.una.ac.cr/images/ SALTRA/Documentacion/SerieSaludTrabajo/ seriesaludytrabajo10.pdf. Accessed February 20, 2014. 3. Jayatilake N, Medis S, Maheepala P, Mehta F. Chronic kidney disease of uncertain aetiology: prevalence and causative factors in a developing country. BMC Nephrol. 2013;14:180. 4. Orantes CM, Herrera R, Almaguer M, et al. Chronic kidney disease and associated risk factors in the Bajo Lempa region of El Salvador: Nefrolempa study, 2009. MEDICC Rev. 2011;13(4):14---22. 5. Brooks D, McClean M. Summary Report: Boston University Investigation of Chronic Kidney Disease in Western Nicaragua, 2009-2012. 2012. Available at http://www.cao-ombudsman.org/documents/BU_ SummaryReport_August122012.pdf. Accessed February 20, 2014. 6. Chavkin S. CDC launches industry-financed studies of deadly kidney disease in Central America. In: Mystery in the Fields. The Center for Public Integrity. 2014. Available at: http://www.publicintegrity.org/health/ mystery-fields. Accessed Feb 16, 2014. 7. ColomboPage. Sri Lanka implements measures to prevent kidney disease, bans import of agrochemicals. ColomboPage. April 8, 2013. Available at: http://www. colombopage.com/archive_13A/Apr08_1365421309CH. php. Accessed February 15, 2014. 8. Asamblea Legislativa aprueba reformas que prohíben pesticidas que dañan la salud [Legislative Assembly approves reforms that prohibit pesticides that are harmful to health]. Legislative Assembly of El Salvador. Available at: http://asamblea.gob.sv/noticias/archivo-de-noticias/ asamblea-legislativa-aprueba-reformas-que-prohibenpesticidas-que-danan-la-salud. Accessed February 15, 2013.
WESSELING ET AL. RESPOND We thank Haynes et al. for expressing their concerns on behalf of the People’s Health Movement (PHM) about our recent editorial on the Mesoamerican nephropathy (MeN). We wish to clarify for the readers that PHM is a growing international network of nongovernmental organizations, civil society, and academic organizations who work together toward “ Equity, ecologically sustainable development and peace . . . a world in which a healthy life for all is a reality.”1 We share PHM’s vision. In fact, SALTRA, the organizing entity of the workshop questioned in the Letter to the Editor,
Letters | e9
LETTERS
was recently approached by PHM to join its Fair and Healthy Work campaign circle. This said, we were quite surprised by the fierce accusations: PHM considers the conclusions of the Editorial enabling of an erroneous emergent narrative regarding CKDu [chronic kidney disease of unknown origin] that feeds into a corporate political agenda, encourages faulty science, and spawns overly simplistic solutions . . . is to betray affected communities around the world.
Haynes et al. argue that by communicating the conclusion of the MeN workshop of November 2012 (i.e., that repeated heat stress and dehydration from strenuous working conditions, in particular on sugarcane plantations, is a likely key factor or essential cofactor in the etiology of MeN) we downplayed research that suggest agrochemicals as causal agents and “envisaged focus for future research and intervention around lifestyle factors.” We did not downplay research on the role of pesticides in MeN. We communicated the general opinion constructed during the MeN workshop with more than 50 participants with multiple research disciplines from 15 different countries, who discussed and debated all available data for three days. Although the authors of the Salvadoran study referenced by Haynes et al. hypothesize pesticides as the cause of MeN, the data reported in their article do not support an association between contact with agrochemicals and CKDu (odds ratio = 1.2; 95% confidence interval = 0.7, 2.3).2 The World Health Organization article from Sri Lanka, also referenced by Hayes et al. as supporting pesticides as the cause of CKDu, does show that six pesticides were frequently detected in 56 urine samples of CKDu patients (between 33% and 100% of the samples), but the study did not analyze pesticides in urine of controls, thereby limiting its interpretation.3 However, we agree with Haynes et al. that the pesticide issue merits thorough further exploration, especially as a factor interacting with dehydration. Haynes et al. suggest the pesticide hypothesis is more credible because the results come from government or World Health Organization---funded research, whereas the results pointing to heat stress and dehydration are attributed mostly to World Bank---sponsored research. The conclusions of the workshop4 were based on all studies done in the Mesoamerican region by, among others, SALTRA, 4 different
e10 | Letters
US universities (including the World Bank funded studies), the nongovernment organization La Isla Foundation, the Pan American Health Organization, and the Salvadoran government, most of them conducted with public funding. We agree that industry influence on research is a concern, and note that the sugarcane industry already denies a link between work practices and CKDu in sugarcane workers.5 For effective prevention of this fatal disease we need to act on the strongest scientific evidence available at any given time, which at this time in Mesoamerica we continue to believe is heat stress and repeated dehydration—factors which are system-based and not “lifestyle factors.” Application of the precautionary principle, as Haynes et al. mention in El Salvador and Sri Lanka, is to be supported and applauded for all potential causal factors. Many workers are dying, and every year young workers enter the workforce to be exposed to grueling working conditions on sugarcane plantations, which according to current evidence include added risk of kidney malfunction. These conditions can and should be changed now. We again draw attention to the Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM),6 which was established after the Costa Rican workshop in 2012 and acts as a forum for facilitating debate and research collaboration. There is much work ahead for etiologic and intervention research related to dehydration, pesticides, and a number of other proposed hypotheses. Solutions are urgently needed. Let us collaborate rather than waste energy on unnecessary conflicts. j
Catharina Wesseling, MD, PhD Jennifer Crowe, MSc Christer Hogstedt, MD, PhD Kristina Jakobsson, MD, PhD Rebekah Lucas, PhD David Wegman, MD, MSc
Lund University, Lund, Sweden. Rebekah Lucas is with the Hothaps Program, Umeå International School of Public Health, Umeå University, Umeå, Sweden. David H. Wegman is with Work Environment, University of Massachusetts, Lowell. Correspondence should be sent to Catharina Wesseling, Program on Work, Environment and Health in Central America (SALTRA), Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, PO Box 86-3000, Heredia, Costa Rica (e-mail: [email protected]). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This letter was accepted March 16, 2014. doi:10.2105/AJPH.2014.302029
Contributors The authors form the organizing committee of the 1st International Research Workshop on MeN and are the editors of the corresponding technical workshop report. All authors contributed equally to this letter.
References 1. People’s Health Movement. Available at: http:// www.phmovement.org/en/about. Accessed March 10, 2014. 2. Orantes CM, Herrera R, Almaguer M, et al. Chronic kidney disease and associated risk factors in the Bajo Lempa region of El Salvador: Nefrolempa study, 2009. MEDICC Rev. 2011;13:14---22. 3. Jayatilake N, Medis S, Maheepala P, Mehta F. Chronic kidney disease of uncertain aetiology: prevalence and causative factors in a developing country. BMC Nephrol. 2013;14:180. 4. Wesseling C, Crowe J, Hogstedt C, Jakobsson K, Lucas R, Wegman D (eds). Mesoamerican Nephropathy: Report from the First International Research Workshop on MeN. Heredia, Costa Rica: Program on Work, Environment and Health in Central America (SALTRA); 2013. Available at: http://www.saltra.una.ac.cr/images/ SALTRA/Documentacion/SerieSaludTrabajo/ seriesaludytrabajo10.pdf. Accessed 10 March 2014. 5. Chavkin S. CDC launches industry-financed studies of deadly kidney disease in Central America. The Center for Public Integrity. 2014. Available at: http://www. publicintegrity.org/2014/02/12/14236/cdc-launchesindustry-financed-studies-deadly-kidney-disease-centralamerica. Accessed March 12, 2014. 6. Consortium on the Epidemic of Nephropathy in Central America and Mexico (CENCAM). Available at: http://www.regionalnephropathy.org/?page_id=63. Accessed March 12, 2014.
About the Authors Catharina Wesseling and Jennifer Crowe are with the Program on Work, Environment and Health in Central America (SALTRA), Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, Heredia, Costa Rica. Christer Hogstedt is with the Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden. Kristina Jakobsson is with the Department of Occupational and Environmental Medicine,
American Journal of Public Health | July 2014, Vol 104, No. 7
