ABSTRACT Introduction: Urolithiasis causes pain, renal functional deterioration and notorious economic expenses. Objectives: To identify the clinical-epidemiological characteristics of nephrolithiasis. Methods: A descriptive, cross-sectional study was conducted in a total of 2,923 people from to three clinics of Plaza de la Revolution Teaching Community Clinic, Plaza de la Revolution municipality, Havana province, Cuba. They were selected by simple random sampling from the 16 clinics that the health area has. The data was obtained through a survey and structured interview. The information was processed automatically (IBMSPSS 22.0). Frequency distribution analysis was used, prevalence rates were calculated and the homogeneity test was used. Results: The prevalence of urolithiasis was 4.99 per 100 inhabitants, 6.3 among men and 5.7 among white-skinned men. The average age at diagnosis was 39.3 years. Among the risk factors for lithiasis, the high intake of oxalates prevailed (97.3%). Ultrasound was the most used form of diagnosis (67.8%). Phytotherapy was the most used medical treatment (69.2%). A medical permit was issued to 16.4% of the patients in the last two years. Conclusions: The prevalence of urinary lithiasis in Plaza de la Revolution Teaching Community Clinic is high, prevailing in males, in white-skinned and middle aged subjects. High oxalate intake is the most common risk factor for urinary lithiasis found. The most used form of diagnosis is ultrasound and the most used treatment is phytotherapy.

RESUMEN Introducción: Las urolitiasis ocasionan dolor, deterioro funcional renal y notorias erogaciones económicas. Objetivos: Identificar las características clínico-epidemiológicas de la nefrolitiasis. Métodos: Estudio descriptivo, transversal. Se estudiaron 2 923 personas pertenecientes a tres consultorios del Policlínico Plaza; municipio Plaza de la Revolución, provincia La Habana, Cuba., seleccionados por muestreo simple aleatorio de los 16 con que cuenta el área de salud. Los datos se obtuvieron mediante encuesta y entrevista estructurada. La información fue procesada de forma automatizada (IBMSPSS 22.0). Se utilizó análisis de distribución de frecuencias, se calcularon tasas de prevalencia, y fue empleado el test de homogeneidad. Resultados: La prevalencia de urolitiasis fue de 4,99 por cada 100 habitantes, de 6,3 entre los varones y de 5,7 en los de piel blanca. La edad promedio al diagnóstico fue de 39,3 años. Entre los factores de riesgo de litiasis predominó la alta ingestión de oxalatos (97,3 %). La ecografía fue la forma de diagnóstico más usada (67,8 %). La fitoterapia fue el tratamiento médico más utilizado (69,2 %). Al 16,4 % de los pacientes se les expidió certificado médico en los últimos dos años. Conclusiones: La prevalencia de litiasis urinaria en el Policlínico Docente “Plaza de la Revolución” es elevada, con predominio en el sexo masculino, en sujetos de piel blanca y en las edades medias de la vida. La alta ingestión de oxalato es el factor de riesgo de litiasis urinaria más frecuente encontrado. La forma de diagnóstico más utilizada es la ecografía y el tratamiento más empleado es la fitoterapia.

ABSTRACT Introduction: Chronic kidney disease mainly affecting male farmers and not associated to traditional causes has been present in Central America for twenty years. The condition is characterized by the presence of chronic interstitial nephritis, but its ultrastructural features are not fully known. Factors suggested as responsible for its occurrence include the use of agrochemicals and other nephrotoxic agents, chronic dehydration and medicine consumption. Objective: Describe the ultrastructural characteristics of chronic interstitial nephritis in farming communities. Method: A cross-sectional descriptive study was conducted of renal biopsy samples from eight patients diagnosed with chronic interstitial nephritis in farming communities. Results: Of the eight patients studied, two (25%) were farm workers and five (62.5%) were female. Two of the patients (25%) had stage 2 and six (75%) stage 3 chronic kidney disease. In five patients evidence was found of phagolysosomes with lipid component mixed with electrodense material in distal tubule cells. An equal number of patients had myeloid bodies with laminated areas and central nucleus in proximal tubule and blood vessel cells. Conclusions: Evidence of phagolysosomes and myeloid structures of unknown content and origin was found in renal tubules and vessels of patients from farming communities diagnosed with chronic interstitial nephritis.

RESUMEN Introducción: Desde hace 20 años se presenta en Centroamérica una enfermedad renal crónica que fundamentalmente afecta a hombres agricultores y no asociada a las causas tradicionales. Se caracteriza por presentar una nefritis intersticial crónica, en tanto las características ultraestructurales no se conocen con exactitud. En su origen se invoca el uso de agroquímicos y otros agentes nefrotóxicos, la deshidratación crónica, el consumo de medicamentos, entre otros factores. Objetivo: Describir las características ultraestructurales de la nefritis intersticial crónica en comunidades agrícolas. Método: Se realizó un estudio descriptivo de corte transversal. Se estudiaron muestras de biopsias renales de ocho pacientes con diagnóstico de nefritis intersticial crónica de las comunidades agrícolas. Resultados: De los ocho pacientes estudiados, dos (25 %) trabajaban en labores agrícolas y cinco eran del sexo femenino (62,5 %). Dos de los pacientes (25 %) presentaban una enfermedad renal crónica estadio 2, y seis (75 %) estadio 3. En cinco pacientes se hallaron fagolisosomas con presencia de componente lipídico entremezclado con material electrodenso en células del túbulo distal. En igual cantidad de pacientes se observaron cuerpos mieloides con zonas laminadas y núcleo central en células de túbulo proximal y de los vasos sanguíneos. Conclusiones: En pacientes de comunidades agrícolas que padecen nefritis intersticial crónica se evidencian fagolisosomas y estructuras mieloides en túbulos y vasos renales, cuyo contenido y origen se desconocen.

ABSTRACT Introduction: An epidemic of chronic kidney disease (CKD) of devastating consequences has been taking place in El Salvador over the last few decades. In a significant portion of affected subjects, no other common cause of chronic kidney disease is present, such as diabetes and hypertension. This illness is usually called Chronic Kidney Disease from Non-Traditional Causes (CKDnT). Previous studies have shown a high prevalence of exposure to agrochemicals in affected populations, particularly in rural areas. In addition to sustained exposure to agrochemicals, the other leading hypothesis to explain this epidemic is prolonged exposure to high temperatures and dehydration in a context of exhausting agricultural work. Objectives: To assess the possible causal effect of exposure to agrochemicals in the emergence of the CKD epidemic in the adult population of El Salvador. Methods: We conducted a case-control analysis based on the 2015 survey of Chronic Diseases in Adults in El Salvador, a national probabilistic sample that covered 4,817 adults ≥20 years old. Those suffering from CKD were considered cases; the rest were managed as controls. Self-reported agrochemical exposures, other risk factors and health conditions were recorded. For binary exposures, the odds ratio (OR) of CKD and CKDnT was estimated. For variables measuring length of exposure, the average values for cases and for controls were compared. In all cases, the corresponding 95% confidence intervals were calculated. Multivariate logistic regression was used to examine the association between exposure to agrochemicals and CKD while controlling for potential confounding variables. Results: Regardless of how past exposure to agrochemicals was characterized (e.g., contact with paraquat or aerial fumigation) the OR of both CKD and CKDnT was always greater than 1.0 (range, 1.36 to 3.75). Similarly, the average number of years of exposure was consistently higher for cases than for controls for all continuous variables examined (greater than 2 years in most cases). Conclusions: The results of this study are consistent with previous epidemiologic and toxicological evidence and support the hypothesis that exposure to agrochemicals may be causally implicated in the ongoing CKD epidemics in El Salvador.

RESUMEN Introducción: Durante las últimas décadas, una epidemia de enfermedad renal crónica (ERC) de consecuencias devastadoras ha tenido lugar en El Salvador. Una parte importante de los sujetos afectados, no padece de una causa frecuente para padecer enfermedad renal crónica, tal como como diabetes e hipertensión. En tal caso, suele distinguirse la dolencia mediante el nombre de Enfermedad Renal Crónica de Causas no Tradicionales (ERCnT). Estudios previos muestran una alta prevalencia de exposición a agroquímicos en las poblaciones afectadas, particularmente en las zonas rurales. Además de la exposición sostenida a agroquímicos, la otra hipótesis principal para explicar esta epidemia es la exposición prolongada a altas temperaturas y deshidratación, en un contexto de trabajo agrícola agotador. Objetivos: Evaluar el posible efecto causal de la exposición a agroquímicos en la irrupción de la epidemia de ERC en la población adulta de El Salvador. Métodos: Se realizó un estudio de casos y controles, a partir de la Encuesta de Enfermedades Crónicas no Transmisibles en Adultos en El Salvador, basada en una muestra probabilística nacional que abarcó 4,817 adultos de 20 o más años de edad, concluida en 2015. Fueron considerados “casos” todos aquellos que padecían ERC; el resto dos restantes participantes se manejaron como controles. Se registraron las exposiciones a agroquímicos, así como a otros factores de riesgo y condiciones de salud según testimonio de los participantes. Para las exposiciones binarias, se estimó la razón de odds (OR) con respecto a padecer ERC y ERCnT. Para las variables que medían la duración de la exposición, se compararon los valores medios para casos y controles. En todos los casos, se calcularon los respectivos intervalos de confianza al 95%. Se utilizó la regresión logística multivariada para examinar la asociación entre la exposición a agroquímicos y la ERC, controlando las posibles variables confusoras. Resultados: Independientemente de cómo fuera caracterizada la exposición pasada a agroquímicos (por ejemplo, contacto con paraquat o fumigación aérea), el OR de ERC y ERCnT siempre fue mayor que 1.0 (rango, 1.36 a 3.75). Del mismo modo, la media de años de exposición fue consistentemente más alta para los casos que para los controles, para todas las variables continuas examinadas (más de 2 años en la mayoría de los casos). Conclusiones: Los resultados de este estudio son consistentes con la evidencia epidemiológica y toxicológica previa y respaldan la hipótesis de que la exposición a agroquímicos puede estar causalmente implicada en la epidemia de ERC que se registra en El Salvador.

In El Salvador, chronic kidney disease had reached epidemic proportions towards the end of this century’s first decade. In 2011–2012, the Ministry of Health reported it was the leading cause of hospital deaths in men, the fifth in women, and the third overall in adult hospital fatalities. Farming was the most common occupation among men in dialysis (50.7%). By 2017, chronic kidney disease admissions had overwhelmed hospital capacity. In 2009, El Salvador’s Ministry of Health, Cuba’s Ministry of Public Health and PAHO launched a cooperative effort to comprehensively tackle the epidemic. The joint investigations revealed a total prevalence of chronic kidney disease in the adult population of farming communities higher than that reported internationally (18% vs.11%–14.8%), higher in men than in women (23.9% vs 13.9%) and higher in men who were farmers/farmworkers than in men who were not (31.3% vs. 14.8%). The disease was also detected in children. An association was found between chronic kidney disease and exposure to agrochemicals (OR 1.4–2.5). In 51.9% of all chronic kidney disease cases, traditional causes (diabetes, hypertension, glomerulopathies, obstructive nephropathies and cystic diseases) were ruled out and the existence of a particular form of chronic kidney disease of nontraditional etiology was confirmed (whose initial cases were reported as early as 2002). In the patients studied, functional alterations and histopathologic diagnosis confirmed a chronic tubulointerstitial nephritis; most presented with neurosensory hearing loss, altered tendon reflexes and tibial artery damage. The main results of this cooperation were the epidemiologic, physiopathologic, clinical and histopathologic characterization of chronic kidney disease of nontraditional etiology. This characterization facilitated case definition for the epidemic and led to the hypothesis of systemic toxicity from agrochemicals (e.g., paraquat, glyphosate), which particularly affect the kidneys and to which farmers/farmworkers (who may also become dehydrated in the fields) are most exposed. The research thus also laid the foundations for design of comprehensive intersectoral government actions to reduce cases and put an end to the epidemic. Chronic kidney disease; chronic renal failure; tubulointerstitial nephritis; epidemiology; histopathology; international cooperation; agrochemicals; environmental pollutants, noxae, and pesticides; occupational health; PAHO; El Salvador; Cuba

ABSTRACT INTRODUCTION Chronic kidney disease has reached epidemic levels in several Central American countries since the early years of this century. In El Salvador, it is the second cause of death in men, the fifth in persons over 18 years old and the third cause of hospital deaths in the adult population. Its features, especially those of a subtype unassociated with traditional risk factors such as diabetes and high blood pressure, are only partially understood. OBJECTIVE Estimate the magnitude of chronic kidney disease in the adult population of El Salvador, considering both prevalence of the disease in its diverse forms as well as presence of potential risk factors nationally and in major subpopulations. METHODS A descriptive, cross-sectional analysis was conducted on data obtained from the Survey of Chronic Non-communicable Diseases in Adults in El Salvador, completed in 2015. The original data (interviews and measurements) were collected between October 2014 and March 2015 from 4817 adults employing a two-stage probabilistic cluster sample, with stratification of primary sampling units. Our analysis, using 20 of the 118 primary variables included in the original survey, focused on point estimation of prevalence rates and means, related to both traditional biological risk factors and nontraditional ones, such as insufficient hydration, strenuous working conditions and exposure to toxic agents. A separate analysis was performed to estimate prevalence of chronic kidney disease from nontraditional causes. Corresponding confidence intervals were calculated with proper weighting. RESULTS The general prevalence of chronic kidney disease in El Salvador was 12.8% (men 18.0%; women 8.7%). Of the chronically ill kidney patients, 13.1% were between 20 and 40 years of age. Among biological risk factors, the most frequent was high blood pressure (37.0%). Among nontraditional risk factors, high levels of sugary drink consumption (81.0%), insufficient hydration (65.9%) and high levels of exposure to agrochemicals in the work environment (12.6%) were also observed. Prevalence of chronic kidney disease from nontraditional causes was 3.9% (men 6.1%; women 2.2%). CONCLUSIONS Chronic kidney disease has reached epidemic proportions in El Salvador. The data confirm a health tragedy that, although especially striking older men, also takes a severe toll on young men and women. The results confirm findings of previous research in several Salvadoran agricultural communities. The relatively high level of population exposure to agrochemicals is important and alarming, especially in rural areas, meriting health-impact studies that include and go beyond possible impact on chronic kidney disease.

ABSTRACT Introduction: The basis of the National Health System in Cuba is the Primary Health Care; the family doctor registers the patients to evaluate the risks, to carry out the treatment, and follow-up them in the community. Chronic Kidney Disease affects the 10% of the adult population, that is why the active surveillance is necessary. Objectives: To evaluate and compare all patient registries of Chronic Kidney Disease and Chronic Kidney Disease with Diabetes Mellitus (2014- 2017). Material and Methods: The total of patients registered with Chronic Kidney Disease (glomerular filtration rate <60 mL/min/1.73 m2), and among them the diabetic patients; comparing the prevalence rate per 1 000 inhabitants, (sex, age, province). The data were obtained from the registries of the National Direction for Statistics. Results: Dispensarization increased in 2017 vs 2014: CKD 21,0%, and CKD with diabetes mellitus 47,21%. It increased according to age and it reached its maximum value in the group of 60-64 year-old ages for the CKD (8,99 per 1 000 inhabitants) and among them, more than 65 years old (1,35 per 1 000 inhabitants) for CKD with Diabetes Mellitus. There are differences in rates in the provinces in a frequency of CKD (6,28-1,06), and CKD with Diabetes Mellitus (0,82-0,11). The diagnosis of CKD-DM vs the existent diabetic and dispensarized population between 1,25-0,1% also varies. Conclusions: The dispensarization has increased for CKD and CKD with Diabetes Mellitus. The cuban state guarantees the sustainability of the universal access of the medical care in each community; the advice to patients; the diagnostic tools and the covering of essential medications.

RESUMEN Introducción: La base del Sistema Nacional de Salud en Cuba es el médico de la familia quienes registran, evalúan los riesgos, tratan y siguen a los pacientes en su comunidad. La enfermedad renal crónica afecta al 10% de la población adulta por lo cual es necesaria su activa vigilancia. Objetivos: evaluar y comparar la dispensarización por ERC y ERC-DM entre 2014 y 2017. Material y Métodos: Pacientes registrados con ERC (tasa de filtración glomerular <60 mL/min/1,73 m2) total y de causa diabética; tasa de prevalencia x 1 000 habitantes, (sexo, edad, provincia). Los datos se obtuvieron de los registros de la Dirección Nacional de Estadísticas. Resultados: Se incrementa la dispensarizacion en 2017 vs 2014: por ERC 21%, y de ellos con ERC ocasionada por diabetes en un 47,21%. Existió un aumento a mayor edad y alcanzó su valor máximo en el grupo de edades de 60-64 años para la ERC (8,99 x 1 000 habitantes) y entre los mayores de 65 años (1,35 x 1 000 habitantes) para la ERC-DM. Existen diferencias en las tasas provinciales, en la frecuencia de ERC (6,28-1,06), y de ERC-DM (0,82-0,11), también varía el diagnostico ERC-DM vs la población diabética existente y dispensarizada entre un 1,25-0,1% Conclusiones: Existe una mejoría en la dispensarización por ERC y por ERC-DM. La garantía por el Estado Cubano del acceso universal, de la atención centrada desde cada comunidad; en el asesoramiento a los pacientes; de las herramientas diagnósticas y la cobertura de medicamentos esenciales garantiza su sostenibilidad.

ABSTRACT Non-communicable diseases (NCDs) represent one of the greatest challenges for development of the 21st century due to their devastating social, economic and public health impact. The objective of this article are to describe the evolution and risk factors for NCDs in Cuba, mainly in the period 1990–2015, to outline actions undertaken by the Ministry of Public Health of Cuba, and to highlight the most important challenges with a focus on their prevention and control. The information is based on data collected and published by the Directorate of Medical Records and Health Statistics, research on risk factors, other studies and documentation of comprehensive actions. Mortality in Cuba is determined by four major health problems: cardiovascular diseases, malignant tumors, chronic diseases of the lower respiratory tract and diabetes mellitus, which together cause 68.0% of deaths. Cancer presents a growing trend, and chronic kidney disease emerges as a serious health problem. Cuba has a known baseline on risk factors, and hypertension and tobacco consumption are the main factors related to NCDs mortality. In line with the importance of these diseases, there are milestones and interventions with a positive impact, as well as gaps and challenges within the framework of the World Health Organization’s Global Action Plan for the Prevention and Control of NCDs.

RESUMEN Las enfermedades no transmisibles (ENT) representan uno de los mayores desafíos para el desarrollo en el siglo XXI, debido al devastador impacto social, económico y de la salud pública que provocan. El propósito de este artículo es describir la evolución y los factores de riesgo de las ENT en Cuba, principalmente en el período 1990–2015, reseñar las acciones emprendidas por el Ministerio de Salud Pública y destacar los desafíos más importantes para su prevención y control. La información contenida proviene de los datos colectados y publicados por la Dirección de Registros Médicos y Estadísticas de Salud, investigaciones sobre los factores de riesgo, otros estudios fundamentados y la documentación de acciones integrales. La mortalidad en Cuba está determinada por cuatro grandes problemas de salud: enfermedades cardiovasculares, tumores malignos, enfermedades crónicas de las vías respiratorias inferiores y diabetes mellitus, que en conjunto causan el 68,0% de los fallecimientos. La tendencia del cáncer es al ascenso y la enfermedad renal crónica emerge como un grave problema de salud. Cuba cuenta con una línea de base conocida sobre los factores de riesgo, de ellos la hipertensión y el consumo de tabaco son los principales relacionados con la mortalidad por ENT. En consonancia con la importancia de estas enfermedades se aprecian hitos e intervenciones de impacto positivo, así como brechas y desafíos en el marco del Plan de Acción Mundial de la Organización Mundial de la Salud para el enfrentamiento a las ENT.

RESUMO As doenças não transmissíveis (DNT) representam um dos maiores desafios do século 21 para o desenvolvimento devido ao desvastador impacto social, econômico e de saúde pública que elas causam. O objetivo deste artigo é descrever a evolução e os fatores de risco das doenças não transmissíveis em Cuba, principalmente no período de 1990–2015, para delinear as ações realizadas pelo Ministério da Saúde Pública de Cuba e destacar os desafios mais importantes para sua prevenção e controle. A informação vem dos dados coletados e publicados pela Diretoria de Registros Médicos e Estatísticas de Saúde, pesquisa sobre fatores de risco, outros estudos fundamentados e documentação de ações abrangentes. A mortalidade em Cuba é determinada por quatro principais problemas de saúde: doenças cardiovasculares, tumores malignos, doenças crônicas do trato respiratório inferior e diabetes mellitus, que em conjunto causam 68,0% das mortes. O câncer tem uma tendência crescente, e a doença renal crônica surge como um grave problema de saúde. Cuba tem uma linha de base conhecida sobre os fatores de risco, dos quais a hipertensão e o consumo de tabaco são os principais relacionados à mortalidade por DNT. Em consonância com a importância dessas doenças, há marcos e intervenções com impacto positivo, bem como lacunas e desafios no âmbito do Plano de Ação Mundial da Organização Mundial da Saúde para enfrentar as doenças não transmissíveis.

Abstract Corn is the main source of food and the largest crop cultivated in Mexico. In the state of Guerrero there is great diversity of agro-ecological regions distinguished by its altitude, temperature, soil type, rainfall distribution, where farmers grow hybrid varieties and native population’s of corn under irrigation and rainfed conditions. The objective of this study was to assess the effect of different doses of nitrogen and phosphorus in phenotypic characteristics and yield of three maize genotypes in two environments in the northern region of the state of Guerrero. The experiment was established in Iguala and Apaxtla, Guerrero during the spring-summer cycle - 2013. The genotypes were VS-535, A-7573 and V-537C. Nitrogen doses (100, 150 and 200 kg ha-1) and phosphorus (60, 90 and 120 kg ha-1), under a randomized complete block design with three replications in factorial arrangement. The experimental unit consisted of four rows of five meters length, row spacing 0.80 m. Recording: plant height, ear height, cob health, grain yield. The results indicated that in the four quantified variables, significant effects were detected. In Apaxtla, plant height, ear height, cob health and grain yield were higher than those observed in Iguala, Guerrero. Treatment nine (VS-535 + 200N + 120P) expressed greater cob health and grain yield. V-537C was higher in plant height and grain yield compared to VS-535 and A-7573, and the three genotypes were similar in height and cob health. The application of 200 units of N increased plant height and 90 units of P increased ear height, cob health and grain yield t ha-1.

Resumen El maíz es la principal fuente de alimento y es el cultivo que mayor superficie ocupa en México. En el estado de Guerrero existe gran diversidad de regiones agroecológicas que se distinguen por su altitud, temperatura, tipo de suelo, distribución de lluvias, donde los agricultores siembran híbridos, variedades y poblaciones nativas de maíz bajo condiciones de riego y temporal. El objetivo del presente trabajo fue examinar el efecto de diferentes dosis de nitrógeno y fósforo, en características fenotípicas y rendimiento de tres genotipos de maíz en dos ambientes de la región norte del estado de Guerrero. El experimento se estableció en Iguala y Apaxtla, Guerrero en el ciclo primavera verano - 2013. Los genotipos fueron VS-535, A-7573 y V-537C. Se estudiaron dosis de nitrógeno (100, 150 y 200 kg ha-1) y de fósforo (60, 90 y 120 kg ha-1), bajo un diseño experimental de bloques completos al azar con tres repeticiones en arreglo factorial. La unidad experimental fue de cuatro surcos de cinco metros de longitud, distancia entre surcos a 0.80 m. Se cuantificaron: altura de la planta, altura de mazorca, sanidad de la mazorca, rendimiento de grano. Los resultados indicaron que en las cuatro variables cuantificadas, se detectaron efectos significativos. En Apaxtla, la altura de planta, altura de mazorca, sanidad de la mazorca y rendimiento de grano fueron superiores a los observados en Iguala, Guerrero. El tratamiento nueve (VS-535+200N+120P) expresó mayor sanidad de mazorca y rendimiento de grano. La V-537C fue superior en altura de planta y rendimiento de grano respecto a VS-535 y A-7573, y fueron semejantes los tres genotipos en altura y sanidad de la mazorca. La aplicación de 200 unidades de N aumentó la altura de planta y 90 unidades de P incrementó la altura de mazorca, sanidad de la mazorca y rendimiento de grano t ha-1.

ABSTRACT INTRODUCTION For two decades, various countries have experienced an epidemic of chronic kidney disease unexplainable by traditional causes. Typically a chronic tubulointerstitial nephritis, it predominantly affects young male agricultural workers and has been reported in several countries in Central America, as well as in Sri Lanka, India and Egypt. Recent studies in El Salvador have also reported the disease in male nonagricultural workers and in women, both those working in agriculture and not. Epidemiological information on whether this condition affects pediatric populations is virtually nonexistent. Globally, estimates of chronic kidney disease prevalence in pediatric populations range from 21 to 108 per million population. OBJECTIVE Determine the prevalence of urinary markers of renal damage and of chronic kidney disease in persons aged <18 years in rural Salvadoran communities. METHODS Pediatric NefroSalva was a descriptive epidemiologic study in three agricultural regions with known high prevalence of chronic kidney disease of uncertain etiology: Bajo Lempa, Guayapa Abajo and Las Brisas. Demographic and health data were collected and physical measurements were taken for 2115 persons aged <18 years, 1058 boys and 1057 girls. Urine samples were tested for markers of renal damage and blood samples analyzed to measure creatinine for estimating glomerular filtration rate (Schwartz formula). Median glomerular filtration rate was compared with reference values for age groups 2-12 and 13-17 years; mean glomerular filtration rate trends were assessed for age groups 2-5, 6-12 and 13-17 years. Positive test results were confirmed after three months. RESULTS Prevalence of urinary markers of renal damage was 4%, 4.3% in girls and 3.8% in boys. Microalbuminura (albumin:creatinine ratio 30-300 mg/g) was detected in both sexes and all age groups in all three regions, with prevalences of 2.6%-3.8% in boys and 3.3%-3.8% in girls. Macroalbuminuria (albumin:creatinine ratio >300 mg/g) was detected only in girls in Las Brisas, 2.3%. Glomerular hyperfiltration (compared to international norms) was found in all age-sex groups in all three regions. Prevalence of chronic kidney disease was 3.9%—4.1% in girls and 3.6% in boys. The prevalence of chronic renal failure was 0.1%. CONCLUSIONS High prevalence of chronic kidney disease in children and adolescents calls attention to the need for primary prevention from very early ages. This finding in children in areas where chronic kidney disease of uncertain etiology is common in adults is consistent with a contribution of environmental toxins to the epidemic observed in these areas.

INTRODUCTION: For at least a decade, a chronic kidney disease unassociated with diabetes mellitus, hypertension or any of the more common traditional causes, has been reported in Salvadoran agricultural communities. OBJECTIVE: Characterize histopathology of chronic kidney disease of unknown etiology in patients from Salvadoran agricultural communities, describe renal damage associated with each disease stage, and assess associations between histopathological alterations and sociodemographic variables. METHODS: The study involved 46 patients of both sexes, aged ≥18 years. After clinical, laboratory and imaging examinations, kidney biopsies were performed and renal tissue assessed for interstitial fibrosis, tubular atrophy, interstitial inflammatory infiltration, sclerosis, increase in glomerular size and extraglomerular vascular lesions (according to the Banff 97 classification used for kidney transplant rejection). Special staining was done: Schiff periodic acid, Masson trichrome and methenamine silver. Immunofluorescence techniques were used to evaluate IgA, IgG, IgM, complement C1q and C3, fibrin, and kappa and lambda light chain deposits. RESULTS: The main findings were interstitial fibrosis and tubular atrophy with or without inflammatory monocyte infiltration. In addition, generalized sclerosis, increased glomerular size, collapse of some glomerular tufts, and lesions of extraglomerular blood vessels (such as intimal proliferation and thickening and vacuolization of the tunica media) were observed. Interstitial fibrosis and glomerulosclerosis were associated with male sex. Sugarcane workers showed more interstitial fibrosis and tubular atrophy and less glomerulomegaly than other occupational groups. CONCLUSION: The morphological pattern in all biopsies was one of chronic tubulointerstitial nephropathy with secondary glomerular and vascular damage, in different stages of evolution of chronic kidney disease, independent of age, sex or occupation.

The Chronic Kidney Disease between another non communicable and chronic disease, is a public health problem that needs a public health action plan. In this article have been analized the definition, classification and the risk progression factors for Chronic Kidney Disease. In this case, have been emphasized the necessity for a systematic approach to execute changes in the care of patients with a kidney disease and the multidisciplinary management of those patients by different physicians in order to stop the epidemic. Finally, It have been determined the strengths for the Cuban health system and its possibilites to make an early detection of Chronic Kidney Disease, and have been recommended an appropriate intervention to restrain and improve the present outcomes.

La Enfermedad Renal crónica y otras enfermedades crónicas no transmisibles son un problema mundial que requiere un plan de acción de salud. Se señala la definición, clasificación y los factores de riesgo de progresión de la enfermedad renal crónica. Se enfatiza la necesidad de efectuar mejoras y cambios en la atención médica a estos pacientes, por diferentes especialidades y en equipo multidisciplinario. Por último, se plantean las fortalezas del sistema de salud en Cuba para su detección temprana; efectuar intervenciones eficaces, y así contribuir a frenar la epidemia y mejorar los resultados actuales.

An epidemiological transition is ocurring throughout the world, leading to an increased morbidity and mortality by non-communicable diseases; in despite of the global characteristic of this phenomenon it is more accelerated in the emerging countries. Cardiovascular disease, cerebrovascular disease, diabetes mellitus, hypertension, macroangiopathy and chronic renal disease are among the main diseases. These diseases have in common that in their origin, progression to chronicity or their complications the vascular damage is presented and on the other hand shares the same risk factors. In this article is analysed the morbidity, mortality and the tendency of these diseases and the risks and transition risks that may influence in this epidemic health problem. A new paradigm integrating the concept of chronic vascular disease and estrategies for its prevention is proposed.

A nivel mundial, está ocurriendo un proceso de transición epidemiológica con un incremento de la morbilidad y la mortalidad por enfermedades no transmisibles y aunque el fenómeno es global es más acelerado en los países emergentes. Entre estas enfermedades se destacan la enfermedad cardio-vascular, la enfermedad cerebrovascular, la hipertensión arterial, la diabetes mellitus , la macroangiopatía y la enfermedad renal crónica. Estas enfermedades tienen en común que en su origen, progresión a la cronicidad y en sus complicaciones está presente el daño vascular y comparten los mismos factores de riesgo. En este artículo, se analiza la morbilidad, mortalidad y tendencia de estas enfermedades, los principales riesgos y la transición de éstos que están influyendo en este problema de salud epidémico. Se propone un nuevo paradigma integrador de <enfermedad vascular crónica> y un enfoque para su prevención.