Rentabilidad contable y EVA de la empresa colombiana constructora de otras obras de ingeniería civil

El objetivo de la investigación es evaluar la rentabilidad contable y el valor económico agregado de la constructora colombiana de otras obras de ingeniería civil en el período 2016-2021, mediante un método de análisis estático y de tendencias de indicadores contables y de gestión de valor Se encuentra que las ventas, activos y utilidad neta de la constructora fluctúan; logra rentabilidades sobre el patrimonio en cuatro años y en promedio, donde sobresale la eficacia en el control de costos y gastos como factor determinante en su comportamiento. No obstante, esta rentabilidad es menor que la constructora de mayores ventas en Colombia y aún más baja que la de su homóloga en países emergentes. Pese a las rentabilidades contables positivas de la constructora colombiana de otras obras de ingeniería civil, esta destruye valor económico agregado en cinco años y el valor de mercado agregado en el sexenio es negativo. Este resultado difiere al de la constructora afín en economías emergentes que crea valor económico agregado en cuatro años y el valor de mercado agregado es positivo en el sexenio. CLASIFICACIÓN JEL G30, L74, M4I

The objective of the research is to evaluate the accounting profitability and added economic value of the Colombian construction company of other civil engineering works in the period 2016-2021, through a method of static analysis and trends of accounting indicators and value management. The construction company's sales, assets, and net income are found to fluctuate; It achieves returns on equity in four years and on average, where efficiency in cost and expense control stands out as a determining factor in its behavior However this profitability is lower than that of the construction company with the highest sales in Colombia and even lower than that of its counterpart in emerging countries. Despite the positive accounting returns of the Colombian construction company of other civil engineering works, it destroys added economic value in five years and the added market value in the six years is negative. This result differs from that of the similar construction company in emerging economies, which creates added economic value in four years and the added market value is positive in six years. JEL CLASSIFICATION G30, L74, M4I

O objetivo da pesquisa é avaliar a rentabilidade contabilística e o valor econômico agregado da construtora colombiana de outras obras de engenharia civil no período 2016-2021, através de um método de análise estática e tendências de indicadores contábeis e gestão de valor. As vendas, os ativos e o lucro líquido da construtora flutuam; Obtém rentabilidade sobre o patrimônio em quatro anos e em média, onde a eficiencia no controle de custos e despesas se destaca como fator determinante em seu comportamento. No entanto, essa rentabilidade é inferior à da construtora com maior faturamento na Colômbia e ainda inferior à de sua congênere nos países emergentes. Apesar dos retornos contábeis positivos da construtora colombiana de outras obras de engenharia civil, ela destrói valor econômico agregado em cinco anos e o valor agregado de mercado em seis anos é negativo. Esse resultado difere do da construtora similar nas economias emergentes, que cria valor econômico agregado em quatro anos e o valor agregado de mercado é positivo em seis anos. CLASSIFICAÇÃO JEL G30, L74, M41

Implementation of the updated Sydney system biopsy protocol improves the diagnostic yield of gastric preneoplastic conditions: Results from a real-world study.

BACKGROUND: The updated Sydney system biopsy protocol (USSBP) standardizes the sampling of gastric biopsies for the detection of preneoplastic conditions (e.g., gastric intestinal metaplasia [GIM]), but the real-world diagnostic yield is not well-described. AIM: To determine whether regular application of USSBP is associated with higher detection of chronic atrophic gastritis (CAG), GIM and autoimmune gastritis (AIG). METHODS: We performed a real-world retrospective study at an academic urban tertiary hospital in Chile. We manually reviewed medical records from consecutive patients undergoing esophagogastroduodenoscopy (EGD) from January to December 2017. Seven endoscopists who performed EGDs were categorized into two groups (USSBP 'regular' and USSBP 'infrequent') based on USSBP adherence, using minimum 20% adherence as the prespecified threshold. Multivariable logistic regression models were used to estimate the odds ratios (aOR) and 95% confidence intervals (CI) for the association between endoscopist groups and the likelihood of diagnosing CAG, GIM or AIG. RESULTS: 1206 patients were included in the study (mean age: 58.5; 65.3% female). The USSBP regular group demonstrated a higher likelihood of detecting CAG (20% vs. 5.3%; aOR 4.03, 95%CI: 2.69-6.03), GIM (12.2% vs. 3.4%; aOR 3.91, 95%CI: 2.39-6.42) and AIG (2.9% vs. 0.8%; aOR 6.52, 95%CI: 1.87-22.74) compared to infrequent group. Detection of advanced-stage CAG (Operative Link for Gastritis Assessment stage III/IV) was significantly higher in the USSBP regular vs. infrequent group (aOR 5.84, 95%CI: 2.23-15.31). CONCLUSIONS: Routine adherence to USSBP increases the detection rates of preneoplastic conditions, including CAG, GIM and AIG. Standardized implementation of USSBP should be considered in high gastric cancer risk populations.

Evaluation of trefoil factor 3 as a non-invasive biomarker of gastric intestinal metaplasia and gastric cancer in a high-risk population.

BACKGROUND: Adenocarcinoma is preceded by chronic atrophic gastritis, gastric intestinal metaplasia and dysplasia. Trefoil factor 3 (TFF3) is a peptide secreted by goblet cells, which is abundantly present in intestinal metaplasia. AIM: To evaluate the utility of serum TFF3 as a non-invasive biomarker for the diagnosis of intestinal metaplasia and gastric cancer. METHODS: Single-center, cross-sectional study of 274 patients who consecutively underwent upper gastrointestinal endoscopy with gastric biopsies (updated Sydney system). TFF3 levels were measured in serum by a commercial ELISA kit. Patients with normal histology or chronic atrophic gastritis without intestinal metaplasia comprised the control group. In addition, 14 patients with invasive gastric cancer were included as a reference group. The association between TFF3 levels and intestinal metaplasia was assessed by logistic regression. RESULTS: Patients with intestinal metaplasia (n=110) had a higher median TFF3 level as compared to controls (n=164), 13.1 vs. 11.9ng/mL, respectively (p=0.024). Multivariable logistic regression showed a no significant association between TFF3 levels and intestinal metaplasia (OR=1.20; 95%CI: 0.87-1.65; p-trend=0.273). The gastric cancer group had a median TFF3 level of 20.5ng/mL, and a significant association was found (OR=3.26; 95%CI: 1.29-8.27; p-trend=0.013). CONCLUSION: Serum levels of TFF3 do not discriminate intestinal metaplasia in this high-risk Latin American population. Nevertheless, we confirmed an association between TFF3 levels and invasive gastric cancer.

Identification of anti-Helicobacter pylori antibody signatures in gastric intestinal metaplasia.

BACKGROUND: Chronic Helicobacter pylori infection may induce gastric intestinal metaplasia (IM). We compared anti-H. pylori antibody profiles between IM cases and non-atrophic gastritis (NAG) controls. METHODS: We evaluated humoral responses to 1528 H. pylori proteins among a discovery set of 50 IM and 50 NAG using H. pylori protein arrays. Antibodies with ≥ 20% sensitivity at 90% specificity for either group were selected and further validated in an independent set of 100 IM and 100 NAG using odds ratios (OR). A validated multi-signature was evaluated using the area under the receiver operating characteristics curve (AUC) and net reclassification improvement (NRI). RESULTS: Sixty-two immunoglobulin (Ig) G and 11 IgA antibodies were detected in > 10%. Among them, 22 IgG and 6 IgA antibodies were different between IM and NAG in the discovery set. Validated antibodies included 11 IgG (anti-HP1177/Omp27/HopQ [OR = 8.1, p < 0.001], anti-HP0547/CagA [4.6, p < 0.001], anti-HP0596/Tipα [4.0, p = 0.002], anti-HP0103/TlpB [3.8, p = 0.001], anti-HP1125/PalA/Omp18 [3.1, p = 0.001], anti-HP0153/RecA [0.48, p = 0.03], anti-HP0385 [0.41, p = 0.006], anti-HP0243/TlpB [0.39, p = 0.016], anti-HP0371/FabE [0.37, p = 0.017], anti-HP0900/HypB/AccB [0.35, p = 0.048], and anti-HP0709 [0.30, p = 0.003]), and 2 IgA (anti-HP1125/PalA/Omp18 [2.7, p = 0.03] and anti-HP0596/Tipα [2.5, p = 0.027]). A model including all 11 IgG antibodies (AUC = 0.81) had better discriminated IM and NAG compared with an anti-CagA only (AUC = 0.77) model (NRI = 0.44; p = 0.001). CONCLUSIONS: Our study represents the most comprehensive assessment of anti-H. pylori antibody profiles in IM. The target antigens for these novel antibodies may act together with CagA in the progression to IM. Along with other biomarkers, specific H. pylori antibodies may identify IM patients, who would benefit from surveillance.

Proposal of minimum elements for screening and diagnosis of gastric cancer by an international Delphi consensus.

The World Endoscopy Organization Stomach and Duodenal Diseases Committee extracted minimum elements for screening and diagnosis of gastric cancer (GC) in aim to support countries that do not have national guidelines on screening and diagnosis of GC. Current national or international guidelines were collected worldwide and recommendations were classified according to the quality of evidence and were finalized through a modified Delphi method. The minimum elements consist of seven categories: [1] Extraction of high-risk patients of GC before esophagogastroduodenoscopy (EGD), [2] Patients who need surveillance of GC, [3] Method to ensure quality of EGD for detection of GC, [4] Individual GC risk assessment by EGD, [5] Extraction of high-risk patients of GC after EGD [6] Qualitative or differential diagnosis of GC by EGD, and [7] Endoscopic assessment to choose the therapeutic strategy for GC. These minimum elements will be a guide to promote the elimination of GC among countries with a high incidence of GC who lack national guidelines or screening programs.

Cuaderno complementario sobre Estudio de la ideología y la política para técnicos de la salud / Complementary notebook about the Study of ideology and policy for health technicians

RESUMEN Fundamento: en las carreras de las ciencias técnicas que se estudian en las universidades médicas se imparte la asignatura Estudio de la Ideología y la Política con el fin de enseñar al estudiante el devenir histórico-lógico del pueblo cubano, y su ejemplo y trascendencia para el mundo. Objetivo: elaborar un cuaderno complementario para el trabajo independiente de los estudiantes con actividades de carácter desarrollador y de evaluación del aprendizaje. Métodos: se realizó una investigación de desarrollo en la Filial de Ciencias Médicas "Dr. Eusebio Hernández Pérez" en Colón, Matanzas, durante los cursos escolares 2016-2017 y 2017-2018. Se utilizaron métodos teóricos: analítico-sintético, inductivo-deductivo y sistémico-estructural; y empíricos: análisis documental del programa y las orientaciones metodológicas, y encuesta en forma de entrevista a profesores para corroborar si la bibliografía recomendada era suficiente para el cumplimiento de los objetivos previstos y si favorece el estudio independiente de los contenidos de la asignatura. El cuaderno fue valorado por criterio de especialistas. Resultados: se evidenció un déficit bibliográfico para su estudio, sus contenidos están dispersos en varios textos lo cual dificulta el trabajo independiente de los estudiantes, por lo que fue confeccionado un cuaderno complementario que contiene tres unidades y varias actividades en correspondencia con el cumplimiento de los objetivos del programa. Conclusiones: el material contribuye a solucionar las insuficiencias detectadas y fue valorado por criterio de especialistas como pertinente, novedoso y útil; constituye una herramienta esencial para apoyar el trabajo independiente de los estudiantes y la evaluación del aprendizaje.

ABSTRACT Background: in technical science careers that are studied in medical universities, the Study of Ideology and Politics subject is taught with the aim of teaching the historical-logical evolution of the Cuban people, and its example and transcendence for the world, to the students. Objective: to create a supplementary notebook for the independent work of students with activities of developmental character and learning evaluation. Methods: at the "Dr. Eusebio Hernández Pérez" Medical Sciences Subsidiary in Colón, Matanzas, a development research was carried out during the 2016-2017 and 2017-2018 academic years. Theoretical methods were used: analytical-synthetic method, inductive-deductive method and systemic-structural method; and empirical methods: documentary analysis of the program and the methodological guidelines, and an interview survey with teachers to verify whether the recommended bibliography was sufficient for the fulfillment of the foreseen objectives and whether it helps the independent study of the subject contents. The supplementary notebook was evaluated according to the criteria of specialists. Results: for this study a bibliographical deficit was evident, contents were scattered in several texts which made the independent work of students difficult, so a supplementary notebook which contains three units and several activities was made in such a way the objectives of the program were fulfilled. Conclusions: the supplementary notebook contributes to solve the insufficiencies were found and it was valued by specialists as pertinent, novel and useful; it is an essential tool to support the independent work of students and learning assessment.

Principles and practice to facilitate complete photodocumentation of the upper gastrointestinal tract: World Endoscopy Organization position statement.

Although esophagogastroduodenoscopy (EGD) is the most commonly used procedure in the gastrointestinal (GI) tract, the method of esophageal, gastric and duodenal mucosa photodocumentation varies considerably worldwide. One probable explanation is that for generations, EGD has primarily been taught by GI faculty and instructors based on their perceptions and experience, which has resulted in EGD being a non-standardized procedure. Currently, the procedure is facing a challenging scenario as endoscopy societies are implementing procedure-associated quality indicators aiming for best practice among practitioners and evidence-based care for patients. Contrary to colonoscopy where cecum landmarks photodocumentation is considered proof of completeness, there are currently no reliable performance measures to gauge the completeness of an upper endoscopy nor guidance for complete photodocumentation. This World Endoscopy Organization (WEO) position statement aims to provide practical guidance to practitioners to carry out complete EGD photodocumentation. Hence, an international group of experts from the WEO Upper GI Cancer Committee formulated the following document using the body of evidence established through literature reviews, expert opinions, and other scientific sources. The group acknowledged that although the procedure should be feasible in any facility, what is needed to achieve a global shift on the concept of completeness is a common written statement of agreement on its potential impact and added value. This best practice statement offers endoscopists principles and practical guidance in order to carry out complete photodocumentation from the hypopharynx to the second duodenal portion.

Use of N-acetylcysteine plus simethicone to improve mucosal visibility during upper GI endoscopy: a double-blind, randomized controlled trial.

BACKGROUND AND AIM: Upper GI endoscopy (UGE) is essential for the diagnosis of gastrointestinal diseases. Mucus and bubbles may decrease mucosal visibility. The use of mucolytics could improve visualization. Our aim was to determine whether premedication with simethicone or simethicone plus N-acetylcysteine is effective in improving visibility during UGE. METHODS: This was a randomized, double-blinded, placebo-controlled trial with 2 control groups: no intervention and water 100 mL (W); and 3 intervention groups: simethicone 200 mg (S); S + N-acetylcysteine (NAC) 500 mg (S+NAC500); and S + NAC 1000 mg (S+NAC1000). The solution was ingested 20 minutes before UGE. Gastric visibility was evaluated in 4 segments with a previously described scale. A score of less than 7 points was defined as adequate visibility (AV). Water volume was used to improve visibility, and adverse reactions were evaluated as a secondary outcome. Multiple group comparison was performed using non-parametric one-way analysis of variance (ANOVA). RESULTS: Two hundred thirty patients were included in the study, 68% female, mean age 49 years. The most common indication for UGE was epigastric pain/dyspepsia (33%). AV was more frequent in the S+NAC500 and S+NAC1000 groups (65% and 67%) compared with no intervention (44%, P = .044) and water (41%, P = .022). The gastric total visibility scale (TVS) was significantly better in the S+NAC500 and S+NAC1000 groups compared with water (P = .03 and P = .008). Simethicone was not different from no intervention and water. S+NAC1000 required less water volume to improve visibility. No adverse reactions from the study drugs were observed. CONCLUSIONS: Premedication with S+NAC500 and S+NAC1000 improves visibility during UGE. The use of simethicone did not show improvements in gastric visibility. TVS was worse in patients using water alone. (Clinical trial registration number: NCT 01653171.).

[Recommendations of the Chilean Association for Digestive Endoscopy for the management of gastric pre-malignant lesions]. / Diagnóstico precoz de cáncer gástrico: Propuesta de detección y seguimiento de lesiones premalignas gástricas: protocolo ACHED.

An expert panel analyzed the available evidence and reached a consensus to release 24 recommendations for primary and secondary prevention of gastric cancer (CG) in symptomatic patients, with indication for upper GI endoscopy. The main recommendations include (1) Search for and eradicate H. pylori infection in all cases. (2) Systematic gastric biopsies (Sydney protocol) in all patients over 40 years of age or first grade relatives of patient with CG, to detect gastric atrophy, intestinal metaplasia or dysplasia. (3) Incorporate the OLGA system (Operative Link on Gastritis Assessment) to the pathological report, to categorize the individual risk of CG. (4) Schedule endoscopic follow-up according to the estimated risk of CG, namely annual for OLGA III- IV, every 3 years for OLGA I- II or persistent H. pylori infection, every 5 years for CG relatives without other risk factors and no follow-up for OLGA 0, H. pylori (-). (4) Establish basic human and material resources for endoscopic follow-up programs, including some essential administrative processes, and (5) Suggest the early CG/total CG diagnosis ratio of each institution and the proportion of systematic recording of endoscopic images, as quality indicators. These measures are applicable using currently available resources, they can complement any future screening programs for asymptomatic population and may contribute to improve the prognosis of CG in high-risk populations.

Finger chondroid syringoma as a hypoechoic subcutaneous nodule in ultrasound.

Chondroid syringoma (CS) is an uncommon, benign epithelial skin mixed tumor. It is often located in the head and neck and is unusual in other parts of the body. It may be seen as a skin or soft tissue tumor. We present findings on high-resolution ultrasound and histology in a case of benign CS located on the right index finger. High-resolution ultrasound showed a solid hypoechoic, well-defined subcutaneous mass, adjacent to the tendon. Complete surgical excision was performed, and histopathology demonstrated an apocrine mixed tumor (CS). Although CS histological findings are well described, radiological features have been reported only in few cases and mainly in magnetic resonance. Chondroid syringoma should be suspected by high-resolution ultrasound as a differential diagnosis for a solid slow-growing soft tissue nodule in a finger, especially if the lesion has no contact with the underlying tendon.

Non-alcoholic fatty liver disease and its association with obesity, insulin resistance and increased serum levels of C-reactive protein in Hispanics.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a metabolic disorder of the liver, which may progress to fibrosis or cirrhosis. Recent studies have shown a significant impact of ethnicity on susceptibility to steatosis-related liver disease. AIMS: To estimate the prevalence of NAFLD among Chilean Hispanics as well as the clinical and biochemical variables associated with the disease. METHODS: Population-based study among Chilean Hispanics. The diagnosis of NAFLD was made on the basis of ultrasound evidence of fatty liver and absence of significant alcohol consumption and hepatitis C virus infection. RESULTS: A total of 832 Hispanic subjects were included. Ultrasound findings revealed diffuse fatty liver in 23% of the subjects. Variables associated with fatty liver in multivariate analysis were body mass index >26.9 [odds ratio (OR) 6.2; 95% confidence interval (CI) 3.3-11.5], abnormal aspartate aminotransferase levels (OR 14; 95% CI 8.2-23.7), presence of insulin resistance as measured by homoeostasis model assessment-insulin resistance (OR 3; 95% CI 1.8-4.8) and serum levels of high-sensitivity C-reactive protein (hs-CRP) greater than 0.86 mg/L (OR 2.9; 95% CI 1.6-5.2). Among subjects with NAFLD, levels of hs-CRP were similar regardless of the alanine aminotransferase (ALT) level. CONCLUSIONS: Chilean Hispanics exhibit a high prevalence of NAFLD. Obesity, insulin resistance, abnormal aminotransferase levels and elevated hs-CRP were independently associated with the presence of NAFLD. ALT elevation underestimates the presence of ultrasonographical fatty liver, whereas hs-CRP is a sensitive independent marker of NAFLD, which may be useful for detecting fatty liver in the general population.

[Chemoembolization of hepatocarcinoma: report of two cases]. / Quimioembolización hepática en el manejo terapéutico del hepatocarcinoma: Reporte de dos casos.

Chemoembolization is a therapeutic alternative for those patients with hepatocarcinoma that cannot be excised surgically or that are waiting a liver allograft. We report two patients with hepatocarcinoma who were subjected to chemoembolization. A 65 years old male with a chronic liver disease and right lobe hepatocarcinoma, waiting for a liver transplantation, was subjected to two sessions, of chemoembolization four weeks apart. A magnetic resonance showed a 80% reduction of tumor volume one month later. A 72 years old diabetic male with an alcoholic liver disease with two hepatocarcinoma in the right lobe was subjected to two sessions of chemoembolization, separated by four weeks. A magnetic resonance one month later showed the absence of blood flow in both lesions, suggesting complete necrosis.

Quimioembolización hepática en el manejo terapéutico del hepatocarcinoma: Reporte de dos casos / Chemoembolization of hepatocarcinoma: Report of two cases

Chemoembolization is a therapeutic alternative for those patients with hepatocarcinoma that cannot be excised surgically or that are waiting a liver allograft. We report two patients with hepatocarcinoma who were subjected to chemoembolization. A 65 years old male with a chronic liver disease and right lobe hepatocarcinoma, waiting for a liver transplantation, was subjected to two sessions, of chemoembolization four weeks apart. A magnetic resonance showed a 80 percent reduction of tumor volume one month later. A 72 years old diabetic male with an alcoholic liver disease with two hepatocarcinoma in the right lobe was subjected to two sessions of chemoembolization, separated by four weeks. A magnetic resonance one month later showed the absence of blood flow in both lesions, suggesting complete necrosis.

Successful liver transplantation and delivery in a woman with fulminant hepatic failure occurring during the second trimester of pregnancy.

BACKGROUND: Severe liver dysfunction occurring during pregnancy is an unusual but dramatic event that poses special technical and ethical issues because it involves two lives. METHODS AND RESULTS: We report the case of a 35-year-old woman with cryptogenic fulminant hepatic failure who underwent successful orthotopic liver transplantation at 22 weeks of pregnancy. After a relatively uneventful post-operative course she delivered a normal offspring at the 27th week of gestation. There were no obstetrical complications and neonatal outcome was excellent. After a year of follow-up, the patient is doing well,and the newborn has exhibited normal psychomotor and weight/height development. CONCLUSION: This case illustrates the challenge of treating fulminant hepatic failure during pregnancy and demonstrates that liver transplantation is a feasible therapeutic option for treatment of patients with this condition, allowing successful completion of pregnancy.

Gallbladder disease is associated with insulin resistance in a high risk Hispanic population.

BACKGROUND/AIMS: We tested whether cholesterol gallstone disease (GS) is associated to insulin resistance and serum C-reactive protein (CRP) in a high risk population. METHODS: This was a nested case-control study on 881 Chilean subjects that included clinical examination, abdominal ultrasound and blood chemistries. Insulin resistance was determined by the homeostasis model assessment index (IR-HOMA). RESULTS: Compared to controls (n = 582), age and sex adjusted median IR-(HOMA) was significantly elevated in subjects with GS (n = 299) (P < 0.001). Risks of GS in subjects with insulin resistance and different body mass index (BMI) were: BMI < 25, 2.2 (1.1-4.7); BMI 25-30, 1.5 (0.9-2.5) and BMI > 30, 1.7 (1.0-2.9). Risk of GS in subjects with metabolic syndrome was 1.7 (CI, 1.2-2.5) and with fatty liver, 1.5 (1.1-2.2). Risk of GS in subjects with CRP > 1 mg/dL was 1.0 (0.7-1.7). CONCLUSIONS: GS is associated to insulin resistance, fatty liver and to metabolic syndrome, but not to serum CRP in a high risk Hispanic population. Insulin resistance could have a major role in the pathogenesis of GS favoring the production of cholesterol supersaturated bile and altering gallbladder function.

Incidence and prevalence of hepatitis C virus infection in Chile.

UNLABELLED: Chronic hepatitis C is a major cause of liver-related morbidity and mortality. Epidemiological data regarding this infection in developing countries is scanty. METHODS: Prevalence of hepatitis C (HCV) infection was investigated in a random sample of Chilean general adult population older than 20 years of age. Additionally, frequency of HCV infection was assessed in group of native Chilean Amerindians (Mapuche Indians) living in an isolated locality of the Southern Chile. Incidence of HCV infection was estimated using serum samples separated by 7 years (1993-2000). RESULTS: Among 959 subjects, prevalence of anti-HCV antibodies was 1.15% (95% CI 0.48-1.82%) and 0.83% when only RIBA-confirmed cases were considered. Among these subjects, 62.5% had detectable HCV RNA in serum and 40% of them had a history of blood transfusion. Age distribution of cases showed a steadily increasing prevalence with age. Estimated incidence of new HCV infections was 15 per 100,000 subjects per year in the period 1993-2000. No cases were detected among the 145 Mapuche subjects studied. CONCLUSIONS: HCV infection is a prevalent disease in the Hispanic population of Chile with a low incidence in the last decade, whereas it was not detected in an isolated Mapuche Indian community. Age distribution of prevalence suggests that the peak of infection in Chile occurred 30 to 50 years ago.