Abstract Bovine leukosis is caused by an oncogenic virus of the genus Deltaretrovirus, causing losses associated with decreased production indicators and restrictions on exports of cattle and cattle products. The disease has a prolonged incubation period of between 1–5 years and the antibodies can be detected 2–3 weeks post infection. The disease can present asymptomatically, and develop persistent lymphocytosis or lymphosarcoma. The objective of this study was to estimate the prevalence and risk factors associated with bovine leukosis in Villavicencio, Colombia. Blood samples were taken from 636 animals, and obtained randomly from 24 herds. The samples were analysed using a Competition ELISA kit for the detection of anti-gp51 antibodies. Information on possible risk factors was collected, then OR and X2 were calculated, and statistically significant with p < 0.05 variables were included in a linear regression multivariate analysis. The general seroprevalence was 24.6% and the herd seroprevalence was 83.3%. The seroprevalence was 21.3% in males and 25.0% in females. The risk factors identified were abortion, non-bearing cows, artificial insemination, and use of common needles, Creole breed and participation in cattle exhibitions. The study confirmed the presence of bovine leukosis associated with reproductive and management factors.

Resumo A leucose bovina é causada por um vírus oncogênico do gênero Deltaretrovirus, causando prejuízos associados à queda dos indicadores produtivos e restrições à exportação de bovinos e derivados.Adoença tem um período de incubação prolongado entre 1 e 5 anos e os anticorpos podem ser detectados 2 a 3 semanas após a infecção. A doença pode se apresentar de forma assintomática, e evoluir para linfocitose persistente ou linfossarcoma. O objetivo do estudo foi estimar a prevalência e os fatores de risco associados à leucose bovina em Villavicencio, Colômbia. Amostras de sangue foram coletadas de 636 animais, obtidos aleatoriamente de 24 rebanhos.As amostras foram analisadas com o kit Competition ELISA para detecção de anticorpos anti-gp51. Foram coletadas informações sobre possíveis fatores de risco, se realizo um analise univariado entre as variáveis e a presença da seropositividad a leukosis bovina mediante o cálculo do OR e X2, as variáveis estatisticamente significativas com p<0,05 foram incluídas em uma análise multivariada de regressão linear. A soroprevalência geral foi de 24,6% e a soroprevalência do rebanho foi de 83,3%.Asoroprevalência foi de 21,3% em machos e 25,0% em fêmeas. Os fatores de risco identificados foram: aborto, vacas não reprodutivas, inseminação artificial e uso de agulha comum, raça crioula e exposições de gado. O estudo confirmou a presença de leucose bovina associada a fatores reprodutivos e de manejo.

Abstract Objective: Determining the appropriate approach for delivery after previous cesarean is a very controversial issue. Our objective was to establish whether pregnant women with a previous cesarean have an increased maternal and fetal morbidity and mortality after attempting vaginal delivery as well as to determine which factors may influence the achievement of a vaginal birth after cesarean. Materials and methods: A retrospective observational cohort study including 390 patients (196 cesarean group and 194 nulliparous group) was carried out. We compared neonatal and maternal outcomes between groups. Afterward, a multivariate logistic regression was applied for our second objective. Results: There were higher rates of uterine rupture (2% vs. 0%, p: 0.045) and puerperal hemorrhage (9.7% vs. 3.1%, p: 0.008) in the cesarean group and lower vaginal delivery rate (58.2% vs. 77.8%, p < 0.0005). We found that the induced onset of labor (OR = 2.9) and new born weight (OR = 1.0001) were associated with an increased risk of cesarean section. Conclusions: Our findings stress the need for further investigations in this field, which might provide a basis for a better management of patients with a previous cesarean.

Abstract Introduction: disease-related malnutrition (DRM) is a specific type of malnutrition caused by the inflammatory response to the underlying disease. Its prevalence worldwide varies from 30 % to 50 %, being similar in Spanish hospitals. DRE is not commonly recognized but is usually misdiagnosed and generally not treated. It is associated with an increased risk of morbidity, mortality, and costs. Nutritional societies recommend that screening be performed within the first 24 to 48 hours after admission for the early detection of malnutrition. No screening tool is universally accepted. Objectives: to evaluate the predictive validity (hospital stay, complications, readmissions and mortality) of the CONUT method as compared to SGA and NSA. Material and method: a retrospective study included in a prospective observational study of 365 hospitalized patients from July to December 2012. Results: the most frequent admission services were Internal Medicine and Oncology (30.7 % and 29.3 %). Moderate and severe risk of malnutrition: CONUT, 42.2 % and 12.1 %, SGA 25.8 % and 10.1 %, and NSA 13.7 % and 14.5 %. Malnutrition evaluated using the CONUT method was significantly related to complications (p = 0.036), readmissions (p = 0.041) and mortality (p = 0.007). The ROC curves for mortality, for all the methods evaluated, showed that CONUT is the best tool. Conclusions: CONUT is an automatic detection tool that can be used as a first step in the diagnosis risk of malnutrition. CONUT offers the advantage of being a prognostic factor for complications, readmission, and mortality.

Resumen Introducción: la desnutrición relacionada con la enfermedad (DRE) es un tipo específico de desnutrición producida por la respuesta inflamatoria de la enfermedad de base. Su prevalencia en todo el mundo varía del 30 al 50 %, siendo similar en los hospitales españoles. La DRE no se reconoce comúnmente, se diagnostica inadecuadamente y generalmente no se trata. Se asocia a un mayor riesgo de morbilidad, mortalidad y costes. Las sociedades nutricionales recomiendan que el cribado se realice en las primeras 24 a 48 horas posteriores al ingreso para la detección temprana de la desnutrición. Ninguna herramienta de cribado se acepta universalmente. Objetivos: evaluar la validez predictiva (estancia hospitalaria, complicaciones, reingresos y mortalidad) del método CONUT en comparación con la VGS y el VEN. Material y método: estudio retrospectivo incluido en un prospectivo observacional de 365 pacientes hospitalizados de julio a diciembre de 2012. Resultados: los servicios de ingreso más frecuentes fueron Medicina Interna y Oncología (30,7 % y 29,3 %). Detección de los riesgos moderado y severo de desnutrición: CONUT, 42,2 y 12,1 %; VSG, 25,8 % y 10,1 %; VEN, 13,7 y 14,5 %. La desnutrición evaluada utilizando el método CONUT se relacionó significativamente con las complicaciones (p = 0,036), los reingresos (p = 0,041) y la mortalidad (p = 0,007). Las curvas ROC de la mortalidad, para todos los métodos evaluados, mostraron que CONUT es la mejor herramienta. Conclusiones: CONUT es una herramienta de detección automática que se puede utilizar como primer paso en el diagnóstico del riesgo de desnutrición. CONUT ofrece la ventaja de ser un factor pronóstico de complicaciones, reingreso y mortalidad.

Abstract Introduction: disease-related malnutrition has a high prevalence, with clinical consequences potentially severe for the patient, and of high economic impact for the healthcare system. Objective: to perform a review of the literature regarding the economic burden of disease-related malnutrition, to assess complications, and to determine the usefulness of enteral or oral nutritional supplementation from a cost analysis perspective. Methods: a review of the literature up to June 2016 was carried out regarding economic costs of disease-related malnutrition and cost analysis of nutritional treatment, with special focus on retrieval of systematic reviews, meta-analysis, and randomized clinical trials. Results: a total of 31 publications were selected, 15 on costs of disease-related malnutrition and 16 on costs of treatment. Disease-related malnutrition increases health care costs in relation to a longer hospital stay, higher incidence of infectious and non-infectious complications, greater need of treatment, increase in readmissions, more prolonged stay in the intensive care unit and/or the need of referral to continuing care centers at discharge. Publications regarding treatment with oral nutritional supplements suggest that these oral supplements are cost-effective and cost-beneficial both in ambulatory and hospitalized patients. Conclusions: disease-related malnutrition causes an increase in health care costs that could be minimized, among other approaches, by an early diagnosis and treatment for which oral nutritional supplements are cost-effective and cost-beneficial.

Resumen Introducción: la desnutrición relacionada con la enfermedad tiene una elevada prevalencia, con consecuencias clínicas potencialmente graves para el paciente y de alto impacto económico para el sistema sanitario. Objetivos: realizar una revisión de la literatura sobre los costes económicos de la desnutrición asociada a la enfermedad, analizar sus complicaciones y evaluar la utilidad de la nutrición enteral u oral bajo la perspectiva del análisis de costes. Métodos: se llevó a cabo una revisión de la literatura hasta junio de 2016 sobre los costes económicos de la desnutrición y el análisis de costes del tratamiento nutricional, priorizando las revisiones sistemáticas, los metaanálisis y los ensayos clínicos aleatorizados. Resultados: se identificaron 31 publicaciones, 15 sobre los costes de la desnutrición relacionada con la enfermedad y 16 de análisis de costes del tratamiento. La desnutrición relacionada con la enfermedad incrementa los costes sanitarios por una mayor estancia hospitalaria, mayor incidencia de complicaciones infecciosas y no infecciosas, mayor necesidad de tratamientos, incremento de los reingresos, estancias más prolongadas en unidades de cuidados intensivos y/o la necesidad de derivación al alta a centros de continuación de cuidados. Las publicaciones evaluadas sobre el tratamiento mediante suplementos nutricionales orales sugieren que los suplementos nutricionales orales son coste-efectivos y coste-útiles tanto en pacientes ambulatorios como en pacientes hospitalizados. Conclusiones: la desnutrición relacionada con la enfermedad produce un incremento de los costes sanitarios que podría minimizarse, entre otras formas, mediante un diagnóstico y tratamiento precoz de la misma, para lo cual los suplementos nutricionales orales constituyen una herramienta coste-eficaz y coste-útil.

Resumen Introducción. La ley de Zipf/Mandelbrot establece una auto-organización fractal de fenómenos como el lenguaje, el repertorio inmune B y T, la dinámica cardiaca fetal, entre otros. La teoría de la probabilidad ha permitido desarrollar predicciones en distintos campos de la medicina. Objetivo. Realizar una aplicación de la ley de Zipf/Mandelbrot y la teoría de probabilidad a la caracterización de reacciones adversas a medicamentos en pacientes adultos mayores. Materiales y métodos. Las tasas de incidencias de reacciones adversas a medicamentos (RAM) y problemas relacionados con medicamentos (PRM) en adultos mayores de 44 años en Bogotá, Colombia, de enero a diciembre de 2012 fueron analizadas mediante la ley Zipf-Mandelbrot, agrupando las edades por rangos cada 5 años. Adicionalmente, se evaluó la probabilidad del número de reportes de los 10 grupos farmacológicos que generan mayor número de RAM y PRM. Resultados. Las tasas de incidencia de RAM y PRM presentan un comportamiento fractal estadístico con dimensión fractal de 0,983 y un R2 de 0,8618. La probabilidad de los grupos farmacológicos varió entre 0,0383 para los anticonvulsivos e hipolipemiantes y 0,2743 para antibacterianos. Las probabilidades de los grupos farmacológicos evidencian diferencias de 10 en órdenes de magnitud respecto a la máxima probabilidad. Conclusión. La tasa de incidencia de RAM y PRM es caracterizada mediante la ley de Zipf/Mandelbrot; se encontró un comportamiento no equiprobable de la distribución de reportes por grupos farmacológicos, que podría evidenciar tendencias útiles en la vigilancia farmacológica.

Abstract Introduction. Zipf/Mandelbrot Law establishes a fractal auto-organization of phenomena such as language, the B and T immune repertoire and the fetal cardiac behavior, among other possible applications. Objective. The application of the probability theory has allowed the prediction of the cardiac behavior, epidemics and the union of peptides in molecular biology. Materials and methods. The adverse reactions rate to medications (ARM) and problems related to medications (PRM) in adults above 44 years of age in Bogotá, Colombia, from January to December, 2012, were analyzed by means of the Zipf- Mandelbrot law, separating the ages by ratios every 5 years. Additionally, the probability of the number of reports of the 19 pharmacological groups with higher ARM and PRM were assessed. Results. The ARM and PRM rates have a fractal statistic behavior with fractal dimension of 0,983 and a R2 of 0,8618. The probability of the pharmacological groups varied between 0,0383 for anticonvulsants and lipid-lowering medications and 0,2743 for anti-bacterial ones. The probabilities of the pharmacological groups show differences of 10 in magnitude orders in regard to the maximum probability. Conclusion. The incidence rate of RAM and PRM is characterized by Zipf/Mandelbrot law; It was found a not equiprobable behavior of the distribution of reports by pharmacological groups, which could show useful trends in pharmacological surveillance.

Resumo Introdução. A lei de Zipf/Mandelbrot estabelece uma auto-organização fractal de fenômenos como a linguagem, o repertório imune B e T, a dinâmica cardíaca fetal, entre outras aplicações. Objetivo. Aplicar a teoria da probabilidade há permitido desenvolver predições na dinâmica cardíaca, epidemias, e união de peptídeo em biologia molecular. Materiais e métodos. As taxas de incidências de reações adversas a medicamentos (RAM) e problemas relacionados com medicamentos (PRM) em adultos maiores de 44 anos em Bogotá, Colômbia, de Janeiro a dezembro de 2012 foram analisadas mediante a lei Zipf-Mandelbrot, agrupando as idades por faixa de cada 5 anos. Adicionalmente se avaliou a probabilidade do número de relatórios dos 10 grupos farmacológicos que geram maior número de RAM e PRM. Resultados. As taxas de incidência de RAM e PRM apresentam um comportamento fractal estatístico com dimensão fractal de 0,983 e um R2 de 0,8618. A probabilidade dos grupos farmacológicos variou entre 0,0383 para os anti-convulsivos e hipolipemiantes, e 0,2743 para antibacterianos. As probabilidades dos grupos farmacológicos evidenciam diferencias de 10 em ordens de magnitude com respeito à máxima probabilidade. Conclusão. A taxa de incidência de RAM e PRM avaliada em diferentes grupos de idade é caracterizada por um comportamento a escala de acordo com a lei de Zipf/Mandelbrot; se encontrou um comportamento não equiprovável da distribuição de relatórios por grupos farmacológicos. Este comportamento poderia evidenciar tendências úteis na vigilância farmacológica.

Chia (Salvia hispanica L.) is a species with seeds that have high essential fatty acid content, which has encouraged increased crop production worldwide. However, the expansion of chia is limited because it is a photoperiod-sensitive plant adapted to areas without cold. The objective of the present study was to determine the effect of different climatic conditions on the growth, grain yield and oil production of chia under irrigation in three geographic areas of Chile: Valle de Azapa (18°30’ S lat) with a coastal desert climate, normal desert climate in Canchones (20°26’ S lat), and Las Cruces (33°30’ S lat) with dry Mediterranean climate with marine influence, and two chia phenotypes: white and dark. Results indicated that desert conditions in the Valle de Azapa (VA) and Canchones (CH) provided better conditions for plant growth; the highest yield (> 2900 kg ha-1) and oil production (> 550 L ha-1). In Las Cruces (LC), at higher latitude, low temperatures present beginning in April coincided with the reproductive stage, affecting yield which was no more than 129 kg ha-1; thus this zone is not recommendable for chia cultivation. This study also determined an 11.8 h day length threshold for the beginning of flowering; when plants are exposed to shorter days flower initiation is more precocious, but when day length is not adequate plants only begin to flower when they have accumulated 600-700 °C d.

Introducción: La teoría de sistemas dinámicos establece medidas cuantitativas de evolución de los sistemas mediante la construcción de atractores. Medidas de ocupación espacial de atractores cardiacos en el espacio fractal de Box Counting diferenciaron normalidad y enfermedad crónica de enfermedad aguda. Objetivo: Aplicar la metodología desarrollada para evaluar matemáticamente el estado cardiaco de Holter con diferentes patologías, confirmando la aplicabilidad de esta metodología para la detección de dinámicas agudas mediante medidas de concordancia estadística respecto al Gold Standard. Metodología: Se analizaron 170 Holter, incluyendo normales, crónicos y en estado agudo. Se construyeron simulaciones de la totalidad de la dinámica basada en número de latidos y frecuencia mínima y máxima cada hora durante 21 horas, para construir atractores en el espacio de fases. Se calculó la dimensión fractal de los atractores evaluando su ocupación espacial en el espacio de Box Counting, estableciendo cuáles corresponden a normalidad y enfermedad aguda de acuerdo con resultados matemáticos previos. Se comparó el diagnóstico matemático con el diagnóstico convencional del Holter, tomado como Gold Standard, estableciendo valores de sensibilidad, especificidad y coeficiente Kappa. Resultados: La dimensión fractal no logró evidenciar diferencias cuantitativas mientras que la metodología detectó en todos los casos dinámicas normales y en estado agudo independientemente de la patología, logrando valores de sensibilidad, especificidad, valor predictivo positivo y negativo de 100%, y coeficiente Kappa de 1. Conclusiones: Se confirmó la capacidad de la metodología físico-matemática para detectar dinámicas agudas independientemente de la patología asociada, confirmando una auto-organización acausal de la dinámica del sistema cuya evaluación permite establecer medidas de aplicabilidad clínica.

Introduction: Dynamic systems theory provides quantitative measures of evolution of systems by building attractors. Spatial occupation measures of cardiac attractors in fractal Box Counting space differentiated normality and chronic disease from acute illness. Objective: To apply the developed methodology to evaluate mathematically the cardiac status of Holter with different pathologies, confirming the applicability of this methodology for the detection of acute dynamic by statistical measures of agreement regarding the Gold Standard. Methodology: 170 Holter, including normal, chronic and in acute states were evaluated. Simulations were constructed the entire dynamic based on the number of beats and the minimum and maximum frequencies every hour for 21 hours, to build attractors in the phase space. The fractal dimension of attractors is calculated, evaluating the spatial occupation in the Box Counting space, establishing which corresponds to normal setting and acute disease in accordance with previous mathematical results. Mathematical diagnosis was compared with conventional diagnostic Holter, taken as the Gold Standard, setting sensitivity, specificity, positive and negative predictive value and Kappa coefficient. Results: The fractal dimension failed to show quantitative differences while the methodology detected in all cases normal dynamics and acute state independently of the disease, achieving sensitivity, specificity, positive and negative predictive value of 100% and a Kappa 1. Conclusions: the ability of the physical-mathematical methodology to detect acute dynamic regardless of the associated pathology was confirmed, as well as an acausal self-organization of the system dynamics, which allows for assessment of clinical applicability measures.

Disease-Related Malnutrition (DRM) is present in a high percentage of patients admitted to hospital and their impact is diverse and of great importance. Objectives: Nutrition Department of University Hospital La Paz, in collaboration with all members of the Nutrition Committee, we decided to implement some method of screening in our centre which allowed us to detect as many patients with malnutrition risk as possible. Results: Due to the large size of our centre, with about 1,500 beds and the few human resources in our unit, we chose to use the CONUT system (Nutritional Control), a 100% automatic method based on analytical parameters, very easy to use, low cost and whose validity is confirmed, characteristics that fulfilled our needs. The method collects information from databases of Admission Service (affiliation, age, date) and Laboratory (albumin, cholesterol, total lymphocytes) and generates, in the report of analytical results, "alert" information about each patient's nutritional risk and also nutritional recommendations based on the risk identified. Prior to its implantation several evaluations were performed in order to allow us to better know the extra workload, as it was the main factor that could limit our ability to assume that screening method and also many training activities for doctors and hospital health professionals who were increasingly assuming responsibilities in the nutritional treatment of their patients. This screening system has been working from june of 2010 and it has detected risk of malnutrition in 32% of the evaluated patients. In general, only in those cases where the alert corresponded to a high-risk nutritional situation, which represents approximately 10% of the total, specialized intervention by the Clinical Nutrition Unit was required. Later, as we have detected some possible causes that justify the system does not work properly; the screening system has undergone several changes . In this sense, we have made a retrospective evaluation of 233 patients admitted to the General Surgery plants and documented that those entering for scheduled surgery, having a alarm of malnutrition (50% of cases), its presence increases significantly the hospital stay and mortality. Conclusions: The implementation of this nutritional screening method has led to a change in the ìnutritionafi culture of our centre respect to DRM in most of our professionals: doctors and nurses and even in the management team, so all of them understand the importance of the process and know about the available tools and knowledge to indicate an adequate and early nutritional support.

La malnutrición asociada a la enfermedad (MAE) está presente en un porcentaje muy elevado de los pacientes que ingresan en los hospitales y su repercusión es diversa y de mucha trascendencia. Objetivo: Desde la Unidad de Nutrición del Hospital Universitario la Paz, en colaboración con todos los miembros de la Comisión de Nutrición, nos planteamos implantar algún método de cribado en nuestro centro, que permitiese abarcar al mayor número posible de pacientes. Resultados: Debido al gran tamaño de nuestro centro, con cerca de 1500 camas, unido a una escasez de recursos humanos en nuestra unidad, optamos por utilizar el sistema de cribado CONUT (Control Nutricional) 100% automático y basado en parámetros analíticos, muy fácil de manejar, de bajo coste y cuya validez está confirmada, adaptándolo a nuestras necesidades. El método recoge información de las bases de datos del servicio de Admisión (filiación, edad, fecha) y del Laboratorio (albúmina, colesterol, linfocitos totales) y genera, en el informe de resultados de los análisis clínicos, la información sobre la alerta de riesgo nutricional de cada paciente, así como las recomendaciones nutricionales a seguir en función del riesgo detectado en cada caso. Para llegar su implantación se llevaron a cabo diferentes evaluaciones que nos permitieron conocer previamente la carga extra de trabajo que podría generar su implantación y nuestra capacidad para asumirlas, así como numerosas actividades formativas encaminadas a que los médicos y profesionales sanitarios del hospital asumieran cada vez más responsabilidades en el proceso del tratamiento nutricional de sus pacientes. Este sistema de cribado funciona desde Junio del año 2010 y detecta riesgo de desnutrición en el 32% de los pacientes evaluados. En general, sólo en los casos en los que la alerta corresponde a una situación de Alto riesgo nutricional, hecho que se da aproximadamente en el 10% del total, se requirió la intervención especializada por parte de la Unidad de Nutrición Clínica y Dietética. Posteriormente, conforme hemos ido detectando posibles causas que justificaran que el sistema no funcionase adecuadamente, el sistema de cribado ha sido objeto de diversas modificaciones. En este sentido, se ha realizado una evaluación retrospectiva en 233 pacientes ingresados en las plantas de Cirugía General y se ha documentado que aquellos que ingresan para cirugía programada y presentan una alarma alta o moderada de desnutrición (el 50% de los casos), la presencia de la misma aumenta significativamente los días de ingreso y la mortalidad. Conclusiones: La implantación del cribado nutricional ha favorecido un cambio en la cultura de nuestro centro con respecto a la malnutrición asociada a la enfermedad y la mayoría de nuestros profesionales, tanto médicos como enfermeras e incluso el equipo directivo, comprenden la importancia del proceso y saben que disponemos de herramientas y de conocimiento suficiente para indicar un soporte nutricional adecuado y precoz.

After three cases of legionellosis associated with a spa were identified, an investigation was conducted to confirm the source of infection, determine the risk factors, and establish control measures. Between November 26, 2008 and September 16, 2009, six inspections were carried out, samples were collected for Legionella pneumophila isolation, and water temperature was determined at all the sampling points of the hot water system and at the spa pools. The presence of L. pneumophila serogroup 1 with the same molecular pattern as that found in the clinical isolate was confirmed in the hot water system (with a low proliferation risk according to legislation). The crude attack rate was 0.34% (95% CI: 0.09-0.94). Samples without L. pneumophila were obtained only after structural changes were carried out. Possible factors participating in the cluster were water temperatures between 25ºC and 30ºC, stagnant water and early morning exposure.

Ante tres casos de legionelosis asociados a un establecimiento balneario se inició la investigación para confirmar la fuente de infección, determinar el riesgo y controlarlo. Entre el 26 de noviembre de 2008 y el 16 de septiembre de 2009 se realizaron seis inspecciones, con toma de temperaturas y muestras de agua para el aislamiento de Legionella pneumophila en todos los puntos de la red de agua caliente sanitaria y en las piscinas climatizadas. Se confirmó la presencia de L. pneumophila del serogrupo 1 con el mismo patrón molecular que la cepa clínica en el circuito de agua caliente sanitaria (de bajo riesgo de proliferación). La tasa de ataque bruta fue del 0,34% (intervalo de confianza del 95%: 0,09-0,94). Solo se obtuvieron muestras de agua sin presencia de L. pneumophila tras realizar cambios estructurales. Las temperaturas del agua entre 25 y 30ºC, el estancamiento del agua y la exposición a primera hora de la mañana serían factores participantes en la agrupación de casos.

After three cases of legionellosis associated with a spa were identified, an investigation was conducted to confirm the source of infection, determine the risk factors, and establish control measures. Between November 26, 2008 and September 16, 2009, six inspections were carried out, samples were collected for Legionella pneumophila isolation, and water temperature was determined at all the sampling points of the hot water system and at the spa pools. The presence of L. pneumophila serogroup 1 with the same molecular pattern as that found in the clinical isolate was confirmed in the hot water system (with a low proliferation risk according to legislation). The crude attack rate was 0.34% (95% CI: 0.09-0.94). Samples without L. pneumophila were obtained only after structural changes were carried out. Possible factors participating in the cluster were water temperatures between 25ºC and 30ºC, stagnant water and early morning exposure.

Ante tres casos de legionelosis asociados a un establecimiento balneario se inició la investigación para confirmar la fuente de infección, determinar el riesgo y controlarlo. Entre el 26 de noviembre de 2008 y el 16 de septiembre de 2009 se realizaron seis inspecciones, con toma de temperaturas y muestras de agua para el aislamiento de Legionella pneumophila en todos los puntos de la red de agua caliente sanitaria y en las piscinas climatizadas. Se confirmó la presencia de L. pneumophila del serogrupo 1 con el mismo patrón molecular que la cepa clínica en el circuito de agua caliente sanitaria (de bajo riesgo de proliferación). La tasa de ataque bruta fue del 0,34% (intervalo de confianza del 95%: 0,09-0,94). Solo se obtuvieron muestras de agua sin presencia de L. pneumophila tras realizar cambios estructurales. Las temperaturas del agua entre 25 y 30ºC, el estancamiento del agua y la exposición a primera hora de la mañana serían factores participantes en la agrupación de casos.