Background: Neurocysticercosis is the most prevalent parasitic disease of the central nervous system in Chile, where sporadic cases are reported, without information about the epidemiology or distribution of the disease. Aim: To identify the main risk zones for cysticercosis in Chile. Material and Methods: Analysis of hospital discharge databases between 2002 and 2019, available at the website of the Chilean Ministry of Health. Cases with B69 code of the tenth international classification of diseases were identified. Results: In the study period, there were 1752 discharges with the diagnoses of neurocysticercosis, ocular cysticercosis and cysticercosis of other sites. The ages of patients ranged from 0 to 89 years with a clustering between 30 and 59 years. Sixty two percent were males. The zone between the regions of Maule and Araucania concentrated 82% of cases. Conclusions: We identified the zone with the greatest concentration of cysticercosis in Chile, where preventive strategies should eventually be directed.

Resumo: Os métodos de geocodificação automática se tornaram populares nos últimos anos para facilitar o estudo da associação entre desfechos de saúde e lugar de residência. Entretanto, poucos estudos avaliaram a qualidade da geocodificação, e a maioria dos estudos existentes foi realizada nos Estados Unidos e Europa. O estudo teve como objetivo comparar a qualidade de três ferramentas de geocodificação eletrônica automática em relação a um método de referência. Foi geocodificada uma subamostra de 300 endereços anotados à mão em prontuários hospitalares, usando Bing, Google Earth e Google Maps. As taxas de correspondência dos registros foram mais altas (> 80%) com Google Maps e Google Earth, comparado com Bing. Entretanto, a acurácia dos endereços foi melhor com Bing, com uma proporção maior (> 70%) de endereços com erros de localização menores que 20 metros. Em geral, o desempeno não variou para cada método de acordo com condição socioeconômica. Os métodos apresentaram desempenho geral aceitável, porém heterogêneo. Os resultados servem de alerta contra o uso de métodos automáticos sem avaliar a qualidade em outras cidades, particularmente no Chile e no resto da América Latina.

Abstract: Automatic geocoding methods have become popular in recent years, facilitating the study of the association between health outcomes and the place of living. However, rather few studies have evaluated geocoding quality, with most of them being performed in the US and Europe. This article aims to compare the quality of three automatic online geocoding tools against a reference method. A subsample of 300 handwritten addresses from hospital records was geocoded using Bing, Google Earth, and Google Maps. Match rates were higher (> 80%) for Google Maps and Google Earth compared with Bing. However, the accuracy of the addresses was better for Bing with a larger proportion (> 70%) of addresses with positional errors below 20m. Generally, performance did not vary for each method for different socioeconomic status. Overall, the methods showed an acceptable, but heterogeneous performance, which may be a warning against the use of automatic methods without assessing quality in other municipalities, particularly in Chile and Latin America.

Resumen: Los métodos automáticos de geocodificación se han convertido en algo popular durante los últimos años para facilitar el estudio de la asociación entre resultados de salud y lugar para vivir. No obstante, más bien pocos estudios han evaluado la calidad de la geocodificación, siendo realizados la mayoría de ellos en EE.UU. y Europa. El objetivo de este artículo es comparar la calidad de tres herramientas automáticas de geocodificación en línea frente a un método de referencia. La submuestra de 300 direcciones escritas a mano, procedentes del registro hospitalario, se geocodificaron usando Bing, Google Earth y Google Maps. Los porcentajes de coincidencia fueron mayores (> 80%) en el caso de Google Maps y Google Earth comparados con Bing. Sin embargo, la precisión de las direcciones fue mejor con Bing, en una proporción más grande (> 70%) de direcciones que tenían errores de posición por debajo de 20m. En general, el rendimiento no varió en cada método para diferentes niveles estatus socioeconómico. En general, los métodos mostraron un rendimiento aceptable, pero heterogéneo. Esto previene contra el uso de métodos automáticos sin evaluar la calidad en otras ciudades, particularmente en Chile y Latinoamérica.

Resumo: Os métodos de geocodificação automática se tornaram populares nos últimos anos para facilitar o estudo da associação entre desfechos de saúde e lugar de residência. Entretanto, poucos estudos avaliaram a qualidade da geocodificação, e a maioria dos estudos existentes foi realizada nos Estados Unidos e Europa. O estudo teve como objetivo comparar a qualidade de três ferramentas de geocodificação eletrônica automática em relação a um método de referência. Foi geocodificada uma subamostra de 300 endereços anotados à mão em prontuários hospitalares, usando Bing, Google Earth e Google Maps. As taxas de correspondência dos registros foram mais altas (> 80%) com Google Maps e Google Earth, comparado com Bing. Entretanto, a acurácia dos endereços foi melhor com Bing, com uma proporção maior (> 70%) de endereços com erros de localização menores que 20 metros. Em geral, o desempeno não variou para cada método de acordo com condição socioeconômica. Os métodos apresentaram desempenho geral aceitável, porém heterogêneo. Os resultados servem de alerta contra o uso de métodos automáticos sem avaliar a qualidade em outras cidades, particularmente no Chile e no resto da América Latina.

Abstract: Automatic geocoding methods have become popular in recent years, facilitating the study of the association between health outcomes and the place of living. However, rather few studies have evaluated geocoding quality, with most of them being performed in the US and Europe. This article aims to compare the quality of three automatic online geocoding tools against a reference method. A subsample of 300 handwritten addresses from hospital records was geocoded using Bing, Google Earth, and Google Maps. Match rates were higher (> 80%) for Google Maps and Google Earth compared with Bing. However, the accuracy of the addresses was better for Bing with a larger proportion (> 70%) of addresses with positional errors below 20m. Generally, performance did not vary for each method for different socioeconomic status. Overall, the methods showed an acceptable, but heterogeneous performance, which may be a warning against the use of automatic methods without assessing quality in other municipalities, particularly in Chile and Latin America.

Resumen: Los métodos automáticos de geocodificación se han convertido en algo popular durante los últimos años para facilitar el estudio de la asociación entre resultados de salud y lugar para vivir. No obstante, más bien pocos estudios han evaluado la calidad de la geocodificación, siendo realizados la mayoría de ellos en EE.UU. y Europa. El objetivo de este artículo es comparar la calidad de tres herramientas automáticas de geocodificación en línea frente a un método de referencia. La submuestra de 300 direcciones escritas a mano, procedentes del registro hospitalario, se geocodificaron usando Bing, Google Earth y Google Maps. Los porcentajes de coincidencia fueron mayores (> 80%) en el caso de Google Maps y Google Earth comparados con Bing. Sin embargo, la precisión de las direcciones fue mejor con Bing, en una proporción más grande (> 70%) de direcciones que tenían errores de posición por debajo de 20m. En general, el rendimiento no varió en cada método para diferentes niveles estatus socioeconómico. En general, los métodos mostraron un rendimiento aceptable, pero heterogéneo. Esto previene contra el uso de métodos automáticos sin evaluar la calidad en otras ciudades, particularmente en Chile y Latinoamérica.

Abstract Background: In Chile, cystic echinococcosis is endemic throughout the country and hyperendemic in some regions such as La Araucanía and Aysén and continues to be a neglected public health problem. Aim: To estímate the risk of human hydatidosis in Aysén, studying the relationship of notifications and hospital discharge rates with social and environmental factors, such as population, multidimensional poverty index, urbanization, average temperature, average rainfall and sheep population. Methods: Poisson regressions were used to study the factors associated with notifiable diseases and hospital discharge rates and the Besag-York-Mollie model for relative risk. Results and Conclusions: Aysén has a high risk, between 2 and 19 times that expected for the region. A significant underreporting of cases was found. The model of hospital discharges had a good fit showing the positive influence of the human and bovine population and the positive effect of temperature. An effect of the multidimensional poverty index was also detected, which is mainly affected by education and working conditions. Excepting one locality, the areas of greatest risk correspond to the eastern cordon of the Aysén region.

Resumen Introducción: En Chile, la equinococosis quística o hidatidosis es endémica a lo largo de todo el país e hiperendémica en algunas regiones como La Araucanía y Aysén y sigue siendo un problema de salud pública desatendido. Objetivo: Estimar el riesgo de hidatidosis humana en Aysén, estudiando la relación de las notificaciones y egresos con factores sociales y ambientales, tales como población, índice de pobreza multidimensional, urbanización, temperatura media, precipitación media y población ganadera ovina. Metodología: Se utilizaron regresiones de Poisson para estudiar los factores asociados a enfermedades de notificación obligatoria y egresos y el modelo Besag-York-Mollie para el riesgo relativo. Resultados y Conclusiones: Aysén tiene un alto riesgo de hidatidosis humana, entre 2 y 19 veces el esperado para la región. Se encontró una importante sub-notificación de casos. El modelo de los egresos hospitalarios tuvo un buen ajuste mostrando la influencia positiva de la población humana y ovina y el efecto positivo de la temperatura. También se detectó un efecto del índice de pobreza multidimensional sobre los casos y egresos hospitalarios, que es principalmente afectado por la educación y de condiciones de trabajo. Exceptuando la comuna de O’Higgins, las zonas de mayor riesgo corresponden al cordón oriental de la Región de Aysén.

Background: In Chile, hydatidosis is endemic throughout the country and hyperendemic in some regions. It continues to be a public health problem that has been neglected and little addressed at the national level. In the Region of Libertador Bernardo O’Higgins, reported cases and hospital discharges still show high values, this area being representative of medium risk. Aim: To estimate the risk of human hydatidosis in this region, studying the relationship of notifications and hospital discharge rates with social and environmental factors such as population, poverty index, schooling, literacy, average temperature, average rainfall and sheep population size. Methods: Poisson regressions were used to study the factors associated with reported cases and hospital discharge rates and the BYM model for relative risk. Results: We found that the factors most related to absolute risk were the schooling index as a protective factor and the average temperatures as an enhancing factor. The sheep population size was also a relevant factor, especially when analyzing the distribution of relative risk. The areas of greatest risk in the region were La Estrella, Marchigue, Litueche, Santa Cruz and Lolol according to discharge rates, adding Pumanque and Peralillo according to notifications. These reveal a distribution of the zones of risk of hydatidosis towards the coastal mountain range in this region. Discussion/Conclusion. The more relevant factors associated to hydatidosis were schooling index, temperature an sheep population.

Resumen Introducción: En Chile, la hidatidosis, endémica a lo largo de todo el país e hiperendémica en algunas regiones, sigue siendo un problema de salud pública desatendido y poco abordado por el Estado. En la Región del Libertador Bernardo O’Higgins, los casos reportados y los egresos hospitalarios aún muestran valores elevados, siendo esta zona representativa de riesgo medio. Objetivo: Estimar el riesgo de hidatidosis humana en esta región, estudiando la relación de las notificaciones y egresos con factores sociales y ambientales, tales como población, índice de pobreza, índice de escolaridad, alfabetización, temperatura media, precipitación media y masa ganadera ovina. Metodología: Se utilizaron regresiones de Poisson para estudiar los factores asociados a enfermedades de notificación obligatoria y egresos y el modelo Besag-York-Mollie para el riesgo relativo. Resultados: Los factores más relacionados con el riesgo absoluto fueron el índice de escolaridad como factor protector y las temperaturas medias como factor potenciador. La población ovina fue también un factor relevante especialmente al analizar la distribución del riesgo relativo. Las zonas de mayor riesgo en la región fueron La Estrella, Marchigüe, Litueche, Santa Cruz y Lolol según egresos, agregando a Pumanque y Peralillo según notificaciones. Éstas revelan una distribución de las zonas de riesgo de hidatidosis hacia la cordillera de la costa en esta región. Conclusiones: En esta región los principales predictores de riesgo de hidatidosis son el índice de escolaridad, la temperatura y la población ovina.

Background: Zoonoses are infections caused by all types of etiological transmissible agents from vertebrate animals to humans. During the last decades, the risk to health caused by different zoonoses has been a consequence of the natural distribution of the different etiological agents and by the emergence and reemergence of these diseases. Aim: To study the distribution of the risk of mortality of the four main zoonoses in continental Chile, based on national mortality data, with the objective of visualizing geographically where to focus the control efforts of these diseases. Methods: Relative risk was estimated by means of Bayesian Statistics. Results: The distribution in Chile of the main zoonoses was obtained. Discussion/Conclusion: The risk maps obtained show a parasitic disease transmitted by high-risk vectors in the north, Chagas disease; a parasitic disease of biological communities in which man is an accidental host, associated with livestock areas, more prevalent in the south, hydatidosis; a bacterial disease transmitted by vertebrates, especially by rodents, where water is an important vehicle, dominant in the center, leptospirosis; and a viral disease transmitted by rodents, very dominant in the south, the hantavirus infection.

Resumen Introducción: Las zoonosis son enfermedades o infecciones causadas por todo tipo de agentes etiológicos transmisibles desde animales vertebrados a humanos. Durante las últimas décadas, el riesgo para la salud ocasionado por diferentes zoonosis, ha sido generado por la distribución natural de los distintos agentes etiológicos y por la emergencia y reemergencia de estas enfermedades. Objetivo: Estudiar la distribución del riesgo de mortalidad de las cuatro principales zoonosis en Chile continental, basados en datos nacionales de mortalidad, con el objetivo de visualizar geográficamente donde focalizar los esfuerzos de control de estas enfermedades. Metodología: Se estima el riesgo relativo de las principales zoonosis en Chile, mediante estadística Bayesiana. Resultados: Se obtuvo la distribución de las cuatro principales zoonosis de Chile. Discusión/Conclusión: Se obtuvo la distribución de las cuatro principales zoonosis de Chile. Los mapas de riesgo obtenidos muestran una enfermedad parasitaria transmitida por vectores de alto riesgo en el norte, la enfermedad de Chagas; una enfermedad parasitaria de comunidades biológicas en que el hombre es un hospedero accidental, asociada a zonas ganaderas, prevalente en el sur, la hidatidosis; una enfermedad bacteriana transmitida por vertebrados, especialmente por roedores, donde el agua es un vehículo importante, dominante en el centro, la leptospirosis; y una enfermedad viral transmitida por roedores, muy dominante en el sur, la infección por hantavirus.

Background: Reproductive number (R0)-maps estimate risk zones of vector-borne diseases and geographical distribution changes under climate change. Aim: To map R0 aiming to estimate the epidemiological risk of Chagas disease in Chile, its distribution and possible changes due to the global climate change. Material and Methods: We used a relationship between R0 and entomological parameters of vectors as function of environmental variables, to map the risk of Chagas disease in Chile, under current and projected future environmental conditions. Results: We obtained a geographical R0 estimation of Chagas disease in Chile. The highest R0averages correspond to the Central-Northern regions of Chile. T. cruzi transmission area could increase in the future due to climate changes. Independent of the future condition, both for optimistic and pessimistic climate change scenarios, the area of potential risk for Chagas disease transmission would increase. The estimated R0 values suggest that, if a control of T. infestans is not maintained, Chagas disease endemic status will persist or increase, independently of the climate change scenarios. Conclusions: Mapping R0 values is an effective method to assess the risk of Chagas disease. The eventual increase in the transmission area of the disease is worrisome.

SUMMARY The frequency of anti-Toxocara spp. antibodies in individuals attended by the Centro de Salud Familiar in the coastal Niebla town, Chile, was related to the host and to environmental factors. IgG anti- Toxocara antibodies were detected with a commercial ELISA kit (SCIMEDX Corporation, USA). Samples with undetermined absorbance values were subjected to an additional ELISA standardized by the Instituto de Salud Pública, Chilean Health Ministry, a commercial ELISA (NOVATEC, Germany), and a commercial Western blot kit (LDBio Diagnostics, France). Hematological exams were performed using an automated blood counter and blood smears. Dog feces were collected from the ground along the main road in Niebla, including rural and urban locations. Ninety (25.4%) of the 355 examined individuals were positive by the ELISA test. The frequency of anti-Toxocara antibodies and the infection risk were significantly higher (p < 0.05) among those individuals ≥ 40 years old with respect to the 20-39 years old group, in individuals from rural locations, those who did not have a safe drinking water supply in the house or who presented blood eosinophilia. The proportion of positive samples of dog feces and the mean number of Toxocara canis eggs/g of feces in urban and rural areas were similar (p > 0.05).

In this paper, an analysis on the main technical features of digital television standards for satellite transmission is carried out. Based on simulations and link budgets, the standard with the best operational performance is defined, based on simulations and link budget analysis, as well as a comparative efficiency analysis is conducted for the Ku and Ka bands for both transparent and regenerative transponders in terms of power, bandwidth, information rate and link margin, including clear sky, uplink rain, downlink rain and rain in both.

En este artículo se lleva a cabo un análisis de las principales características técnicas de los estándares para la transmisión de televisión digital por satélite. Con base en simulaciones y cálculo de enlaces se determina el estándar con mejor desempeño operativo y se realiza una comparación de la eficiencia para transmisiones en las bandas Ku y Ka con transpondedores transparentes y regenerativos, en términos de potencia, ancho de banda, tasa de información y margen del enlace, tanto a cielo despejado, como con lluvia en el enlace ascendente, en el descendente y en ambos.