RESUMO
Chagas continues to be a relevant public health problem in Latin America. In this work, we present a spatiotemporal analysis applied for the evaluation and planning of Chagas vector control strategies. We analysed the spatial distribution of the vector Triatoma infestans infestation related to ongoing control interventions cycles in rural communities near Añatuya, Santiago del Estero, Argentina. A geographical information system was developed for the spatial analysis obtaining, for each house, variables that describe the history of spraying and infestation at each time of interventions. Bi-dimensional histograms were used to describe the spatiotemporal pattern of these activities and peri-domestic infestation at the last intervention was modelled by a neural network model. We qualitatively evaluate control programmes considering the history of infestation and spraying from a spatiotemporal point of view, incorporating new ways of visualising this information. Predictions are based on novel, non-linear models and spatiotemporal indices, which should be useful for strategically allocating Chagas control resources in the future and thus help to better plan spraying strategies.
Assuntos
Doença de Chagas/epidemiologia , Doença de Chagas/prevenção & controle , Controle de Insetos/estatística & dados numéricos , Insetos Vetores , Análise Espaço-Temporal , Triatoma , Animais , Argentina/epidemiologia , Sistemas de Informação Geográfica , Humanos , Controle de Insetos/métodos , Inseticidas/administração & dosagem , População RuralRESUMO
Vector control of Chagas disease in the past decades has been mainly based on chemical control. Fundación Mundo Sano is implementing an Integral Chagas Program in a rural area of the Argentinean Gran Chaco Region since 2002. The objective of this study was to analyze both, temporal and spatial variation of infestation indices and their relation to the actions of the Program and environmental variables as land and vegetation cover changes, during a 5 year intervention period (2010-2014). Triatoma infestans infestation data from five rural localities from the Province of Santiago del Estero (Argentina) was analyzed in order to detect spatial aggregation. Differences in control effectiveness were observed between the peridomicile and intradomicile: infestation indices were higher in the peridomicile, recurrent infestation was present only in the peridomicile while low level infestation clusters were absent in the peridomicile. Cluster zones with low intradomestic infestation had larger proportions of bare soil and thin vegetation. In contrast, cluster zones with high intradomestic infestation had higher forest vegetation proportions and smaller cultivated area proportions. Spatial statistics analysis detected differences in cluster patterns between intra and peridomestic infestation suggesting that control actions should be based on geographical areas and not on political units. This work brings together different approaches to analyze infestation levels at the fine spatial scale, which could be used as a base for risk spatial stratification.
Assuntos
Doença de Chagas/transmissão , Controle de Insetos/métodos , Triatoma , Animais , Meio Ambiente , Humanos , Insetos VetoresRESUMO
INTRODUCCIÓN Los desastres naturales de origen atmosférico, geológico ó hídrico son eventos catastróficos que provocan consecuencias en el ámbito de la salud, con fuertes impactos económicos y sociales. El impacto sobre el bienestar de la población expuesta no sólo está dado por habitar zonas afectadas por las inundaciones, sino también por los modos de vida y sus condicionantes. El concepto de riesgo posibilita seleccionar algunos factores que permiten generar intervenciones/recomendaciones, a través de acciones puntuales y específicas con aspectos bioecológicos y socioculturales. OBJETIVO Elaborar, evaluar y validar una herramienta dinámica que permita planificar e implementar acciones oportunas de prevención y mitigación de daños para la salud, ante la potencial ocurrencia de inundaciones o precipitaciones mayores a la media histórica estacional. MÉTODOS El estudio, analítico y de diseño transversal, incluye los departamentos de la cuenca del Plata por ser esta la cuenca del país más afectada por eventos de inundaciones. Se identificaron las posibles enfermedades que pudiesen ocurrir durante y después de una inundación; leptospirosis, dengue-chikungunya-zika, picadura de animales ponzoñosos, diarrea, hepatitis, y enfermedades respiratorias agudas. Se determinaron variables sociodemográficas, económicas y ambientales, relacionadas con procesos de salud-enfermedad-atención y cuidado, así como la respuesta social organizada para cada uno de los seis eventos. Posteriormente se hizo una selección de expertos para cada enfermedad quienes, utilizando el método propuesto por Saaty ponderaron los factores de amenazas y vulnerabilidad (determinantes del riesgo). RESULTADOS El riesgo de ocurrencia de diarreas en población de un departamento, de acuerdo con los expertos, está asociado con el porcentaje de área inundada; las condiciones en las que vive la población, la falta de accesibilidad y disponibilidad de agua segura, la falta de desagüe cloacal a red pública, condiciones de hacinamiento, la densidad poblacional y las limitaciones de acceso a los servicios de salud. DISCUSIÓN En relación a las fuentes de información, tanto su representatividad (en este caso, fuentes secundarias) como su temporalidad (ej. censo 2010) pueden ser mejoradas y actualizadas cuando estén disponibles para mejorar las precisiones de esta herramienta. Se entiende que dichas limitaciones podrían impactar directamente sobre las decisiones concretas para planificar e implementar acciones oportunas de prevención y mitigación de daños para la salud priorizando o no adecuadamente un departamento por sobre otro, por lo que se ve la necesidad de seguir revisando todo el procedimiento de ejecución de la presente metodología
Assuntos
Vulnerabilidade a Desastres , Planejamento em Desastres , Indicador de Risco , Risco Natural , Ameaças NaturaisRESUMO
Based on an agreement between the Ministry of Health and the National Space Activities Commission in Argentina, an integrated informatics platform for dengue risk using geospatial technology for the surveillance and prediction of risk areas for dengue fever has been designed. The task was focused on developing stratification based on environmental (historical and current), viral, social and entomological situation for >3,000 cities as part of a system. The platform, developed with open-source software with pattern design, following the European Space Agency standards for space informatics, delivers two products: a national risk map consisting of point vectors for each city/town/locality and an approximate 50 m resolution urban risk map modelling the risk inside selected high-risk cities. The operative system, architecture and tools used in the development are described, including a detailed list of end users' requirements. Additionally, an algorithm based on bibliography and landscape epidemiology concepts is presented and discussed. The system, in operation since September 2011, is capable of continuously improving the algorithms producing improved risk stratifications without a complete set of inputs. The platform was specifically developed for surveillance of dengue fever as this disease has reemerged in Argentina but the aim is to widen the scope to include also other relevant vector-borne diseases such as chagas, malaria and leishmaniasis as well as other countries belonging to south region of Latin America.