Spatial Distribution of Aedes aegypti Oviposition Temporal Patterns and Their Relationship with Environment and Dengue Incidence

Aedes aegypti, the mosquito species transmitting dengue, zika, chikungunya and yellow fever viruses, is fully adapted to thrive in urban areas. The temporal activity of this mosquito, however, varies within urban areas which might imply different transmission risk. In this work, we hypothesize that temporal differences in mosquito activity patterns are determined by local environmental conditions. Hence, we explore the existence of groups of temporal patterns in weekly time series of Ae. aegypti ovitraps records (2017–2019) by means of time series clustering. Next, with the aim of predicting risk in places with no mosquito field data, we use machine learning classification tools to assess the association of temporal patterns with environmental variables derived from satellite imagery and predict temporal patterns over the city area to finally test the relationship with dengue incidence. We found three groups of temporal patterns that showed association with land cover diversity, variability in vegetation and humidity and, heterogeneity measured by texture indices estimated over buffer areas surrounding ovitraps. Dengue incidence on a neighborhood basis showed a weak but positive association with the percentage of pixels belonging to only one of the temporal patterns detected. The understanding of the spatial distribution of temporal patterns and their environmental determinants might then become highly relevant to guide the allocation of prevention and potential interventions. Further investigation is still needed though to incorporate other determinants not considered here.Fil: Andreo, Verónica Carolina. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Porcasi Gomez, Ximena. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Guzmán, Claudio Daniel. Provincia de Córdoba. Ministerio de Salud; ArgentinaFil: López, Laura. Provincia de Córdoba. Ministerio de Salud; ArgentinaFil: Scavuzzo, Carlos Matias. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Intestinal parasitic infections in a community from Pampa del Indio, Chaco (Argentina) and their association with socioeconomic and environmental factors

Neglected tropical diseases are a group of 20 disabling diseases, which, in particular, are the most common chronic infections in the most vulnerable people. This study aimed to characterize the infection by intestinal parasites (IPs) in dwellings from a peri-urban neighborhood in Pampa del Indio, Chaco (Argentina), and its association with socioeconomic and environmental variables. Single stool samples were collected from all individuals older than 1 year through household visits and processed using coprological sedimentation and flotation techniques. Standardized questionnaires were used at the household level to collect socio-economic information. Environmental variables were obtained from the Planetscope image, Landsat 8 images and remote sensors, while land-use layers were obtained through the use of a maximum likelihood algorithm. Stool samples were provided by 314 individuals. The prevalence of IPs found was 30.6% (n = 96), with a predominance of Giardia lamblia (12.7%, n = 40) and Hymenolepis nana (7.6%, n = 24). The only soil-transmitted helminth found was Strongyloides stercoralis with a 2.5% prevalence (n = 8). Individuals of adult age (> 18 years) were 0.65 times less likely to present parasitic infections with respect to children and adolescents. The only environmental variable that was closely associated with the presence of IPs, was the Normalized Difference Water Index (NDWI), a measure of humidity; being higher around houses with positive individuals. Most of the IPs found in this study were of water-borne transmission and those transmitted directly from person-to-person, therefore fecal contamination is present. We believe that the low prevalence of STH in this area, which requires a passage through the soil, is related to the environmental characteristics, which are unsuitable for the development/permanence of the infective stages of these parasites. The geospatial data and tools used herein proved to be useful for the study of the relationship between the different factors that influence the presence of IPs in a community, from an eco-health approach.Fil: Scavuzzo, Carlos Matias. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; Argentina. Fundación Mundo Sano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delgado, Cintia. Fundación Mundo Sano; ArgentinaFil: Goy, Marcia. Hospital Dr. Dante Tardelli; ArgentinaFil: Crudo, Favio. Fundación Mundo Sano; ArgentinaFil: Porcasi, Ximena. Comision Nacional de Actividades Espaciales. Instituto de Altos Estudios Espaciales "Mario Gulich"; ArgentinaFil: Periago, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Mundo Sano; Argentin

Geomática aplicada a un sistema de alerta temprana

En el presente trabajo se plantea una Infraestructura Informática para dar soporte a la prevención y el control estratégico del vector del dengue en Argentina por parte del Ministerio de Salud de la Nación. La misma es parte de un complejo Sistema de Alerta Temprana (SAT) y es llevado a cabo por la Comisión Nacional de Actividades Espaciales (CONAE) bajo los estándares de la European Spatial Agency (ESA). La arquitectura, diseño, metodología y codificación pretenden ser componentes re-utilizables en cualquier infraestructura informática de soporte a SATs. En su desarrollo se utiliza Open Source Software (OSS) y Patrones de Diseño (Design Patterns) garantizando una herramienta tecnológica además de re-utilizable, flexible, mantenible y robusta. En este documento se describen los requerimientos establecidos por el Ministerio de Salud de la Nación y se plantea la arquitectura y diseño del sistema a partir de los mismos. Además, se realiza un análisis de las tecnologías OSS integradas en el desarrollo y la codificación. Finalmente se describe la funcionalidad obtenida y se muestra la infraestructura con un caso en particular.Sociedad Argentina de Informática e Investigación Operativ

Algoritmos para el alerta temprana de dengue en un ambiente geomático

En el marco de un convenio CONAE-Ministerio de Salud de la Nación se está desarrollando un proyecto para implementar un sistema informático de Alerta Temprana de Dengue. Mientras que el sistema y sus subsistemas son descriptos brevemente, en este trabajo se explica detalladamente la unidad Environmental Risk del subsistema Algorithm Executor encargada del proceso que calcula el riesgo ambiental de Dengue a nivel de localidades de la República Argentina. El cálculo de riesgo implica la suma de dos componentes: a) una estática relacionada con las condiciones ambientales históricas que determinan la probabilidad de que el vector se desarrolle en el lugar y b) una componente dinámica relacionada con las condiciones actuales que posibiliten la transmisión viral. La primera componente se estima mediante una combinación de los métodos de Máxima Entropía y de Regresión Logística, mientras que la segunda componente es calculada por un algoritmo que contabiliza la cantidad de períodos de incubación extrínseca que pueden ser completados en cada localidad de acuerdo a la temperatura media diaria, estimada desde un satélite. Se muestra como resultado la estratificación de las localidades de Argentina en función de su riesgo ambiental de Dengue.Sociedad Argentina de Informática e Investigación Operativ

Regional scale environmental variables complementing a Risk Model of Chagas Disease vectorial transmission

In thIS study we present advances in the analysis of environmental variables obtained from moderate resolution satellite images and their association with infestation indexes by Triatoma infestans (vector of Chagas disease). The environmental variables considered are the result of climatology and anomalY summaries derived from MODIS sensor time series (products MOD11A2 and MOD13A2) for the period 2000 to 2015), land use from Serena and precipitation from TRMM. The infestation, which was measured at the locality / rural LOCATION level, is expressed as a percentage of households with presence of T. infestans. Data was collected from the National Chagas service. Generalized linear models are proposed to associate the infestation with the environmental variables OBTAINED FROM SATELLITE IMAGES and other local conditions (characteristics of the dwellings and the presence of domestic animals). In general, the environmental variables considered in the models have more influence on Infestation indexes than the locals variables. The variables with the best adjustment were: annual average of LST of the years 2013 and 2015, the NDVI of 2014 and the anomalies of NDVI of the same year. These variables showed higher weights than the variables representing local conditions. From an eco-epidemiological perspective, the usage of products derived from sensors with Medium resolution with national coverage are tools which allow decision makers to generate more accurate responses in less time

El paisaje y su interacción con actividades de control de la enfermedad de Chagas en áreas rurales de Argentina

Chagas Diseases affects millions of persons with low resources mainly in rural environments. This works was based in landscape ecology concept where human and ecologic processes interact with the landscape. We relate vegetation cover and bare soil patterns with infestation of Triatoma infestans main vector of Chagas Disease) in arid Chaco. Classification of Landsat TM images were used to obtain landscape metrics over little localities in rural areas.. as results we observed an spatial tendency in east west sense, where the bare soil patches were bigger and the edge complexity higher (correlation with X axis R=0.73 and R=0.75, respectively). The landscape measures allowed the discrimination of localities from low and high infestation levels (identified previously by point spatial analysis) with an efficiency of 98 % (Wilks-lambda=0.166 F(8,47)=29.463, p<0.01). The localities with more infestation had more fragmented vegetation and more proportion of bare soil. The environmental degradation constrains the socio-economical condition of inhabitants in the area, where subsistence farming is the main economic activity in the area. These results remark the need to address the control of neglected disease in a global approach.Pages: 8381-838

A LANDSCAPE ECOLOGY APPROACH FOR A NEGLECTED DISEASE IN RURAL AREAS OF ARGENTINA

In recent years, there have been problems in controlling the population of the main vector of Chagas disease, Triatoma infestans in the Great Chaco region over Paraguay and Argentina. This study was carried out in an area of the Chaco region, La Rioja province (Los Llanos), where almost 50% of the houses in the region have dirt floors, no tap water and/or sanitary infrastructure. The main economic activity on these rural areas is goat breeding where corrals provides one of the best refuges for T. infestans. The study aimed to analyze the reciprocal effects between spatial patterns and ecological-human processes in the Los Llanos region. We propose that the landscape patterns can be measured and quantified through satellite images and that this characterization could be used to analyze a possible association between the presence of stockbreeding structures and the peridomestic infestation patterns found in the study area. On the basis of the correlations identified, it would be possible to indirectly relate the vegetation covering with the life quality of the rural inhabitants of Los Llanos region

Development of a geographical distribution model of Rhodnius pallescens Barber, 1932 using environmental data recorded by remote sensing

Rhodnius pallescens, main vector of Trypanosoma cruzi in Panama and secondary vector in Colombia, Costa Rica and Nicaragua, represents an important epidemiological risk in those countries. It occupies sylvatic ecotopes, and because of this its distribution and abundance could be conditioned by environmental factors. In this work, we integrated environmental variables recorded by remote sensing and data of R. pallescens presence in the countries mentioned above in order to know the environmental variables with better capacity to describe the insects' distribution, which will help to entomological surveillance and control. Standard discriminant analysis (DA) was used to determine if there is a significant difference in the environmental variation between the presence and the absence sites of R. pallescens. Forward stepwise discriminant analysis (fDA) was used to determine the environmental variables which better discriminated between presence and absence sites, and to construct a predictive map of geographical distribution. Univariate analyses were used to determine the discriminatory power of individual variables. The model derived from DA showed 89% of sensitivity and 92.8% of specificity. Multivariate and univariate analyses showed the vapor pressure deficit minimum as the principal variable among the nine most important to describe the distribution of the species, which is in agreement with the R. pallescens stenohydric status. Map shows insects' distribution predicted by environmental variables, and moreover includes the distribution of most species belonging to Rhodnius genus, except R. domesticus, R. nasutus and R. neglectus. We interpreted these results as a reflection of the common evolution of the most Rhodnius species, except for the last ones that probably evolved isolated due to particular environmental conditions. In conclusion, this study showed that a reduced number of environmental variables can predict the distribution of R. pallescens and related species. This methodology can be very useful to make critical decisions for vectorial surveillance and control of Chagas disease vectors.Fil: Arboleda, Sair. Universidad de Antioquia; ColombiaFil: Gorla, David Eladio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Porcasi Gomez, Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Saldaña, Azael. Instituto Conmemorativo Gorgas de Estudios de la Salud; PanamáFil: Calzada, Jose. Instituto Conmemorativo Gorgas de Estudios de la Salud; PanamáFil: Jaramillo, Nicolas. Universidad de Antioquia; Colombi