Hotspots and correlates of soil-transmitted helminth infections in a Venezuelan rural community: Which are the "wormy" houses?

OBJECTIVES: To determine spatial clustering and risk factors for occurrence and intensity of infection for soil-transmitted helminthiasis (STH), namely Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis and hookworms in a Venezuelan rural community. METHODS: MIF-fixed faecal samples were individually collected for STH testing. The Getis-Ord statistic was used to determine significant STH clustering within 25/50/100 m radiuses around houses. Individual- and house-level factors associated with STH occurrence and intensity of infection were determined using generalized estimating equations. RESULTS: Significant clusters of "wormy" houses for one or multiple parasites were found at distances of 25-50 m around 13 houses. Risk factors differed between occurrence and intensity of infection. Overcrowding in the house increased occurrence of S. stercoralis, T. trichiura and hookworm infections, while poor housing conditions increased A. lumbricoides infection risk. Overcrowding, poor faecal disposal system, economic dependency and lack of basic services differentially influenced the STHs. The "wormy" houses were mainly those built with waste materials, under economic dependency and lacking indoor water supply. CONCLUSIONS: STH distribution in a community is clustered, with significant hotspots of STH occurrence and intensity of infection and different associated risk factors. Targeting the "wormy" houses is expected to affect STH morbidity more efficiently.

Sanitary landfill site selection using multi-criteria decision analysis and analytical hierarchy process: A case study in Azuay province, Ecuador.

Despite environmental regulations in Ecuador, particularly in the Province of Azuay, the solid waste final disposal management is still a socio-environmental problem, worsened by weak governance processes. The province has three sanitary landfills with almost expired service lives. The site selection was based on circumstantial reasons, which makes landfills more likely to cause environmental pollution and, therefore, have negative implications for public health. The largest landfill serves Cuenca and also leases service to other small cities. The remaining two are small and, accordingly, have limited technology and fewer resources. In this context, the main aim of this study is to evaluate the terrain of the province to find the most suitable area for landfill siting. A multi-criteria decision analysis, integrated with a geographical information system and analytical hierarchy process methodology, was conducted. Fourteen factors and seven constraints were simultaneously analysed, divided into technical, environmental, social, and economic categories; 15 of these criteria were from the Ecuadorian Unified Text of the Secondary Legislation of the Environmental Ministry. According to the results, 76.17% of the territory is not suitable for landfill implementation, and the unrestricted area represents the remaining 23.83%. The highest landfill suitability index (70-81%) is located in the south of the province in Santa Isabel, Oña, and Nabón cantons, which are dry and clay-rich areas.

Recent wildfires in Central Chile: Detecting links between burned areas and population exposure in the wildland urban interface.

Wildfires are gaining importance in the Mediterranean regions owing to climate change and landscape changes due to the increasing closeness between urban areas and forests prone to wildfires. We analysed the dry season wildfire occurrences in the Mediterranean region of Central Chile (32°S-39°30' S) between 2000 and 2017, using satellite images to detect burned areas, their landscape metrics and the land use and covers (vegetal) pre-wildfire, in order to determine the population living in areas that may be affected by wildfires. The existing regulations in western Mediterranean countries (Portugal, Spain, France, and Italy) were used to identify and define the wildland-urban interface (WUI) areas, quantifying the people inhabiting them and estimating the population affected by burned areas from 2001 to 2017. We used the Google Earth Engine to process MODIS products and extract both burned areas and land covers. We detected that 25% of the urban population inhabits WUI areas (i.e. Biobío, Araucanía and Valparaíso regions) where the urban population exposed to burned areas exceeds 40%. Most of the land use and land covers affected by wildfires are anthropogenic land covers, classified as savannas, croplands, evergreen broadleaf forests and woody savannas, representing >70% of the burned areas. Urban areas show only 0.6% of the burned surface from 2001 to 2017. We estimate that 55,680 people are potentially affected by wildfires, and 50% of them are in just one administrative region. These results show the imperative need for public policies as a regulating force for establishing WUI areas with the purpose of identifying wildfire risk in urban areas, such as establishing prevention methods as firewalls and prescribed fires.

High prevalence, potential economic impact, and risk factors of Fasciola hepatica in dairy herds in tropical, dry and temperate climate regions in Mexico.

The aims of this study were to determine the prevalence of fasciolosis in cattle herds and its influence on production in order to identify potential risk factors in different climate regions and risk indices in three states of Mexico. The levels of anti-F. hepatica IgG1 antibodies were determined using an indirect ELISA. A total of 837 farm owners or managers answered the questionnaire. The total prevalence of the parasite over the period of January to March 2017 was 63.56%. The highest percentages of positive herds for the categories were found in Hidalgo state (88.33%), the no-risk classification (69.55%) and the temperate climate (76.53%). Overall, the production losses were approximately 0.51 to 1.00 kg of milk per parasitized cow per day. The annual costs of milk production loss per farm were estimated to range from US$2218.39 to US$6424.51, followed by anthelmintic treatment for young stock (US$67.68) and adult cows (US$209.47). Using multivariate logistic regression analysis, six final models were constructed for potential association with the ELISA results and were supported by the climatic, environmental and management factors. The results indicate that different factors were significantly associated with an increased risk of infection for each model.

Prevalence, economic assessment, and risk factors of gastrointestinal nematodes infecting herds in tropical, dry and temperate climate regions in Mexico.

This study investigated exposure to gastrointestinal (GI) nematodes on dairy cattle farms by antibody level determination in bulk tank milk (BTM) samples and its influence on production to detect the risk factors for infection in different climate regions in three states of Mexico. From January to April 2017, BTM samples were collected from 1058 dairy cattle herds and used to establish three Köppen climate classes (tropical, dry and temperate) and states of Mexico. A questionnaire on farm management was applied. The overall herd prevalence of parasites was 67.20%. The highest percentage of positive herds was detected in Veracruz state (78.45%). In addition, the highest prevalence among the climate regions was found in the tropical climate (78.59%). In general, production losses were approximately 1.37-1.78 kg of milk/cow per day. The annual costs of milk production losses per farm were estimated for three different climate regions, ranging between $5541.49 and 6982.50 US$, and those in the three states varied between 5974.10 and 8660.06 US$. The costs for anthelmintic treatments for young stock and adult cows ranged between 57.51 and 192.75 US$, respectively, among the three climate regions and between 46.02 and 189.49 US$, respectively, among the three states. The overall annual costs of milk yield loss per cow were estimated to be 150.74 US$ for the climate regions and 190.54 US$ for the three states of Mexico, followed by the treatment costs for young stock (4.02 US$) and adult cows (3.99 US$). The results suggest that the economic losses due to GI nematodes in Mexican dairy herds are approximately 248 million US$ per annum. Four final models were built based on multivariate logistic regression for potential statistical association from the ELISA results using climatic/environmental and management factors so that each model used different risk factors that were significantly associated with helminth infections in dairy herds.

Bulk tank milk ELISA to detect IgG1 prevalence and clustering to determine spatial distribution and risk factors of Fasciola hepatica-infected herds in Mexico.

Fasciola hepatica is a helminth parasite that causes huge economic losses to the livestock industry worldwide. Fasciolosis is an emerging foodborne zoonotic disease that affects both humans and grazing animals. This study investigated the associations between climatic/environmental factors (derived from satellite data) and management factors affecting the spatial distribution of this liver fluke in cattle herds across different climate zones in three Mexican states. A bulk-tank milk (BTM) IgG1 enzyme-linked immunosorbent assay (ELISA) test was used to detect F. hepatica infection levels of 717 cattle herds between January and April 2015. Management data were collected from the farms by questionnaire. The parasite's overall herd prevalence and mean optical density ratio (ODR) were 62.76% and 0.67, respectively. The presence of clustered F. hepatica infections was studied using the spatial scan statistic. Three marked clusters in the spatial distribution of the parasite were observed. Logistic regression was used to test three models of potential statistical association from the ELISA results using climatic, environmental and management variables. The final model based on climatic/environmental and management variables included the following factors: rainfall, elevation, proportion of grazed grass in the diet, contact with other herds, herd size, parasite control use and education level as significant predictors. Geostatistical kriging was applied to generate a risk map for the presence of parasites in dairy herds in Mexico. In conclusion, the spatial distribution of F. hepatica in Mexican cattle herds is influenced by multifactorial effects and should be considered in developing regionally adapted control measures.

Bulk tank milk prevalence and production losses, spatial analysis, and predictive risk mapping of Ostertagia ostertagi infections in Mexican cattle herds.

This study investigated the prevalence, production losses, spatial clustering, and predictive risk mapping in different climate zones in five states of Mexico. The bulk tank milk samples obtained between January and April 2015 were analyzed for antibodies against Ostertagia ostertagi using the Svanovir ELISA. A total of 1204 farm owners or managers answered the questionnaire. The overall herd prevalence and mean optical density ratio (ODR) of parasite were 61.96% and 0.55, respectively. Overall, the production loss was approximately 0.542 kg of milk per parasited cow per day (mean ODR = 0.92, 142 farms, 11.79%). The spatial disease cluster analysis using SatScan software indicated that two high-risk clusters were observed. In the multivariable analysis, three models were tested for potential association with the ELISA results supported by climatic, environmental, and management factors. The final logistic regression model based on both climatic/environmental and management variables included the factors rainfall, elevation, land surface temperature (LST) day, and parasite control program that were significantly associated with an increased risk of infection. Geostatistical kriging was applied to generate a risk map for the presence of parasite in dairy cattle herds in Mexico. The results indicate that climatic and meteorological factors had a higher potential impact on the spatial distribution of O. ostertagi than the management factors.

Spatial analysis of the prevalence of schistosomiasis in an endemic coastal area in north-eastern Brazil.

Due to contact and misuse of water drainage channels, schistosomiasis has spread and become a constant concern in northeastern Brazil. The aim of this study was to monitor human cases of Schistosomiasis mansoni and the breeding areas of the snail intermediate host Biomphalaria glabrata through spatial analysis in a community named Invasão do Canal do Guaxinim, located in Barra dos Coqueiros City in an endemic coastal part of the state of Sergipe, Brazil. This research was performed as a cross-sectional epidemiological study conducted with parasitological and malacological surveys. To verify the spatial analysis, a two-year spatial point pattern analysis was performed by means of Kernel intensity estimation using TerraView software 4.2.2. A schistosomiasis prevalence reduction from 8.1% (2013) to 4.9% (2014) was observed but mild infection prevailed in adolescents and/or young adults during the two-year study. In malacological research, 387 specimens of snails of the genus B. glabrata were collected and all were negative with regard to schistosomiasis. Spatial analysis showed a strong, spatial trend of increased transmission risk areas north and south of the community, both in 2013 and 2014. In Invasão do Canal do Guaxinim itself, the increased risk was only seen in the northern part. When combined, the human and the malacological spatial analyses constituted an important methodological approach for monitoring and controlling this parasitic disease.

Spatial distribution of bovine cysticercosis-A retrospective study in Brazil from 2010 through 2015.

Geographical Information Systems (GIS) is frequently used in the control of animal diseases. In Brazil, the most impacting economical loss in the beef supply chain is bovine cysticercosis. This study focused on assessing the prevalence and geospatial distribution of bovine cysticercosis in 19 Brazilian states. To this, we gathered data from 146,346,244 bovines slaughtered between the years of 2010 and 2015. The observed prevalence was 0.62% (C.I. 0.62-0.63). In total, 30.86% cysticerci were viable, while 69.14% were unviable. Bovine cysticercosis cases had a significant decrease (p<0.05) during this period. The states of Paraná (2.01%; C.I. 2.00-2.02), Santa Catarina (1.96%; C.I. 1.93-2.00), São Paulo (1.77%; C.I. 1.76-1.77), Rio Grande do Sul (1.63%; C.I. 1.60-1.63) and Mato Grosso do Sul (0.80%; C.I. 0.80-0.80) had the highest prevalence values. In some states a significant (p<0.05) decreasing trend was detected in the prevalence. In conclusion, Taenia-saginata-cysticercosis remains endemic in Brazil and interventions are necessary to maintain Brazilian beef competitive in the international food market and improve food safety to population.

Spatial and temporal distribution of American cutaneous leishmaniasis in Acre state, Brazil.

BACKGROUND: Acre has reported the highest incidence of American cutaneous leishmaniasis (ACL) in Brazil in recent years. The present study seeks to identify high and low risk agglomerations of ACL in space and space-time during the period from 2007 to 2013 in Acre, and also to characterize the occurrence of the disease in time and according to sociodemographic variables. METHODS: This is an ecological study, the study population of which consisted of autochthonous ACL cases notified in the municipalities of Acre by an epidemiological surveillance system. Scan statistics of SaTScan™ software were used to identify spatial and space-time clusters. In addition, the cases were characterized by sex, age, home situation (in a rural or urban area), and temporal tendency. RESULTS: Acre reported an incidence rate of 12.4 cases per 10 000 inhabitant-years in the study period, with the rates varied greatly (standard deviation of 21.8) among their 22 municipalities. One agglomeration of high risk and three of low risk were detected in space and space-time. Four of the five micro-regions of Acre presented a stationary temporal tendency. The profile of transmission varied according to the micro-region. Generally speaking, the disease occurred more often among young people, those of male gender, and those living in rural areas. CONCLUSIONS: Acre has stood out within the Brazilian national context due to its high rates of ACL incidence in the central region of the Acre Valley. The high rates in the micro-region of Brasiléia are related to the disease's intra/peridomiciliary occurrence, and it would seem that the municipality of Sena Madureira is approaching a transmission pattern similar to that of Brasiléia. In other micro-regions, the profile of the disease's transmission is mainly related to the forest/sylvatic cycle of ACL.

A spatial fuzzy logic approach to urban multi-hazard impact assessment in Concepción, Chile.

Even though most cities are exposed to more than one hazard, local planners and decision-makers still have a limited understanding of the exposure and sensitivity to and the spatial distribution of hazards. We examine the impact of multiple hazards in the Concepción Metropolitan Area (CMA), Chile. A flexible methodology based on spatial fuzzy logic modelling was developed to explore the impact of weather-related hazards, including coastal flooding, fluvial flooding, water scarcity, heat stress, and wildfire. 32 indicators were standardised and then aggregated through a stepwise approach into a multi-hazard impact index. We find that all the municipalities in the CMA increased their level of impact between 1992 and 2002, due to a larger increase in the exposure rather than the modest decrease in sensitivity. Municipal sensitivity was driven mostly by changes in the population's age structure. Wildfires and water scarcity appeared to have the largest impact on all municipalities. Fuzzy modelling offered high flexibility in the standardisation and aggregation of indicators with diverse characteristics, while also providing a means to explore how the interaction of numerous indicators influenced the index. The resulting maps can help identify indicators, components, and hazards or combinations of hazards that most influence the impact on municipalities. The results can be used to improve and promote dialogue among policy-makers and stakeholders regarding prioritisation of resources for urban development in ways that can also reduce exposure and sensitivity and lower vulnerability to climate change. The methods presented can be adapted to other cities.

Spatial Association of Canine Rabies Outbreak and Ecological Urban Corridors, Arequipa, Peru.

In the city of Arequipa, Peru, a rabid dog was detected in March 2015, marking the reintroduction of the rabies virus in the area; more rabid dogs have been detected since then. The presence of free-roaming dogs in Arequipa seems to be higher in dry water channels, which are widespread in the city. We created a geographic information system (GIS) with surveillance data on the location of rabid dogs detected during the first year of the outbreak, as well as the water channels. We conducted a spatial analysis using Monte Carlo simulations to determine if detected rabid dogs were closer to the water channels than expected. Thirty rabid dogs were detected during the first year of the outbreak, and they were statistically associated with the water channels (average distance to closest water channel = 334 m; p-value = 0.027). Water channels might play a role in the ecology of free-roaming dog populations, functioning as ecological corridors. Landscape ecology could assist in understanding the impact of these urban structures on control activities and the persistence of transmission.

Spatial Approach of Perinatal Mortality in São Paulo State, 2003-2012 / Análise espacial da mortalidade perinatal no estado de São Paulo, de 2003 a 2012

Abstract Objectives To identifying spatial patterns in the distribution of perinatal mortality in the state of São Paulo from 2003 to 2012. Methods An ecological and exploratory study with data on perinatal mortality rates of every thousand live births, which were registered on the digital database containing 645 municipalities in the state of São Paulo within the periods of 2003 to 2007 and 2008 to 2012. The spatial analysis provided Moran’s index (MI) and thematic maps of rates, and the Moran maps of both periods were drawn. The average rates were compared by Student’s t test. The TerraView 4.2.2 software (INPE, S. José dos Campos, Brazil) was also used. Results There were 49,485 perinatal deaths during the first period, at a rate of 17.90 deaths/1,000 live births (standard deviation [SD] = 7.0; MI = 0.14; p = 0.01), and 44,582 perinatal deaths during the second period, at a rate of 16.40 deaths/1,000 live births (SD = 11.14; MI = 0.04; p = 0.03). These rates are statistically different (p < 0.01). There was a decrease in these rates in 413 municipalities when comparing the two periods. The Moran map has identified 35 municipalities that require special attention, which are located in the Eastern, Southwestern, Western and Northwestern regions of São Paulo state. Conclusion The study provides municipal managers with subsidies so they can minimize these rates by implementing public policies and taking better care of pregnant women and newborns.

Resumo Objetivo Identificar padrões espaciais na distribuição de mortalidade perinatal no Estado de São Paulo no período de 2003 a 2012. Métodos Estudo ecológico e exploratório, com dados sobre as taxas de mortalidade perinatal por mil nascidos vivos e inseridos em malha digital dos 645 municípios do estado de São Paulo entre 2003 e 2007 e 2008 e 2012. A análise espacial forneceu o índice de Moran (IM), e foram construídos mapas temáticos das taxas e o mapa de Moran de ambos os períodos. As taxas médias foram comparadas utilizando o teste t de Student. Utilizou-se o programa Terra View 4.2.2. Resultados Foram 49.485 óbitos perinatais no primeiro período, taxa de 17,90 óbitos/1.000 nascidos vivos (desvio-padrão [DP] = 7,0; IM = 0,14; p = 0,01), e 44.582 óbitos perinatais no segundo período, taxa de 16,40 óbitos/1.000 nascidos vivos (DP = 11,14; IM = 0,04; p = 0,03). Estas taxas são diferentes (p < 0,01). Houve diminuição destas taxas em 413 municípios quando comparados os dois períodos. O mapa de Moran identificou 35 municípios localizados nas regiões Leste, Sudoeste, Oeste e Noroeste, que merecem uma atenção especial. Conclusão O estudo fornece subsídios para que os gestores municipais possam minimizar estas taxas, implantando políticas públicas e melhor atendimento às gestantes e recém-nascidos.

Spatial analysis for the identification of risk areas for schistosomiasis mansoni in the State of Sergipe, Brazil, 2005-2014

Abstract INTRODUCTION: Schistosomiasis is a parasitic infectious disease with a worldwide prevalence. The objective of this work is to identify risk areas for schistosomiasis mansoni transmission in the State of Sergipe, Brazil, during the period from 2005 to 2014. METHODS: We conducted an epidemiological study with secondary data from the Information System Control Program of Schistosomiasis [Sistema de Informação do Programa de Controle da Esquistossomose (SISPCE)]. Temporal trends were analyzed to obtain the annual percentage change (APC) in the rates of annual prevalence. In addition to the description of general indicators of the disease, the spatial analysis was descriptive, by means of the estimator of intensity kernel, and showed spatial dependence by indicators of global Moran (I) and Local Index of Spatial Association (LISA). Thematic maps of spatial distribution were made, identifying priority intervention areas in need of healthcare. RESULTS: There were 78,663 cases of schistosomiasis, with an average of 8.7% positivity recorded; 79.8% of the cases were treated, and Sergipe showed a decreasing positive trend (APC: -2.78). There was the presence of spatial autocorrelation and a significant global Moran index (I = 0.19; p-value = 0.03). We identified clusters of high-risk areas, mainly located in the northeast and southcentral of the state, which each had equally high infection rates. CONCLUSIONS: There was a decreasing positive trend of schistosomiasis in Sergipe. Spatial analysis identified the geographic distribution of risk and allowed the definition of priority areas for the maintenance and intensification of control interventions.

Assessing urban adaptive capacity to climate change.

Despite the growing number of studies focusing on urban vulnerability to climate change, adaptive capacity, which is a key component of the IPCC definition of vulnerability, is rarely assessed quantitatively. We examine the capacity of adaptation in the Concepción Metropolitan Area, Chile. A flexible methodology based on spatial fuzzy modelling was developed to standardise and aggregate, through a stepwise approach, seventeen indicators derived from widely available census statistical data into an adaptive capacity index. The results indicate that all the municipalities in the CMA increased their level of adaptive capacity between 1992 and 2002. However, the relative differences between municipalities did not change significantly over the studied timeframe. Fuzzy overlay allowed us to standardise and to effectively aggregate indicators with differing ranges and granularities of attribute values into an overall index. It also provided a conceptually sound and reproducible means of exploring the interplay of many indicators that individually influence adaptive capacity. Furthermore, it captured the complex, aggregated and continued nature of the adaptive capacity, favouring to deal with gaps of data and knowledge associated with the concept of adaptive capacity. The resulting maps can help identify municipalities where adaptive capacity is weak and identify which components of adaptive capacity need strengthening. Identification of these capacity conditions can stimulate dialogue amongst policymakers and stakeholders regarding how to manage urban areas and how to prioritise resources for urban development in ways that can also improve adaptive capacity and thus reduce vulnerability to climate change.

Mapa de ocupaciones, riesgos laborales y recursos en salud ocupacional / Map of jobs, working risks and resources in occupational health

INTRODUCCIÓN: La gestión y el desarrollo acelerado de la salud de los trabajadores en el país demandan la introducción de tecnología de punta para optimizar sus acciones. OBJETIVOS. Elaborar una herramienta que permita de forma interactiva conocer rápidamente la distribución geográfica de nuestras ocupaciones, el tipo de riesgo y los recursos humanos capacitados con que cuenta el subsistema de salud ocupacional. MÉTODOS. Fue elaborado un sistema automatizado computacional Macromedia (multimedia) Flash MX en una plataforma operativa Windows XP. Se confeccionó una encuesta que inventariaba los datos del municipio en relación con las principales industrias y centros laborales, los riesgos más importantes, los recursos humanos y materiales y la capacitación con que cuentan los recursos humanos dedicados a la salud ocupacional de ese municipio. RESULTADOS. El instrumento permitió el análisis rápido y fácil por áreas geográficas relacionadas con los riesgos del trabajo y demás información solicitada. Los resultados del municipio Arroyo Naranjo son mostrados como ejemplo de aplicabilidad del sistema, así como de sus interacciones.

INTRODUCTION: The management and the accelerated development of the workers' health in our country to demand the introduction of point technology to optimize its actions. OBJECTIVES: To design a tool allows in a interactive way to know quickly the geographical distribution of our jobs, the type of risk and the trained human resources available in the occupational health subsystem. METHODS: A Macromedia (multimedia) automated computed system was designed in a Windows XP functional platform as well as a survey to make an inventory of municipal data in relation to the main industries and working centers, the more important risks, the human and material resources and the training available for human resources involved in the occupational health of this municipality. RESULTS: The tool allows us a fast and easy analysis by geographical areas related to the work risks and other requested information. The results of Arroyo Naranjo municipality are showed as an example of applicability of system, as well as its interactions.

Método AVI (Aquifer Vulnerability Index) para a classificação da vulnerabilidade das águas subterrâneas na região de Campos dos Goytacazes, Rio de Janeiro / AVI method (Aquifer Vulnerability Index) for groundwater vulnerability classification in Campos dos Goytacazes region, Rio de Janeiro, Brazil

O presente artigo apresenta estudos para a classificação da vulnerabilidade àcontaminação das águas subterrãneas na região de Campos dos Goytacazes, Rio de Janeiro. O método AVI (Aquifer Vulnerability Index) foi aplicado, utilizando-se o ferramental do Sistema de Informação Geográfica. O método AVI aplica o conceito de resistência hidráulica, dada pela somatória das taxas de espessura da zona não saturada pelas condutividades hidráulicas do meio. Os mapas resultantes mostraram que a região possui sensibilidade àcontaminação das águas subterrâneas, com classificações que variam de "Alta" a "Extremamente alta" (0-10 dias a 10-100 dias, respectivamente). Essa sensibilidade elevada ocorre pela existência de formações de elevada permeabilidade (areias) e níveis de água rasos, típicas ocorrências do delta do rio Paraíba do Sul. O índice vulnerabilidade Alta ocorre: (1) nas margens direita e esquerda do rio Paraíba do Sul, (2) oeste da área (região de confluência do rio Muriaé com o rio Paraíba do Sul), e (3) parte leste da área urbana de Campos dos Goytacazes. Os terrenos com índice de vulnerabilidade Extremamente alta estão localizados: (1) na porção norte (área do Aquífero Barreiras), (2) na área urbana de Campos dos Goytacazes e dos distritos de Saturnino Braga e Mucurepe, (3) porção leste da área, (4) em terreno entre o canal de Cambaíba e o canal de Andreza, e (5) na porção sul da área (Lagoa Feia). Os resultados mostram a caracterização de um importante parãmetro ambiental da região, pretendendo subsidiar políticas públicas para preservação, proteção e uso racional desse importante manancial subterrâneo.

The present paper shows studies aiming groundwater vulnerability evaluation in Campos dos Goytacazes region, Rio de Janeiro, Brazil. The Aquifer Vulnerability Index (AVI) was the vulnerability method applied, using Geographical Information System tools. The AVI Method has adopted the concept of hydraulic resistivity (sum of taxes among unsaturated thickness and hydraulic conductivity). Result maps showed that the region has groundwater vulnerability to contamination from high to extreme levels. The vulnerability varied from "High" to "Extremely high" indexes (from 0-10 days to 10-100 days, respectively). This high vulnerability was attributed to the occurrence of high permeability formations (sands) and shallow water table, typical from the delta of Paraíba do Sul river. High vulnerability index terrains are situated in the following areas: (1) along the right and left banks of Paraíba do Sul river, (2) in the west side of the study area (region of Muriaé and Paraíba do Sul rivers confluence), and (3) in the east side of urban area of Campos dos Goytacazes. The Extremely high index areas are located: (1) in the north portion (Barreiras aquifer), (2) in urban area of Campos dos Goytacazes, besides Saturnino Braga and Mucurepe districts, (3) eastern region of the studied area, (4) in a portion area between Cambaíba and Andreza water drainage channels, and (5) in terrains situated in the south portion of the area (Feia lake). These results showed an important environmental parameter in the river delta region, intending to subsidized public policies to preserve, to protect, and to sustain this important groundwater resource.

Epidemiología espacial: nuevos enfoques para viejas preguntas Resumen PDF / Epidemiologia espacial: novas abordagens para velhas questões / Spatial epidemiology: new approaches to old questions

La epidemiología espacial se utiliza para describir, cuantificar y explicar las variaciones geográficas de las enfermedades; para evaluar la relación entre la incidencia de enfermedades y posibles factores de riesgo, y para identificar los conglomerados geográficos de las enfermedades. Este artículo revisa los principales aspectos de la epidemiología espacial, empezando con una explicación de la importancia de trazar mapas de los datos de salud, una perspectiva histórica del desarrollo de la disciplina, una descripción de los tipos de datos espaciales, algunos métodos de estadística espacial y la importancia de los Sistemas de Información Geográfica (SIG) en el análisis de datos referenciados espacialmente.Algunas aplicaciones de los SIG en salud bucal se presentan también.

Spatial Epidemiology is used to describe, quantify and explain the geographical variations of diseases, to evaluate the association between the incidence of diseases and potential risk factors and to identify spatial clusters of diseases. This article goes through the main aspects of spatial epidemiology, starting with an explanation of the importance of mapping health data, an historical perspective of the development of the discipline, a description of spatial data types, some methods of spatial statistics, and the importance of Geographical Information Systems (GIS) in the analysis of spatially-referenced data. Some applications ofGIS regarding oral health are presented.

Evaluation of a linear spectral mixture model and vegetation indices (NDVI and EVI) in a study of schistosomiasis mansoni and Biomphalaria glabrata distribution in the state of Minas Gerais, Brazil

This paper analyses the associations between Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) on the prevalence of schistosomiasis and the presence of Biomphalaria glabrata in the state of Minas Gerais (MG), Brazil. Additionally, vegetation, soil and shade fraction images were created using a Linear Spectral Mixture Model (LSMM) from the blue, red and infrared channels of the Moderate Resolution Imaging Spectroradiometer spaceborne sensor and the relationship between these images and the prevalence of schistosomiasis and the presence of B. glabrata was analysed. First, we found a high correlation between the vegetation fraction image and EVI and second, a high correlation between soil fraction image and NDVI. The results also indicate that there was a positive correlation between prevalence and the vegetation fraction image (July 2002), a negative correlation between prevalence and the soil fraction image (July 2002) and a positive correlation between B. glabrata and the shade fraction image (July 2002). This paper demonstrates that the LSMM variables can be used as a substitute for the standard vegetation indices (EVI and NDVI) to determine and delimit risk areas for B. glabrata and schistosomiasis in MG, which can be used to improve the allocation of resources for disease control.

A geoprocessing approach for studying and controlling schistosomiasis in the state of Minas Gerais, Brazil

Geographical information systems (GIS) are tools that have been recently tested for improving our understanding of the spatial distribution of disease. The objective of this paper was to further develop the GIS technology to model and control schistosomiasis using environmental, social, biological and remote-sensing variables. A final regression model (R² = 0.39) was established, after a variable selection phase, with a set of spatial variables including the presence or absence of Biomphalaria glabrata, winter enhanced vegetation index, summer minimum temperature and percentage of houses with water coming from a spring or well. A regional model was also developed by splitting the state of Minas Gerais (MG) into four regions and establishing a linear regression model for each of the four regions: 1 (R² = 0.97), 2 (R² = 0.60), 3 (R² = 0.63) and 4 (R² = 0.76). Based on these models, a schistosomiasis risk map was built for MG. In this paper, geostatistics was also used to make inferences about the presence of Biomphalaria spp. The result was a map of species and risk areas. The obtained risk map permits the association of uncertainties, which can be used to qualify the inferences and it can be thought of as an auxiliary tool for public health strategies.