Spatial analysis of visceral leishmaniasis in the municipality of Rondonópolis, in the Brazilian State of Mato Grosso, from 2003 to 2012: human, canine and vector distribution in areas of disease transmission (original) (raw)
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Memorias Do Instituto Oswaldo Cruz, 2006
The geographic information system approach has permitted integration between demographic, socio-economic and environmental data, providing correlation between information from several data banks. In the current work, occurrence of human and canine visceral leishmaniases and insect vectors (Lutzomyia longipalpis) as well as biogeographic information related to 9 areas that comprise the city of Belo Horizonte, Brazil, between April 2001 and March 2002 were correlated and georeferenced. By using this technique it was possible to define concentration loci of canine leishmaniasis in the following regions: East; Northeast; Northwest; West; and Venda Nova. However, as for human leishmaniasis, it was not possible to perform the same analysis. Data analysis has also shown that 84.2% of the human leishmaniasis cases were related with canine leishmaniasis cases. Concerning biogeographic (altitude, area of vegetation influence, hydrographic, and areas of poverty) analysis, only altitude showed to influence emergence of leishmaniasis cases. A number of 4673 canine leishmaniasis cases and 64 human leishmaniasis cases were georeferenced, of which 67.5 and 71.9%, respectively, were living between 780 and 880 m above the sea level. At these same altitudes, a large number of phlebotomine sand flies were collected. Therefore, we suggest control measures for leishmaniasis in the city of Belo Horizonte, giving priority to canine leishmaniasis foci and regions at altitudes between 780 and 880 m.
Parasites & vectors, 2014
BackgroundThe physical characteristics of the environment influence the composition, distribution and behavior of the vectors and mammalian hosts involved in the transmission of visceral leishmaniasis (VL), thereby affecting the epidemiology of the disease. In Brazil, urbanization of human VL is a recent phenomenon and represents an issue of particular concern to local health authorities. The present study aimed to establish the degree of spatial dependency between canine and human VL in the municipality of Divinópolis, Minas Gerais, Brazil, and to identify priority risk areas in which stricter control measures should be implemented.MethodsThe selected canine population comprised 3,652 dogs distributed within 11 strata and 1,247 urban blocks. Serum samples were collected between March 2013 and February 2014. Serodiagnosis of dogs was performed using the enzyme-linked immunosorbent assay and the indirect fluorescent-antibody test. The blocks sampled for canine VL and the addresses of...
Spatial analysis of American Visceral Leishmaniasis in Mato Grosso do Sul State, Central Brazil
Summary Objectives: To map American Visceral Leishmaniasis (AVL) in Mato Grosso do Sul State (Central Brazil). Methods: The distribution of AVL was mapped, using the Geographic Information System. Results: The disease was endemic to the Corumba´ Region from 1913 to 1998. Spatial and temporal analysis indicated that the expansion route and dissemination through the State of the disease has been from west to east, coinciding with three different human interventions; two of them, a federal highway and a rail-road, were constructed in the early twentieth century, from east to west, from Bauru city, in São Paulo State, to Corumbá city, in Mato Grosso do Sul State. The third anthropogenic intervention was the construction of a gas pipeline that started in 1998, and attracted thousands of workers. This construction route has the same direction, west to east, and timescale as the observed expansion and dissemination of AVL. Conclusions: The results relate the expansion of the disease to intense human traffic along the route of spread.
Revista da Sociedade Brasileira de Medicina Tropical, 2021
INTRODUCTION: Visceral leishmaniasis has a broad worldwide distribution and constitutes a public health problem in the Northeast of Brazil. Located in this region is the state of Alagoas, where the disease is endemic in humans and where there has been a significant increase in the number of positive dogs. The objective of this study was to describe the temporal and spatial distribution of the cases of human VL in the state of Alagoas with the aim of identifying transmission risk areas in the period from 2007 to 2018. METHODS: The data available in the National Disease Notification System (SINAN-NET) were used. The Bayesian incidence rate and the Moran’s global index were calculated using the Terra View 4.2.2 program, and the maps were created using QGIS2.18.0. RESULTS: From the 102 municipalities, 68.6% (n= 70) had at least one notified case of VL in the years of study. A total of 489 cases were registered, with an average of 40.7 cases per year and an incidence rate of 1.25/100,000...
Cadernos De Saude Publica, 2001
In this paper, we present spatial analysis of the association between all incidents cases of human Visceral Leishmaniasis and seropositive dogs, from 1994 to 1997 in Belo Horizonte, a large Brazilian city. We geocoded 158 human cases and 11,048 seropositive dogs and compared canine prevalence rates with Human Bayesian Incidence rates in the same areas. We also used Knox's test to evaluate the hypothesis of space-time clustering of human cases in the period. Additionally, we used Kernel's maps for seropositive dogs distribution and located the human cases in the resulting smooth maps. We concluded that human and dog rates are correlated. Also, the Visceral Leishmaniasis in Belo Horizonte spread quickly, but apart from the rates' magnitude, it has kept the same spatial pattern through time. We believe it is possible to use this technique to choose areas to implement control measures against Visceral Leishmaniasis in a more efficient way. Resumo Neste artigo, apresentamos uma análise espacial da associação entre todos os casos incidentes de leishmaniose visceral e em cães soropositivos ocorridos em Belo Horizonte no período de 1994 a 1997. Geocodificamos 158 casos humanos e 11.048 cães positivos, comparamos as taxas de prevalência canina por área e as taxas Bayesianas de incidência da doença humana nas mesmas áreas. Usamos o teste de Knox para testar a hipótese de cluster espaço temporal entre os casos humanos no período examinado. Adicionalmente, construímos Mapas de Kernel para cães soropositivos e sobrepusemos os casos humanos em quatro áreas. Os resultados apontam para correlação entre casos humanos e caninos. Além disso, a leishmaniose visceral espalhou-se rapidamente em Belo Horizonte, embora tenha mantido o mesmo padrão durante os anos analisados. Acreditamos ser possível o uso das técnicas empregadas para priorizar áreas onde as medidas de controle devem ser implementadas.
Memórias do Instituto Oswaldo Cruz, 2016
This study aimed to analyse the spatial distribution of human (2007-2013) and canine (2013) visceral leishmaniasis (VL) in the city of Araçuaí, Minas Gerais, Brazil, and identify the socio-environmental factors related to their occurrence. The spatial distribution of human and canine cases was analysed by kernel density estimation (KDE) and the K function. The KDE values were analysed for correlation between human and canine LV and for normalised difference vegetation index (NDVI). Socio-environmental aspects of household structures and surroundings were evaluated. The spatial distribution of human and canine VL cases exhibited a significant aggregated pattern in distances greater than 350 and 75 m, respectively. The higher occurrence of human and canine infection occurred in the central area of the city. A positive correlation between the densities of human and canine cases was observed, as well as a negative correlation between NDVI and densities of human and canine cases. Socio-environmental analysis revealed that the large amount of animals, organic material from trees and deficiencies in environmental sanitation are possibly contributing to the continuation of the transmission cycle of Leishmania infantum in Araçuaí. These results can contribute to the planning by competent agencies to reduce the incidence of infection in the city.
Revista da Sociedade Brasileira de Medicina Tropical
Visceral leishmaniasis (VL) has shown endemic pattern and epidemic episodes in urban and rural areas, however, there are still gaps in knowledge with regards to disease transmission. This study aimed to analyze the spatiotemporal dispersion of VL cases in the municipality of Araçuaí, Minas Gerais. A study of confirmed VL cases was conducted considering the endemic and epidemic periods between 2012 and 2017. The incidence rate was calculated, and for spatial analysis, the kernel map, directional distribution ellipse, and space-time scanning techniques were used. The correlations between VL cases and exposure variables (precipitation, humidity, and temperature) were calculated. The mean incidence of VL in the endemic period was 18.5 (95% confidence interval (CI) 5.9-32.5) and 44.4 in the epidemic period (95%CI, 12.0-28.6) by 100,000 inhabitants. The relative risk for the epidemic period was 2.4 (95% CI 1.4-4.1) when compared to the endemic period. A higher incidence of the disease was observed in rural areas of the municipality. Kernel mapping analysis revealed hotspots in the urban area of the municipality. The directional distribution ellipse encompasses the urban perimeter and part of the rural area of the municipality, expanding eastward during the epidemic period. Spatial analysis revealed a high-risk cluster for VL in rural areas. A positive correlation was observed between VL cases and temperature during the endemic period. Spatial analysis allowed us to outline the epidemiological scenario of human VL cases. These findings may be useful in case surveillance and in the work of health professionals and managers in Brazil.
Parasites & Vectors
Background: In Latin America, Brazil harbors the most cases of human visceral leishmaniasis (HVL). Since the early 1980s, the disease has spread to the urban centers of the north, and now the south and west of Brazil; it reached São Paulo state in the southeast in 1996, and Presidente Prudente in the western region in 2010. Our aim was to describe the spatiotemporal analysis and environmental risk factors associated with the dispersion of VL in Presidente Prudente, an urban setting with recent transmission. Methods: An entomological survey was carried out from 2009 to 2015. A canine visceral leishmaniasis (CVL) serosurvey was performed from 2010 to 2015 using enzyme-linked immunosorbent assays (ELISA), a dual-path platform CVL rapid test, and indirect fluorescent antibodies (IFAT). Data from HVL cases were obtained from the Municipal Surveillance Epidemiology Center from 2013 to 2017. Data on water drainage and forest fragments were obtained from public platforms and irregular solid-waste deposits were determined by monthly inspections of the urban area. Kernel density maps of the distribution of CVL were constructed. Results: From 2009 to 2015, Lutzomyia longipalpis sand flies were found in all seven areas of Presidente Prudente. From 2010 to 2015, 40,309 dogs were serologically screened and 638 showed positive results, i.e. a prevalence rate of 1.6%. From 2013 to 2017, six human cases were diagnosed with a mortality rate of 33.3%. In 2015, 56 points of irregular solid-waste deposits were identified, predominantly in the neighborhoods. Three different hotspots of CVL showed an increased distribution of vectors, seropositive dogs, irregular solid-waste deposits, forest fragments and water drainage. Conclusions: The use of tools that analyze the spatial distribution of vectors, canine and human VL as environmental risk factors were essential to identifying the areas most vulnerable to the spread or maintenance of VL. The results may help public health authorities in planning prevention and control measures to avoid expansion and future outbreaks.
Spatial distribution of canine Visceral Leishmaniasis in Ilha Solteira, São Paulo, Brazil
Engenharia Agrícola, 2012
Visceral Leishmaniasis (VL) is caused by protozoan of genus Leishmania and transmitted by sand flies of genus Lutzomyia, which has been adapted to the peridomicile environment where dogs are their mainly food source, increasing the risk for human cases. In this study, techniques of geoprocessing and spatial statistics were utilized as a contribution to understanding the epidemiological dynamics of VL in the urban area of Ilha Solteira, SP.
Revista da Sociedade Brasileira de Medicina Tropical
Introduction: Visceral leishmaniasis (VL) is an important parasitic disease. We evaluated the epidemiological aspects and spatial distribution of visceral leishmaniasis in Governador Valadares, Brazil. Methods: All cases of VL, registered by the municipal health department, were analyzed and georeferenced. Results: The human mortality rate was 15% and canine seroprevalence rate was 29.0%. Higher numbers of canine VL cases correlated with higher incidence of human cases. Conclusions: The high rate of canine seroprevalence, resurgence of the human disease, and correlation between canine and human VL reinforces the role of the dog in disease transmission within the municipality.