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

Guimarães, Ricardo José de Paula Souza e; Freitas, Corina da Costa; Dutra, Luciano Vieira; Scholte, Ronaldo Guilherme Carvalho; Martins-Bedé, Flávia Toledo; Fonseca, Fernanda Rodrigues; Amaral, Ronaldo; Drummond, Sandra; Felgueiras, Carlos; Oliveira, Guilherme; Carvalho, Omar S.

doi:10.1590/s0074-02762010000400030

Cited by 30 publications

(36 citation statements)

References 35 publications

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“…In 2009, the Pan American Health Organization (PAHO) put forward an agenda for the control and elimination of neglected diseases and other poverty-related infections in Latin America and the Caribbean (PAHO, 2009;Schneider et al, 2011;Colston and Saboyá, 2013). Interventions that focus on priority areas are required to improve the cost-effectiveness of control programmes and, among the proposed deliverables, reliable maps of the distribution of neglected tropical diseases along with estimates of the numbers infected play an important role Guimarães et al, 2010;Ault et al, 2012;Scholte et al, 2012a;Colston and Saboyá, 2013).…”

Section: Introductionmentioning

confidence: 99%

Spatial analysis and risk mapping of soil-transmitted helminth infections in Brazil, using Bayesian geostatistical models

et al. 2013

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Abstract. Soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) negatively impact the health and wellbeing of hundreds of millions of people, particularly in tropical and subtropical countries, including Brazil. Reliable maps of the spatial distribution and estimates of the number of infected people are required for the control and eventual elimination of soil-transmitted helminthiasis. We used advanced Bayesian geostatistical modelling, coupled with geographical information systems and remote sensing to visualize the distribution of the three soil-transmitted helminth species in Brazil. Remotely sensed climatic and environmental data, along with socioeconomic variables from readily available databases were employed as predictors. Our models provided mean prevalence estimates for A. lumbricoides, T. trichiura and hookworm of 15.6%, 10.1% and 2.5%, respectively. By considering infection risk and population numbers at the unit of the municipality, we estimate that 29.7 million Brazilians are infected with A. lumbricoides, 19.2 million with T. trichiura and 4.7 million with hookworm. Our model-based maps identified important risk factors related to the transmission of soiltransmitted helminths and confirm that environmental variables are closely associated with indices of poverty. Our smoothed risk maps, including uncertainty, highlight areas where soil-transmitted helminthiasis control interventions are most urgently required, namely in the North and along most of the coastal areas of Brazil. We believe that our predictive risk maps are useful for disease control managers for prioritising control interventions and for providing a tool for more efficient surveillance-response mechanisms.

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Section: Introductionmentioning

confidence: 99%

Spatial analysis and risk mapping of soil-transmitted helminth infections in Brazil, using Bayesian geostatistical models

et al. 2013

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“…Snail distribution and consequently also cases of schistosomiasis could be modelled from the environmental and climatic characteristics and therefore the maps of the distribution of Biomphalaria obtained can be used as predictors for the distribution of S. mansoni. Since schistosomiasis is a disease with distribution determined by the structural and contextual components of the environment, geoprocessing should be a powerful tool for unravelling the causal factors and analyzing the risk of occurrence of this disease in space and time (Guimarães et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…In particular, these techniques have been used to model diseases such as schistosomiasis in studies developed by Guimarães et al (2009Guimarães et al ( , 2010Guimarães et al ( , 2012 to estimate the spatial distribution of Biomphalaria snails in the state of Minas Gerais. Furthermore, Scholte et al (2012) used modelling based on environmental characteristics with this aim in the whole country.…”

Section: Geospatial Healthmentioning

confidence: 99%

Modelling of the distribution of Biomphalaria glabrata and Biomphalaria straminea in the metropolitan region of Recife, Pernambuco, Brazil

Barbosa¹,

Guimarães²,

Loyo³

et al. 2016

Geospat Health

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The occurrence of schistosomiasis is directly linked to the presence of its snail intermediate host Biomphalaria spp. Knowledge of geographical distribution, habitats and behaviour of these snails in relation to the climate is essential for guiding measures for disease prevention and control. This study aims to model the distribution of B. glabrata and B. straminea in schistosomiasis non-endemic areas of the metropolitan region of Recife (MRR) based on environmental data and estimates of snail distributions in endemic and neighbouring areas. We applied Kriging with the aim of determining the spatial distribution of these two snail species and MaxEnt for modelling their ecological behaviour. Kriging showed that the North and the Centre of the MRR were generally either snail-free or contained only B. straminea, while both snail species could be found in the South. MaxEnt supported our observation that the northern and southern coastal regions were favoured by B. glabrata and diurnal mean temperature variation; July rainfall and November rainfall were the three variables favouring Biomphalaria breeding sites that contributed the most in the predictive model we developed. The study showed the location of areas suitable to Biomphalaria spp. and therefore at potential risk, first for invasion of these snails and later for the development of new schistosomiasis-endemic areas. This information should be useful, not only to estimate expansion possibilities of this disease in the MRR, but also to point out the climatic variables that would contribute to this expansion, thereby allowing timely application of prevention and control measures.

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“…The presence of Biomphalaria species was previously reported in the municipalities of Piau, Rio Novo and Juiz de Fora 15,18,31 , although considering their geographical location, only Juiz de Fora has been surveyed 18 . Models to estimate the prevalence of schistosomiasis have been perfomed in the State of Minas Gerais 14,[32][33][34] and in some Estrada Real municipalities 16 , but in both studies, due to lack of georeferenced information for Biomphalaria, only data concerning the prevalence of human schistosomiasis and Biomphalaria species in relation to the municipality were used. In this study, all the sites where the occurrence of Biomphalaria was verified were mapped using GPS.…”

Section: Discussionmentioning

confidence: 99%

“…Knowing the exact location of the breeding/water collections of the intermediate host participant in the chain of transmission of schistosomiasis permits greater flexibility in structuring measures for disease control. Moreover, these data may favor the use of geostatistical techniques, generating predictive values for the occurrence of Biomphalaria at sites in the region with no information regarding the intermediate hosts 34,35 , which could contribute to the drafting of a map of Biomphalaria snails in the State of Minas Gerais.…”

Section: Discussionmentioning

confidence: 99%

Malacological survey of Biomphalaria snails in municipalities along the Estrada Real in the southeast of the State of Minas Gerais, Brazil

Tibiriçá

Mitterofhe²,

Castro³

et al. 2011

Rev. Soc. Bras. Med. Trop.

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Introduction:The increasing practice of ecotourism and rural tourism in the State of Minas Gerais, Brazil, highlights the importance of studies concerning the occurrence of potential intermediate hosts of Schistosoma mansoni. This study aimed to identify species of Biomphalaria snails in municipalities along the Estrada Real, an important Brazilian tourism project. Methods: The specimens were collected in different water collections of 36 municipalities along the Estrada Real in the southeast of the State of Minas Gerais. Biomphalaria species were characterized using both morphological and molecular approaches. The research was conducted between August 2005 and September 2009 and all the sites visited were georeferenced using GPS. Results: Six Biomphalaria species were found in 30 of the 36 municipalities studied: glabrata, tenagophila, straminea, peregrina, occidentalis and schrammi. The first three species of Biomphalaria, recognized as intermediate hosts of S. mansoni, were present in 33.3%, 47.2% and 8.3% of the municipalities studied, respectively. The mollusks were found in different types of water collections and no infection by S. mansoni was detected. The highest occurrence of Biomphalaria concentration was verified in the area covered by the Caminho Novo route (Diamantina/MG to Rio de Janeiro/RJ). Conclusions: Considering the occurrence of schistosomiasis in the State of Minas Gerais and the socioeconomic repercussions involved in the Estrada Real Project, this work focuses on the vulnerability of water collections due to the presence of Biomphalaria mollusks and emphasizes the need for epidemiological surveillance and sanitary and educational measures integrated with the local community and tourism sectors.

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

Cited by 30 publications

References 35 publications

Spatial analysis and risk mapping of soil-transmitted helminth infections in Brazil, using Bayesian geostatistical models

Spatial analysis and risk mapping of soil-transmitted helminth infections in Brazil, using Bayesian geostatistical models

Modelling of the distribution of Biomphalaria glabrata and Biomphalaria straminea in the metropolitan region of Recife, Pernambuco, Brazil

Malacological survey of Biomphalaria snails in municipalities along the Estrada Real in the southeast of the State of Minas Gerais, Brazil

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