Identification of optimum scopes of environmental factors for snails using spatial analysis techniques in Dongting Lake Region, China

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Background

Owing to the harmfulness and seriousness of Schistosomiasis japonica in China, the control and prevention of S. japonica transmission are imperative. As the unique intermediate host of this disease, Oncomelania hupensis plays an important role in the transmission. It has been reported that the snail population in Qiangliang Lake district, Dongting Lake Region has been naturally declining and is slowly becoming extinct. Considering the changes of environmental factors that may cause this phenomenon, we try to explore the relationship between circumstance elements and snails, and then search for the possible optimum scopes of environmental factors for snails.

Methods

Moisture content of soil, pH, temperature of soil and elevation were collected by corresponding apparatus in the study sites. The LISA statistic and GWR model were used to analyze the association between factors and mean snail density, and the values in high-high clustered areas and low-low clustered areas were extracted to find out the possible optimum ranges of these elements for snails.

Results

A total of 8,589 snail specimens were collected from 397 sampling sites in the study field. Besides the mean snail density, three environmental factors including water content, pH and temperature had high spatial autocorrelation. The spatial clustering suggested that the possible optimum scopes of moisture content, pH, temperature of the soil and elevation were 58.70 to 68.93%, 6.80 to 7.80, 22.73 to 24.23°C and 23.50 to 25.97 m, respectively. Moreover, the GWR model showed that the possible optimum ranges of these four factors were 36.58 to 61.08%, 6.541 to 6.89, 24.30 to 25.70°C and 23.50 to 29.44 m, respectively.

Conclusion

The results indicated the association between snails and environmental factors was not linear but U-shaped. Considering the results of two analysis methods, the possible optimum scopes of moisture content, pH, temperature of the soil and elevation were 58.70% to 68.93%, 6.6 to 7.0, 22.73°C to 24.23°C, and 23.5 m to 26.0 m, respectively. The findings in this research will help in making an effective strategy to control snails and provide a method to analyze other factors.

Related collections

Most cited references 20

Record: found
Abstract: found
Article: not found

Geographically weighted Poisson regression for disease association mapping.

T Nakaya, M Charlton, Julie Fotheringham … (2005)

This paper describes geographically weighted Poisson regression (GWPR) and its semi-parametric variant as a new statistical tool for analysing disease maps arising from spatially non-stationary processes. The method is a type of conditional kernel regression which uses a spatial weighting function to estimate spatial variations in Poisson regression parameters. It enables us to draw surfaces of local parameter estimates which depict spatial variations in the relationships between disease rates and socio-economic characteristics. The method therefore can be used to test the general assumption made, often without question, in the global modelling of spatial data that the processes being modelled are stationary over space. Equally, it can be used to identify parts of the study region in which 'interesting' relationships might be occurring and where further investigation might be warranted. Such exceptions can easily be missed in traditional global modelling and therefore GWPR provides disease analysts with an important new set of statistical tools. We demonstrate the GWPR approach applied to a data set of working-age deaths in the Tokyo metropolitan area, Japan. The results indicate that there are significant spatial variations (that is, variation beyond that expected from random sampling) in the relationships between working-age mortality and occupational segregation and between working-age mortality and unemployment throughout the Tokyo metropolitan area and that, consequently, the application of traditional 'global' models would yield misleading results. Copyright (c) 2005 John Wiley & Sons, Ltd.

0 comments Cited 92 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: found

Is Open Access

Factors impacting on progress towards elimination of transmission of schistosomiasis japonica in China

Yi-Biao Zhou, Song Liang, Qing-Wu Jiang (2012)

Over the past decades China has made a great stride in controlling schistosomiasis, eliminating transmission of Schistosoma japonicum in 5 provinces and remarkably reducing transmission intensities in the rest of the seven endemic provinces. Recently, an integrated control strategy, which focuses on interventions on humans and bovines, has been implemented throughout endemic areas in China. This strategy assumes that a reduction in transmission of S. japonicum from humans and bovines to the intermediate Oncomelania snail host would eventually block the transmission of this parasite, and has yielded effective results in some endemic areas. Yet the transmission of S. japonicum is relatively complicated – in addition to humans and bovines, more than 40 species of mammalians can serve as potential zoonotic reservoirs. Here, we caution that some factors – potential roles of other mammalian reservoirs and human movement in sustaining the transmission, low sensitivity/specificity of current diagnostic tools for infections, praziquantel treatment failures, changes in environmental and socio-economic factors such as flooding in key endemic areas - may pose great obstacles towards transmission interruption of the parasite. Assessing potential roles of these factors in the transmission and implications for current control strategies aiming at transmission interruption is needed.

0 comments Cited 46 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Tobacco outlet density and demographics: analysing the relationships with a spatial regression approach.

D. Yu, N.A. Peterson, M.A. Sheffer … (2010)

Studies of relationships between tobacco sales and socio-economic/sociodemographic characteristics are well documented. However, when analysing the data that are collected on geographic areas, the spatial effects are seldom considered, which could lead to potential misleading analytical results. This study addresses this concern by applying the spatial analysis method in studying how socio-economic factors and tobacco outlet density are related in New Jersey, USA. A spatial regression method applied to tobacco outlet and socio-economic data obtained in 2004 in New Jersey, USA. This study assessed the association between tobacco outlet density and three demographic correlates - income, race and ethnicity - at the tract level of analysis for one state in the north-eastern USA. Data for 1938 residential census tracts in the state of New Jersey were derived from 2004 licences for 13,984 tobacco-selling retail outlets. Demographic variables were based on 2000 census data. When applying a regression model, the residuals of an ordinary least squared (OLS) estimation were found to exhibit strong spatial autocorrelation, which indicates that the estimates from the OLS model are biased and inferences based on the estimates might be misleading. A spatial lag model was employed to incorporate the potential spatial effects explicitly. Agreeing with the OLS residual autocorrelation test, the spatial lag model yields a significant coefficient of the added spatial effect, and fits the data better than the OLS model. In addition, the residuals of the spatial regression model are no longer autocorrelated, which indicates that the analysis produces more reliable results. More importantly, the spatial regression results indicate that tobacco companies attempt to promote physical availability of tobacco products to geographic areas with disadvantageous socio-economic status. In New Jersey, the percentage of Hispanics seems to be the dominant demographic factor associated with tobacco outlet distribution, followed by median household income and percentage of African Americans. This research applied a spatial analytical approach to assess the association between tobacco outlet density and sociodemographic characteristics in New Jersey at the census tract level. The findings support the common wisdom in the public health research domain that tobacco outlets are more densely distributed in socio-economically disadvantaged areas. However, incorporating the spatial effects explicitly in the analysis provides less biased and more reliable results than traditional methods. Copyright 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

0 comments Cited 39 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Contributors

Jin-Yi Wu

Yi-Biao Zhou

Lin-Han Li

Sheng-Bang Zheng

Song Liang

Ashley Coatsworth

Guang-Hui Ren

Xiu-Xia Song

Zhong He

Bin Cai

Jia-Bian You

Qing-Wu Jiang

Journal

Journal ID (nlm-ta): Parasit Vectors

Journal ID (iso-abbrev): Parasit Vectors

Title: Parasites & Vectors

Publisher: BioMed Central

ISSN (Electronic): 1756-3305

Publication date Collection: 2014

Publication date (Electronic): 9 May 2014

Volume: 7

Page: 216

Affiliations

[1 ]Department of Epidemiology, School of Public Health, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China

[2 ]Key Laboratory of Public Health Safety, Ministry of Education, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China

[3 ]Center for Tropical Disease Research, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China

[4 ]Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA

[5 ]Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA

[6 ]Department of Epidemiology, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA

[7 ]Hunan station for Schistosomiasis Control, Changsha, Hunan Province 410000, China

[8 ]Junshan office of Leading Group for Schistosomiasis Control, Yueyang, Hunan province 414000, China

[9 ]Junshan station for Schistosomiasis Control, Yueyang, Hunan Province 414000, China

[10 ]Qianlianghu station for Schistosomiasis Control, Yueyang, Hunan Province 414000, China

Article

Publisher ID: 1756-3305-7-216

DOI: 10.1186/1756-3305-7-216

PMC ID: 4025561

PubMed ID: 24886456

SO-VID: d40407dd-3c58-4af0-b0c6-1c2ca6079dff

License:

This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Identification of optimum scopes of environmental factors for snails using spatial analysis techniques in Dongting Lake Region, China

Read this article at

Abstract

Background

Methods

Results

Conclusion

Related collections

Malaria vaccine development

Most cited references 20

Geographically weighted Poisson regression for disease association mapping.

Factors impacting on progress towards elimination of transmission of schistosomiasis japonica in China

Tobacco outlet density and demographics: analysing the relationships with a spatial regression approach.

Author and article information

Contributors

Journal

Affiliations

Article

History

Categories

Comments

Comment on this article

Similar content 244

Cited by 13

Most referenced authors 143