Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 May 9:7:216.
doi: 10.1186/1756-3305-7-216.

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

Affiliations

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

Jin-Yi Wu et al. Parasit Vectors. .

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.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Location of sampled bottomland in Dongting Lake Region. Detailed legends: This map shows where the sampled bottomland is located in.
Figure 2
Figure 2
LISA cluster of mean snail density in a bottomland of Dongting Lake Region. Detailed legends: This map shows the spatial cluster locations.
Figure 3
Figure 3
Coefficient and significance of water content in GWR model. Detailed legends: This map shows the value of parameters and its significance in GWR model to illustrate how water content influences mean snail density.
Figure 4
Figure 4
Coefficient and significance of pH in GWR model. Detailed legends: This map shows the value of parameters and its significance in GWR model to illustrate how pH influences mean snail density.
Figure 5
Figure 5
Coefficient and significance of temperature in GWR model. Detailed legends: This map shows the value of parameters and its significance in GWR model to illustrate how temperature influences mean snail density.
Figure 6
Figure 6
Coefficient and significance of elevation in GWR model. Detailed legends: This map shows the value of parameters and its significance in GWR model to illustrate how elevation influences mean snail density.

References

    1. Schistosomiasis-A major public health problem. http://www.who.int/schistosomiasis/en/
    1. Zhou YB, Liang S, Jiang QW. Factors impacting on progress towards elimination of transmission of schistosomiasis japonica in China. Parasit Vectors. 2012;5:275. doi: 10.1186/1756-3305-5-275. - DOI - PMC - PubMed
    1. Hu Y, Zhang ZJ, Chen Y, Wang Z, Gao J, Tao B, Jiang QW. Spatial pattern of schistosomiasis in Xingzi, Jiangxi Province, China: the effects of environmental factors. Parasit Vectors. 2013;6:214. doi: 10.1186/1756-3305-6-214. - DOI - PMC - PubMed
    1. Lin DD, Wu XH, Jiang QW, Lin JJ, Zhou XN. Strategic empHasis for research development of schistosomiasis control in China. Chin J Schisto Contro. 2009;21:1–5. in Chinese.
    1. Zhou XN, Jiang QW, Wang TP, Lin DD, Wu XH. Status and strategy for research development of schistosomiasis control in China. Chin J Schisto Contro. 2005;17:1–3. in Chinese.

Publication types

LinkOut - more resources