Probing the Spatial Cluster of Meriones Unguiculatus Using the Nest Flea Index Based on GIS Technology
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Accepted Manuscript Title: Probing the spatial cluster of Meriones unguiculatus using the nest flea index based on GIS Technology Author: Dafang Zhuang Haiwen Du Yong Wang Xiaosan Jiang Xianming Shi Dong Yan PII: S0001-706X(16)30182-6 DOI: http://dx.doi.org/doi:10.1016/j.actatropica.2016.08.007 Reference: ACTROP 4009 To appear in: Acta Tropica Received date: 14-4-2016 Revised date: 3-8-2016 Accepted date: 6-8-2016 Please cite this article as: Zhuang, Dafang, Du, Haiwen, Wang, Yong, Jiang, Xiaosan, Shi, Xianming, Yan, Dong, Probing the spatial cluster of Meriones unguiculatus using the nest flea index based on GIS Technology.Acta Tropica http://dx.doi.org/10.1016/j.actatropica.2016.08.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. 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Probing the spatial cluster of Meriones unguiculatus using the nest flea index based on GIS Technology Dafang Zhuang1, Haiwen Du2, Yong Wang1*, Xiaosan Jiang2, Xianming Shi3, Dong Yan3 1 State Key Laboratory of Resources and Environmental Information Systems, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China. 2 College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, China. 3 Institute of Plague Prevention and Control of Hebei Province, Zhangjiakou, China. *Correspondence: Yong Wang, [email protected] 1 Abstract: The nest flea index of Meriones unguiculatus is a critical indicator for the prevention and control of plague, which can be used not only to detect the spatial and temporal distributions of Meriones unguiculatus, but also to reveal its cluster rule. This study used global spatial autocorrelation and spatial hot spot detection methods to describe the relationship between different years and the autocorrelation coefficient of nest flea indexes; it also used a spatial detection method and GIS technology to detect the spatial gathered hot spot of Meriones unguiculatus in the epidemic areas. The results of this study showed that (1) there were statistically significant spatial autocorrelations in the nest flea indexes in 2006, 2012, 2013 and 2014. (2) Most of the distribution patterns of Meriones unguiculatus were statistically significant clusters of high values. (3) There were some typical hot spot regions of plague distributed along the Inner Mongolia plateau, north of China. (4) The hot spot regions of plague were gradually stabilized after increasing and decreasing repeatedly. Generally speaking, the number of hot spot regions showed an accelerated increase from 2005 to 2007, decreased slowly from 2007 to 2008, rapidly increased again after decreasing slowly from 2008 to 2010, showed an accelerated decrease from 2010 to 2011, and ultimately were stabilized after rapidly increasing again from 2011 to 2014. (5) The migration period of the hot spot regions was 2-3 years. The epidemic area of plague moved from southwest to east during 2005, 2007, 2008 and 2010, from east to southwest during 2007 and 2008, from east to west during 2010 and 2011, and from Midwest to east during 2011 and 2014. (6) Effective factors, such as temperature, rainfall, DEM, host density, and NDVI, can affect the spatial cluster of Meriones unguiculatus. The results of this study have important implications for exploring the temporal and spatial distribution law and distribution of the hot spot regions of plague, which can reduce the risk of plague, help support the decision making process for the control and prevention of plague, and form a valuable application for plague research. Keywords:Spatial autocorrelation; GIS; Nest fleas; Meriones unguiculatus 2 1、 Introduction Plague is a natural focal disease and is the first notifiable disease. New epidemic areas have continually been discovered, and the intensity of plague has constantly been enhanced around the world since the 1990s. Plague is a zoonotic, insect-borne, infectious disease with a natural focal infectious endemic that is caused by Yersinia pestis and is spread through the bite of fleas that are naturally infected with plague (Davis et al., 2006). The main mode of glandular plague of transmission is from rodents to fleas to people. The flea is one of the most important groups of medical insects; fleas bite people and livestock to feed on their blood, causing direct damage and the spread of plague and endemic typhus (Nakazawa et al., 2007). Several fleas spread plague bacillus widely between hosts; fleas of higher richness can suppress the immune reactions in hosts, thus the susceptibility of hosts is increased in favour of plague bacillus, which breed to a high density in the hosts, and then the probability of infecting new hosts rises again. The natural epidemic focus of Meriones unguiculatus was discovered in 1954 (Fan et al., 2010; Williams 1974.). Previous research has mainly focused on the general situation of plague epidemic in each epidemic focus (Parmenter et al., 1999), the relationship between plague and environment factors (Zhang et al., 2007), the popularity of plague vector fleas in epidemiology, the relationship between the quantity of vector fleas and meteorological factors (Pham et al., 2009; Li 1999; Zhong 2000) etc. There was a lack of research on the association of the plague epidemic and the quantity of vector fleas with the spatial distribution characteristics of the natural epidemic focus, as well as geographical factors that are associated with the spread of plague, which are not independently distributed in space, and have a complex spatial-temporal topology. The mathematical statistics, ecological and epidemiological methods are unable to analyse the complex spatial-temporal relationships between these geographical factors; thus, it is imperative to solve this problem using a new technology. Geographical Information Systems (GIS) is based on the time-space relationship between surface features using a spatial-temporal analysis of a geographic model with 3 the support of computer. It also analyses multiple dynamic spatial-temporal geographic data, and the new technical system is established for research and decision services (Yang et al., 2010). GIS is a new scientific study method because it has powerful spatial data management and analytical capabilities. Its application to the plague indicates that GIS has extended to more fields than ever before. Yang et al. (2000) analysed the spatial-temporal distribution law and characteristics in the natural foci of China since 1840. Qian et al. (2014) established the plague prevention and control GIS to predict the tendency of plague development using a spatial-temporal model. Eisen et al. (2007a; 2007b) determined the location of plague relative to the human population using the GIS model of a geographical landscape and created the risk map of plague and the established Habitat-Suitability model. Lieshout et al. (2004) performed a spatial clustering analysis on ecological types of plague bacillus in Arizona grassland. Previously, research on the spatial distribution of the plague vector flea, the regularity of the plague vector flea distribution and the spatial aggregation of the plague vector flea by GIS was uncommon. This study combines spatial statistical analysis research methods using spatial analysis tools to investigate the Meriones unguiculatus nest flea indexes and explore the regularity and aggregation of the nest flea index distribution, which provided a new method and technology for analysing plague and assisted in decisions regarding plague prevention and control. 2、 Materials and methods 2.1 The general situation of the survey region The Meriones unguiculatus natural epidemic focus is mainly distributed in the Inner Mongolian Plateau, also known as the Inner Mongolian Plateau Meriones unguiculatus epidemic focus (Thomas et al., 2004). The Meriones unguiculatus natural epidemic focus is located in the southwest edge of the ordos plateau, and the boundary is the Huanghe River, which divided the natural epidemic focus into two separate natural epidemic foci: the north focus is the Wulanchabu Plateau medium temperature desert steppe and the south focus is ordos Warm-temperate desert steppe. 4 The natural epidemic foci is located from latitude 37°34′N-45°00′N and longitude 106°30′E-114°50′E, as illustrated by Fig. 1.(Eisen et al., 2007c), with an elevation of 1,000-1,600 metres, a stratiform upland plain topography, and a semi-desert landscape. The Chahar hills dry steppe is mainly low mountains and hills, and dotted with marsh land, valley floor and plain in the hills; the area of the natural epidemic focus is 13,4803 km2. It accounts for 10.2 percent of twelve types of natural epidemic foci in China. This is one of the more active natural epidemic foci. There are a total of 29 counties (District, Banner and City). An analysis of the variation in the nest flea indexes has an important value for monitoring and controlling flea epidemics and preventing plague outbreak. 2.2 Data sources and processing methods The data of the epidemic focus of the Meriones unguiculatus administrative map extracted by the Chinese Academy of Sciences Resources and the Environment Scientific Information