Pasture Types and Echinococcus multilocularis, Tibetan Communities

University of Salford, Salford, England, United Kingdom
Emerging infectious diseases (Impact Factor: 6.75). 07/2006; 12(6):1008-10. DOI: 10.3201/eid1206.041229
Source: PubMed


Our study showed that open pastures had more small mammal burrows than fenced pastures in Tibetan pastoralist communities in 2003. This characteristic was linked to a higher prevalence of Echinococcus multilocularis in dogs and indicates that pasture type may affect E. multilocularis transmission.

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Available from: Patrick Giraudoux
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    • "In terms of hygiene, employing ground water as the drinking water source [12,23,31,36] was significantly correlated with CE and/or AE prevalence [36]. Overgrazing [13,26,35,37] and deforestation [10,17] were significant for AE prevalence only. "
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    ABSTRACT: Echinococcosis is a major parasitic zoonosis of public health importance in western China. In 2004, the Chinese Ministry of Health estimated that 380,000 people had the disease in the region. The Qinghai-Tibet Plateau is highly co-endemic with both alveolar echinococcosis (AE) and cystic echinococcosis (CE). In the past years, the Chinese government has been increasing the financial support to control the diseases in this region. Therefore, it is very important to identify the significant risk factors of the diseases by reviewing studies done in the region in the past decade to help policymakers design appropriate control strategies.Review: Selection criteria for which literature to review were firstly defined. Medline, CNKI (China National Knowledge Infrastructure), and Google Scholar were systematically searched for literature published between January 2000 and July 2011. Significant risk factors found by single factor and/or multiple factors analysis were listed, counted, and summarized. Literature was examined to check the comparability of the data; age and sex specific prevalence with same data structures were merged and used for further analysis.A variety of assumed social, economical, behavioral, and ecological risk factors were studied on the Plateau. Those most at risk were Tibetan herdsmen, the old and female in particular. By analyzing merged comparable data, it was found that females had a significant higher prevalence, and a positive linearity relationship existed between echinococcosis prevalence and increasing age. In terms of behavioral risk factors, playing with dogs was mostly correlated with CE and/or AE prevalence. In terms of hygiene, employing ground water as the drinking water source was significantly correlated with CE and AE prevalence. For definitive hosts, dog related factors were most frequently identified with prevalence of CE or/and AE; fox was a potential risk factor for AE prevalence only. Overgrazing and deforestation were significant for AE prevalence only. Tibetan herdsmen communities were at the highest risk of echinococcosis prevalence and should be the focus of echinococcosis control. Deworming both owned and stray dogs should be a major measure for controlling echinococcosis; treatment of wild definitive hosts should also be considered for AE endemic areas. Health education activities should be in concert with the local people's education backgrounds and languages in order to be able to improve behaviors. Further researches are needed to clarify the importance of wild hosts for AE/CE prevalence, the extent and range of the impacts of ecologic changes (overgrazing and deforestation) on the AE prevalence, and risk factors in Tibet.
    Full-text · Article · Jan 2014 · Infectious Diseases of Poverty
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    • "Temperature and relative humidity have an impact on tapeworm egg survival (Veit et al. 1995) and may be important limiting factors at various scales (Burlet et al. 2011). Moreover, correlations between land cover and spatial distribution of human AE have been evidenced in Eastern France, in South Gansu, in South Ningxia and on the Tibetan plateau of western Sichuan and Qinghai (Giraudoux et al. 2003, 2006, 2013; Wang et al. 2004, 2006; Pleydell et al. 2008). A similar correlation has been found for fox infection in France (Pleydell et al. 2004). "
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    ABSTRACT: SUMMARY From continental to regional scales, the zoonosis alveolar echinococcosis (AE) (caused by Echinococcus multilocularis) forms discrete patches of endemicity within which transmission hotspots of much larger prevalence may occur. Since the late 80s, a number of hotspots have been identified in continental Asia, mostly in China, wherein the ecology of intermediate host communities has been described. This is the case in south Gansu, at the eastern border of the Tibetan plateau, in south Ningxia, in the western Tian Shan of Xinjiang, and in the Alay valley of south Kyrgyzstan. Here we present a comparative natural history and characteristics of transmission ecosystems or ecoscapes. On this basis, regional types of transmission and their ecological characteristics have been proposed in a general framework. Combining climatic, land cover and intermediate host species distribution data, we identified and mapped 4 spatially distinct types of transmission ecosystems typified by the presence of one of the following small mammal 'flagship' species: Ellobius tancrei, Ochotona curzoniae, Lasiopodomys brandtii or Eospalax fontanierii. Each transmission ecosystem had its own characteristics which can serve as a reference for further in-depth research in the transmission ecology of E. multilocularis. This approach may be used at fine spatial scales to characterize other poorly known transmission systems of the large Eurasian endemic zone, and help in consideration of surveillance systems and interventions.
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    ABSTRACT: The pore size distribution (PSD) analysis method based on nonlocal density functional theory (DFT) and on molecular simulation is reviewed and compared with classical PSD methods. Applications to carbons and oxides are given. The DFT method offers several advantages over classical methods: (a) a valid and accurate description for small pores; (b) a description of the full adsorption isotherm (not just the capillary condensation pressure), as well as other properties such as heats of adsorption; (c) it can be used for supercritical conditions; (d) it accounts for effects of pore shape; (e) it can be improved in a systematic way, since it rests on fundamental statistical mechanics. A critique of the method as currently applied is also offered. In common with most other PSD methods, the model neglects connectivity and pore blocking, and changes in pore size and geometry with pressure and temperature, and assumes that heterogeneity due to differences in pore shape and surface chemical groups can be approximated by an effective porous material, in which all heterogeneity is due to a distribution in pore sizes. Additional tests, using molecular simulation and experiment, are needed to determine whether these neglected effects exhibit signatures in experimental results that are distinct from the PSD effects. Molecular simulation studies of pore connectivity effects have been made for a simple network model; the model seems able to provide a detailed molecular explanation for the several hysteresis types found in Type IV and V isotherms.
    No preview · Chapter · Jan 1997
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