A key element in disease emergence/re-emergence is ecosystem disruption as a result of anthropogenic effects which may be rapid as in tropical deforestation or more subtle as in agricultural expansion and overgrazing in temperate biomes. There is however difficulty in developing suitable models to study ecology of infectious diseases, wherein spatial determinants that meaningfully characterize wildlife reservoir habitat, can be linked in turn to host ecology and to dynamics of pathogen/parasite transmission. Using a multidisciplinary approach, grounded on 5 years of collaborative data collected in China from studies on human exposure, transmission ecology, landscape characterization and epidemiology for a pathogenic zoonotic helminth (Echinococcus multilocularis), we aim to develop a general spatio-deterministic model that provides a practical synthesis of host-landscape ecology and transmission models. This approach will be applied study the ecology of transmission of Echinococcus between canids and small mammal reservoir hosts in a geographically defined zone, the Tibetan Plateau (comprising, Sichuan, Qinghai, and Tibet Autonomous Region), and compare wildlife and semi-domestic transmission patterns with that of a geographically separated endemic focus in Central Asia (Xinjiang/Kazahkstan region). A central goal will be to quantify the impact of ecosystem disruption, through livestock over-grazing, socio-economic effects on land-use, and agriculture or deforestation, on the transmission ecology of the parasite, especially in relation to maintenance of enzootic meta-stability at local and regional scales, and to determine relative zoonotic potential. The integrated spatio-deterministic model will be applied at regional scale and tested using simulations that will enable disease (echinococcosis) risk forecasting and development of optimal control/intervention strategies for high risk communities. 2 main hypotheses will be addressed. Firstly, at ecosystem level (the Plateau); parasite transmission may behave as a meta-stable focus despite inherent and peripheral instabilities. Secondly, spatial variables in the form of landscape characteristics can be linked to parasite transmission dynamics using an integrated modeling approach that takes into account multi-level heterogeneity at habitat, host and parasite domains.
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