论文部分内容阅读
Background Overgrazing was assumed to increase the population density of small mammals that are the intermediate hosts of Echinococcus multilocularis, the pathogen of alveolar echinococcosis in the Qinghai Tibet Plateau. This research tested the hypothesis that overgrazing might promote Echinococcus multilocularis transmission through increasing populations of small mammal, intermediate hosts in Tibetan pastoral communities.Methods Grazing practices, small mammal indices and dog Echinococcusultilocularis infection data were collected to analyze the relation between overgrazing and Echinococcusultilocularis transmission using nonparetric tests and multiple stepwise logistic regression.Results In the investigated area, raising livestock was a key industry. The communal pastures existed and the available forage was deficient for grazing. Open (common) pastures were overgrazed and had higher burrow density of small mammals compared with neighboring fenced (private) pastures; this high overgrazing pressure on the open pastures measured by neighboring fenced area led to higher burrow density of small mammals in open pastures. The median burrow density of small mammals in open pastures was independently associated with nearby canine Echinococcus multilocularis infection (P=0.003, OR=1.048).Conclusion Overgrazing may promote the transmission of Echinococcus multilocularis through increasing the population density of small mammals.