中文摘要：

利用齐次向量场与其诱导向量场的关系对一类传染病模型进行了进一步研究，讨论了其平衡点的存在性和稳定性，求出了该类传染病持续生存和最终消亡的阈值．

英文摘要：

The use of the relationship between homogeneous vector field and its induced vector field for the further research for the model of a class of infectious diseases, discussed the existence and stability of its equilibrium point, found the kinds of infectious diseases continue to survive and enventually extinction threshold.