共查询到19条相似文献,搜索用时 68 毫秒
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研究了一类潜伏期和感染期均有传染力的SEIQR模型,借助于轨道稳定性,Jacobian矩阵等方法,得到了疾病消亡的阈值——基本再生数R_0,通过构造Lyapunov函数,证明了无病平衡点及地方病平衡点的存在性及全局稳定性. 相似文献
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讨论了时变接触率和时变接种率的传染病模型,模型中考虑对易感者和染病者同时接种.通过计算得到了判别疾病流行与否的阈值.证明了当基本再生数小于1时,疾病是流行的;当基本再生数大于1时,疾病将成为地方病. 相似文献
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研究了一类具有隔离仓室和潜伏仓室的非线性高维自治微分系统SEQIJR传染病模型,得到疾病绝灭与否的阀值一基本再生数R0.证明了当R0≤1时,模型仅存在无病平衡点,且无病平衡点是全局渐近稳定的,疾病最终绝灭;当R0〉1时,模型存在两个平衡点,无病平衡点不稳定,地方病平衡点全局渐近稳定,疾病将持续.隔离措施影响着基本再生数,进而推得结论:适当地增大隔离强度,将有益于有效地控制疾病的蔓延.这就从理论上揭示了隔离对疾病控制的积极作用. 相似文献
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本文研究一类与环境有关的SVIBR的传染病模型,得到了基本再生数0R证明了当0R1时无病平衡点全局渐近稳定。 相似文献
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一类具有常数迁入且总入口在变化的SIRI传染病模型的稳定性 总被引:3,自引:0,他引:3
讨论一类具有常数迁入率,染病类有病死且有效接触率依赖于总人数的SIRI传染病模型.给出了基本再生数σ的表达式.如果σ≤1,则疾病消除平衡点是全局稳定的;如果σ>1,则存在唯一的传染病平衡点且是局部渐近稳定的.对具有双线性传染率和标准传染率的相应模型,进一步证明了当σ>1时传染病平衡点的全局稳定性. 相似文献
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An integro-differential equation is proposed to model a general relapse phenomenon in infectious diseases including herpes. The basic reproduction number R(0) for the model is identified and the threshold property of R(0) established. For the case of a constant relapse period (giving a delay differential equation), this is achieved by conducting a linear stability analysis of the model, and employing the Lyapunov-Razumikhin technique and monotone dynamical systems theory for global results. Numerical simulations, with parameters relevant for herpes, are presented to complement the theoretical results, and no evidence of sustained oscillatory solutions is found. 相似文献
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To control emerging infectious diseases like SARS, it is necessary to resort to basic control measures that limit exposures to infectious individuals. These measures include isolating cases at diagnosis, quarantining household members and tracing contacts of diagnosed cases, providing the community with advice on how to reduce exposures, and closing schools. To justify such intervention it is important to understand how well each of these measures helps to limit transmission. In this paper, we determine the effect of a number of different interventions on the effective reproduction number and estimate requirements to achieve elimination of the infectious disease. We find that the strategy of tracing and quarantining contacts of diagnosed cases can be very successful in reducing transmission. 相似文献
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The effective reproduction number of an infection, denoted Re, may be used to monitor the impact of a vaccination programme. If Re is maintained below 1, then sustained endemic transmission of the infection cannot occur. In this paper we discuss methods for estimating Re from serological survey data, allowing for age and individual heterogeneity. We describe semi-parametric and parametric models, and obtain an upper bound on Re when vaccine coverage and efficacy are not known. The methods are illustrated using data on mumps and rubella in England and Wales. 相似文献
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The global dynamics of a time-delayed model with population dispersal between two patches is investigated. For a general class of birth functions, persistence theory is applied to prove that a disease is persistent when the basic reproduction number is greater than one. It is also shown that the disease will die out if the basic reproduction number is less than one, provided that the initial size of the infected population is relatively small. Numerical simulations are presented using some typical birth functions from biological literature to illustrate the main ideas and the relevance of dispersal. 相似文献
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In this paper, an SEIS epidemic model is proposed to study the effect of transport-related infection on the spread and control of infectious disease. New result implies that traveling of the exposed (means exposed but not yet infectious) individuals can bring disease from one region to other regions even if the infectious individuals are inhibited from traveling among regions. It is shown that transportation among regions will change the disease dynamics and break infection out even if infectious diseases will go to extinction in each isolated region without transport-related infection. In addition, our analysis shows that transport-related infection intensifies the disease spread if infectious diseases break out to cause an endemic situation in each region, in the sense of that both the absolute and relative size of patients increase. This suggests that it is very essential to strengthen restrictions of passengers once we know infectious diseases appeared. 相似文献
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临床上,感染性疾病由于诊断不明或诊断时间较长导致严重后果的情况并不罕见。近年来,由于新型病原体感染报道层出不穷,现有病原体出现耐药也十分普遍,导致感染性疾病的诊断和治疗仍是临床上亟待解决的难题。核酸适配体是通过体外反复筛选或指数富集配体系统进化(systematic evolution of ligands by exponential enrichment,SELEX)技术筛选出来的一类具有特异性识别能力的寡核苷酸序列,具有靶向结合目标分子的能力,可用于病原体检测和新型治疗性药物的开发。适配体已在感染性疾病诊治中显现良好的应用前景,进一步推进相关研究有望为感染性疾病的诊治提供新的途径。 相似文献
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Ping Yan 《Journal of theoretical biology》2010,265(2):177-184
This paper develops an impulsive SUI model of human immunodeficiency virus/acquired immunodeficiency syndrome(HIV/AIDS) epidemic for the first time to study the dynamic behavior of this model. The SUI model is described by impulsive partial differential equations. First, the well-posedness of the model is attained by the method of characteristic lines and iterative method. Secondly, the basic reproduction number R0(q,T) of the epidemic which depends on the impulsive HIV-finding period T and the HIV-finding proportion q is obtained by mathematical analysis. Our result shows that HIV/AIDS epidemic can be theoretically eradicated if we can have the suitable HIV-finding proportion q and the impulsive HIV-finding period T such that R0(q,T)<1. We also conjecture that the infection-free periodic solution of the SUI model is unstable when R0(q,T)>1. 相似文献
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随着畜牧业发展、宠物市场增长、气候变化、生态系统破坏以及旅行和商业全球化,人与动物之间的关系在全球范围内持续加强。人类与动物之间的联系不断升级,使得病原体的威胁也不断扩散。关于人兽共患疾病的研究多集中在由动物传染给人类的疾病,如疯牛病、艾滋病、禽流感等。但是微生物的交换是相互的,近年来越来越多的研究表明人类亦会将病原体传播给动物,包括新型冠状病毒、耐甲氧西林金黄色葡萄球菌、甲型流感病毒、隐孢子虫和蛔虫等。因此本文对人类疾病传染给动物的研究作一综述,为人与动物传染病的有效预防与控制提供参考。 相似文献