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1.
牙周病,包括牙龈炎和牙周炎,是人类最常见的感染病之一.严重的牙周炎有可能增加某些系统性疾病的易感性,例如心血管病、糖尿病、早产及肺部感染等.总结有关牙周病感染的性质和病理学方面的资料,可对牙周病感染增加某些系统性疾病的易感性作综合阐述.  相似文献   

2.
通常情况下,一种传染病的爆发往往会引起人们某种行为方式的改变,如减少外出、接种疫苗、注意卫生等,这些行为方式的改变又会对疾病的传播方式和控制效果产生很大影响.为了刻画这类行为方式改变的影响,在本文中提出一个改进的SIRS传播模型:易感染者可以处于两种状态——无保护态(Su)和保护态(Sp).易感染个体根据对疾病风险的估计在无保护态和保护态之间不断切换,从Su到Sp的转移概率随着感染人数的增加而增加,反之,从Sp到Su的转移概率随着感染人数的增加而减小.同时,我们假设个体对风险的估计依赖于他们对疾病风险信息的了解程度.通过Monte-Carlo和MarkovChain方法,发现对传染病风险判断的滞后性会导致传染病的周期爆发.  相似文献   

3.
本文综述了大熊猫的内外科疾病、传染病和寄生虫病的发生、治疗及预防。  相似文献   

4.
查明危害呼和浩特地区地膜栽培中番茄的两种病害;番茄角斑病(Pseudomonas corrugota)和番茄溃疡病(Corynebocterium michigamens pv.michigganense)(Smith)Jensen.).国内文献没有见到对前者病害症状的描述.本文所提供的症状可用于诊断这两种细菌病害.  相似文献   

5.
研究了一个传染病动力学的常微分方程模型,给出了该模型解的整体存在唯一性及非负性。  相似文献   

6.
King AA  Ionides EL  Pascual M  Bouma MJ 《Nature》2008,454(7206):877-880
In many infectious diseases, an unknown fraction of infections produce symptoms mild enough to go unrecorded, a fact that can seriously compromise the interpretation of epidemiological records. This is true for cholera, a pandemic bacterial disease, where estimates of the ratio of asymptomatic to symptomatic infections have ranged from 3 to 100 (refs 1-5). In the absence of direct evidence, understanding of fundamental aspects of cholera transmission, immunology and control has been based on assumptions about this ratio and about the immunological consequences of inapparent infections. Here we show that a model incorporating high asymptomatic ratio and rapidly waning immunity, with infection both from human and environmental sources, explains 50 yr of mortality data from 26 districts of Bengal, the pathogen's endemic home. We find that the asymptomatic ratio in cholera is far higher than had been previously supposed and that the immunity derived from mild infections wanes much more rapidly than earlier analyses have indicated. We find, too, that the environmental reservoir (free-living pathogen) is directly responsible for relatively few infections but that it may be critical to the disease's endemicity. Our results demonstrate that inapparent infections can hold the key to interpreting the patterns of disease outbreaks. New statistical methods, which allow rigorous maximum likelihood inference based on dynamical models incorporating multiple sources and outcomes of infection, seasonality, process noise, hidden variables and measurement error, make it possible to test more precise hypotheses and obtain unexpected results. Our experience suggests that the confrontation of time-series data with mechanistic models is likely to revise our understanding of the ecology of many infectious diseases.  相似文献   

7.
鹅常见病毒性疾病的快速诊断技术的建立及其应用   总被引:4,自引:0,他引:4  
根据3种病原基因组相关基因的序列特征设计了三对PCR引物,用于鹅常见的病毒性疾病包括鹅副粘病毒病、鸭瘟、小鹅瘟的鉴别诊断.三对引物均能从各自的参考毒株扩增出与预计片段大小一致的产物,而对其它的病原的扩增结果均为阴性;应用建立的PCR方法对来自广西不同地方的38份临床可疑病例分别进行诊断,DPV、APMV-1和GPV的检测阳性率分别为66.6%(10/15)、55.6%(15/27)和75%(6/8),二重及三重混合感染的占42.8%(9/21).研究结果表明建立的PCR方法具有快速、敏感、特异的特点,可用于疫病的临床快速鉴别诊断特别是多重感染的诊断以及流行病学的调查研究.  相似文献   

8.
Population biology of infectious diseases: Part I.   总被引:20,自引:0,他引:20  
R M Anderson  R M May 《Nature》1979,280(5721):361-367
If the host population is taken to be a dynamic variable (rather than constant, as conventionally assumed), a wider understanding of the population biology of infectious diseases emerges. In this first part of a two-part article, mathematical models are developed, shown to fit data from laboratory experiments, and used to explore the evolutionary relations among transmission parameters. In the second part of the article, to be published in next week's issue, the models are extended to include indirectly transmitted infections, and the general implications for infectious diseases are considered.  相似文献   

9.
Specific and nonspecific immunisation against parasitic infections   总被引:1,自引:0,他引:1  
F E Cox 《Nature》1978,273(5664):623-626
Parasitic diseases present major problems to man and his domesticated animals but do not respond easily to conventional vaccination procedures. Vaccines including attenuated stains, killed parasites, homogenates and soluble extracts all produce varying degrees of protection but controlled infections and immunisation with heterologous species or nonspecific antigens also induce protective immunity.  相似文献   

10.
Smith DL  Dushoff J  Snow RW  Hay SI 《Nature》2005,438(7067):492-495
Malaria is an important cause of global morbidity and mortality. The fact that some people are bitten more often than others has a large effect on the relationship between risk factors and prevalence of vector-borne diseases. Here we develop a mathematical framework that allows us to estimate the heterogeneity of infection rates from the relationship between rates of infectious bites and community prevalence. We apply this framework to a large, published data set that combines malaria measurements from more than 90 communities. We find strong evidence that heterogeneous biting or heterogeneous susceptibility to infection are important and pervasive factors determining the prevalence of infection: 20% of people receive 80% of all infections. We also find that individual infections last about six months on average, per infectious bite, and children who clear infections are not immune to new infections. The results have important implications for public health interventions: the success of malaria control will depend heavily on whether efforts are targeted at those who are most at risk of infection.  相似文献   

11.
金黄色葡萄球菌是食品、医院内感染以及化妆品领域重要致病菌之一,建立和发展快速检测方法对于预防和控制该菌引起的疾病具有重要意义.对金黄色葡萄球菌的生物学特性、流行病学特征进行了简单介绍,并重点综述了近些年建立的常用金黄色葡萄球菌快速检测方法,分析比较了各检测方法的优缺点.  相似文献   

12.
Emerging fungal threats to animal, plant and ecosystem health   总被引:7,自引:0,他引:7  
The past two decades have seen an increasing number of virulent infectious diseases in natural populations and managed landscapes. In both animals and plants, an unprecedented number of fungal and fungal-like diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species, and are jeopardizing food security. Human activity is intensifying fungal disease dispersal by modifying natural environments and thus creating new opportunities for evolution. We argue that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide.  相似文献   

13.
在传染病模型K-M三假设的基础上,进一步的将整体人群按年龄层次分为两个阶段结构,同时考虑对传染病的积极干预,即将染病人群分为染病未被隔离和染病即被隔离两种状态.研究了具有这两种特征的SIRS传染病模型,证明了该模型解的非负性、有界性和整体存在唯一性.  相似文献   

14.
口腔是一个复杂而完整的微生态系统。生活方式、外源性致病菌等外源因子可扰乱口腔微生物组与其宿主之间的共生关系引发龋齿、牙周炎、牙龈炎、口臭等口腔疾病。益生菌是一类活的并对人类机体局部或全身性健康都具有有益作用的微生物。传统上,益生菌被广泛用于功能性食品、医药保健、饲料等各个领域,最常见的用途是治疗或预防胃肠道感染和疾病,改善肠道健康。近十年,各种研究表明益生菌可通过抑制致病菌生长,改善口腔微生物菌群,调节口腔免疫力等方式对各种口腔疾病产生积极的防治效果。作为一种新兴的机体健康维护概念,维护口腔健康的益生菌及其作用机制日益受到国内外学者的密切关注,综述了口腔益生菌在常见口腔疾病中的潜在作用机制,阐述了利用口腔益生菌在防治口腔疾病时所面临的重要问题,同时在口腔益生菌未来的发展趋势和开发方向等方面剖析如何更好地利用口腔益生菌驱动健康食品产业发展,以期为口腔益生菌的深入研究及其在食品工业中的开发应用提供相应参考。  相似文献   

15.
金黄色葡萄球菌(staphylococcusaureus)是引起皮肤粘膜化脓性感染常见的细菌。传播途径主要为受损皮肤及有裂隙的粘膜或因摄食含有肠毒素的食物和吸入染菌尘埃而致病,引起皮肤软组织感染、肺炎、心内膜炎、脑膜炎、骨髓炎、败血症、肠炎、中毒性休克综合症等。本文概论基层医疗单位金葡菌所致的几种主要感染病症的发病及治疗。  相似文献   

16.
J Nicholas  K R Cameron  R W Honess 《Nature》1992,355(6358):362-365
Herpesvirus saimiri (HVS) is a T-lymphotropic gammaherpesvirus which establishes asymptomatic infections in its natural host the squirrel monkey (Saimiri sciureus), but which causes fatal lymphoproliferative diseases in other New World primates. Sequencing studies show HVS is closely related to the human B-lymphotropic gammaherpesvirus Epstein-Barr virus (EBV). However, despite the general colinearity between the genomes of HVS and EBV, HVS contains genes not found in EBV or in the genomes of any of the other sequenced herpesviruses. We have identified two genes, occurring in a region of divergence between HVS and EBV, that have cellular homologues. One of these, ECRF3, is homologous to the genes encoding the human cytomegalovirus (HCMV) and cellular G protein-coupled receptor family of proteins. The other HVS gene, ECLF2, is homologous to the genes encoding cellular cyclins and to our knowledge is the first reported example of a viral cyclin. The presence of G protein-coupled receptor and cyclin homologues in HVS suggests that these genes may be important in the regulation of viral and cellular processes during productive and/or latent infection of host cells, and in particular may be of relevance in the transformation and rapid proliferation of T cells during HVS infections of hosts susceptible to HVS-induced lymphoproliferative diseases.  相似文献   

17.
目的 :分析和总结铜绿假单胞菌下呼吸道感染的临床特点及抗生素敏感性的分布情况。方法 :对 2 8例铜绿假单胞菌下呼吸道感染的临床资料进行综合分析 ,采用纸片法 (Kirby- Bauer)测定该菌的体外药物敏感性。结果 :2 8例患者均有基础肺部疾病 ,其中以慢性支气管炎最常见。临床上表现为发热、咳嗽、咳痰 ,脑部 X线表现为双肺淡薄、斑片状阻影。药敏试验表明 ,铜绿假单胞菌对头孢他啶、头孢哌酮耐药率增加。结论 :铜绿假单胞菌下呼吸道感染多发生在患有各种基础疾病 ,尤其是肺部疾病患者 ,临床表现无特异性 ,耐药率有增加趋势。  相似文献   

18.
基于元胞自动机带有干预机制的传染病模型   总被引:1,自引:0,他引:1  
在经典SEIR模型的基础上,提出了基于元胞自动机带有干预机制的传染病模型,模拟了在医疗干预下传染病的传播过程,动态刻画了不同时间段疾病的爆发情况,体现了传染病区域性传播的特性以及流动性传染的特点。不同传染病各自传播的特征如周期性传播、消退型传播、爆发等,均能在模拟中体现出来,符合传染病传播的规律。仿真结果表明医疗干预和疫苗等医疗措施对传染病传播起到一定的抑制作用,量化了医疗干预的效果,为采取合理的预防及干预手段提供了量化依据。  相似文献   

19.
新冠肺炎疫情背景下我国富硒产业发展的战略思考   总被引:1,自引:0,他引:1  
唐德剑  夏曾润  贺博  祈蒙 《科技促进发展》2021,17(10):1858-1863
硒是人体必需微量元素,与病毒性疾病发病和传播密切相关。新冠肺炎疫情背景下,硒的提高免疫力、抗病毒作用以及富硒产品、天然富硒地区备受关注。以陕西安康、湖北恩施为例,简要概括了我国富硒产业的发展现状,分析了当前富硒产业面临的政策制度、企业培育、科技支撑、标准体系、产品市场等方面的主要问题,并提出相应的对策建议。  相似文献   

20.
Tuberculoma of the lung is one of manifestations in tuberculosis and usually presents as a solitary pulmonary nodule (SPN). It is difficult to differentiate tuberculoma from SPN by other benign or malignant diseases. At present, the crucial role of video-assisted thoracoscopic surgery (VATS) in diagnosis and treatment of pulmonary diseases has been well acknowledged. Here, we reported 53 patients undergoing VATS resection for tuberculomas in our series. No postoperative mortality was found and only two patients experienced prolonged air-leakage (>7 d) and two had minor wound infections that were recovered after anti-tuberculosis or antibiotic treatment. Anti-tuberculosis chemotherapy from 6 to 12 months was routinely used postoperatively. We conclude that VATS is a satisfactory tool for the diagnosis and treatment of tuberculoma and can also establish a reliable diagnosis for all patients with SPNs.  相似文献   

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