Viruses associated with epidemic hemorrhagic fevers of the Philippines and Thailand

Epidemiologic, clinical, and etiologic studies were carried out on a newly recognized, frequently fatal, pediatric disease syndrome which occurred in urban areas infested with Aedes aegypti mosquitoes. Four types of dengue virus (two of which are new), chikungunya virus, and another virus yet to be identified were isolated from the blood of patients. Dengue viruses, types 2 and 3, were isolated from the mosquitoes. Ample serologic confirmation was obtained of concurrent hemorrhagic fever and infection with one or more of these viruses. Thus, it was discovered that viruses of previously recognized types and of closely related new types apparently have etiologic roles in a new and highly dangerous epidemic disease syndrome.     

Emerging diseases. New arenavirus blamed for recent deaths in California

Researchers say a new virus that appears to cause hemorrhagic fever is endemic--but at very low levels--in the western United States. Last week, the California Department of Health Services announced that a recently discovered virus carried by wood rats and pack rats killed a 14-year-old girl in April; moreover, the department says, there's strong evidence that the virus has caused at least two other deaths within the last 14 months. Experts say there is no cause for alarm, however, as they believe it to be a rare event.     

Korean hemorrhagic fever: propagation of the etiologic agent in a cell line of human origin

The etiologic agent of Korean hemorrhagic fever has been propagated in a human cultured cell line derived from a carcinoma of the lung. The cells, described as type II, alveolar epithelial, support replication of the agent and successive passages. Antigen of the Korean hemorrhagic fever agent is readily detected in infected cells by means of direct or indirect fluorescent antibody techniques. Previous attempts to propagate this agent in vitro had been unsuccessful.     

非洲猪瘟诊断技术发展现状与需求分析

非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(ASF virus,ASFV)引起猪的一种出血性、高度接触性传染病,其临床症状与猪瘟极其相似。该病于2018年8月在我国辽宁省沈阳市首次发生,随后在31个省份爆发,造成直接经济损失达数百亿元。由于目前尚无有效的商品化疫苗,快速、灵敏、简便的诊断技术对于防控和根除该病至关重要。总结了目前应用的ASFV检测技术,比较分析了他们的性能,同时探讨了ASFV诊断技术未来的发展方向及趋势,旨在为我国ASF检测及综合防控提供技术参考。     

Chronic infection of rodents by Machupo virus

Machupo virus, the etiologic agent of human hemorrhagic fever in Bolivia, induced chronic asymptomatic infection in laboratory hamsters and colonized individuals of the peridomestic, wild, South American rodent, Calomys callosus. Viruria was detected for more than 500 and 150 days, respectively, in the two species. Chronic viremia was shown only for Calomys. Virus-neutralizing substances were present in parenterally infected adult animals, but not in animals born to, and in contact with, an infected female. Chronic infection in wild rodents may be an important mechanism in the natural history of Machupo and related virus infections.     

Pathogenesis of dengue: challenges to molecular biology

Dengue viruses occur as four antigenically related but distinct serotypes transmitted to humans by Aedes aegypti mosquitoes. These viruses generally cause a benign syndrome, dengue fever, in the American and African tropics, and a severe syndrome, dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), in Southeast Asian children. This severe syndrome, which recently has also been identified in children infected with the virus in Puerto Rico, is characterized by increased vascular permeability and abnormal hemostasis. It occurs in infants less than 1 year of age born to dengue-immune mothers and in children 1 year and older who are immune to one serotype of dengue virus and are experiencing infection with a second serotype. Dengue viruses replicate in cells of mononuclear phagocyte lineage, and subneutralizing concentrations of dengue antibody enhance dengue virus infection in these cells. This antibody-dependent enhancement of infection regulates dengue disease in human beings, although disease severity may also be controlled genetically, possibly by permitting and restricting the growth of virus in monocytes. Monoclonal antibodies show heterogeneous distribution of antigenic epitopes on dengue viruses. These epitopes serve to regulate disease: when antibodies to shared antigens partially neutralize heterotypic virus, infection and disease are dampened; enhancing antibodies alone result in heightened disease response. Further knowledge of the structure of dengue genomes should permit rapid advances in understanding the pathogenetic mechanisms of dengue.     

猪瘟病毒流行病学、病原致病特性及猪瘟综合防制研究

猪瘟是由猪瘟病毒引起猪的高度致死性、接触性传染病,严重危害全球养猪业的重要传染病,也是我国计划要消灭的重大动物疫病之一。近年流行态势十分复杂,本文就CSF的流行情况、病原致病特征及综合防治技术研究等方面进行全面概述,井为猪瘟的防制提出具体实施方案。     

兔出血症病毒人工感染兔的病理学研究

采用兔出血症病毒贵州分离株人工感染家兔,观察其临床表现、病理形态学及病理组织学变化。结果,临床表现:体温升高、被毛蓬乱、抽搐、呼吸困难等症状;肝,心、脾、肾等实质性器官出血或淤血,其中肝和肾有部分坏死;组织病理变化表现:肝、肾等实质性器官充满红细胞、大量中性粒细胞和淋巴细胞。贵州毒株具有高致病潜力。     

消毒技术在非洲猪瘟防控中的应用现状与问题

非洲猪瘟(ASF)是由非洲猪瘟病毒(ASFV)感染家猪和野猪引起的一种急性出血性烈性传染病.世界动物卫生组织(OIE)将其列为法定必须上报的动物疫病.由于目前还没有针对非洲猪瘟的有效疫苗,我国主要采取检疫、扑杀以及严格的生物安全措施进行防控.消毒是生物安全防控ASF的重要手段.目前针对ASFV的灭活方式多种多样,但其灭...     

Endosomal proteolysis of the Ebola virus glycoprotein is necessary for infection

Ebola virus (EboV) causes rapidly fatal hemorrhagic fever in humans and there is currently no effective treatment. We found that the infection of African green monkey kidney (Vero) cells by vesicular stomatitis viruses bearing the EboV glycoprotein (GP) requires the activity of endosomal cysteine proteases. Using selective protease inhibitors and protease-deficient cell lines, we identified an essential role for cathepsin B (CatB) and an accessory role for cathepsin L (CatL) in EboV GP-dependent entry. Biochemical studies demonstrate that CatB and CatL mediate entry by carrying out proteolysis of the EboV GP subunit GP1 and support a multistep mechanism that explains the relative contributions of these enzymes to infection. CatB and CatB/CatL inhibitors diminish the multiplication of infectious EboV-Zaire in cultured cells and may merit investigation as anti-EboV drugs.     

浅谈犬钩端螺旋体病的诊治

犬钩端螺旋体病是由致病性的钩端螺旋体引起的一种人畜共患病。犬主要表现为出血性黄疸、高热、出血性素质、流产、皮肤坏死和水肿等症状。本病是犬的重要传染病之一,雄犬发病率高于雌犬,幼犬发病率高于老年犬。笔者对临床发生的病例采取综合诊疗措施,共治疗该病犬27只,治愈24只,死亡3只,治愈率为88.89%。     

Lassa virus isolation from Mastomys natalensis rodents during an epidemic in Sierra Leone

Lassa fever is a severe febrile illness of man, first recognized in West Africa in 1969. During an epidemic in Sierra Leone, Lassa virus was isolated for the first time from wild rodents of Mastomys natalensis. A high prevalence of infected Mastomys was found in houses occupied by patients with Lassa fever. The data presented provide the first demonstration of an extra-human cycle of Lassa virus transmission and suggest that rodent control may be an effective method of limiting the disease.     

中国部分地区高致病性猪繁殖与呼吸综合征病毒的分子流行病学研究

 【目的】对来自2006年猪病流行爆发地的组织样品进行多种病毒的检测,确定引起本次流行的致病病原及PRRSV的分子流行病学特征。【方法】利用（RT-）PCR对采集的样品进行PRRSV北美型和欧洲型、猪圆环病毒2型（PCV2）、猪血凝性脑脊髓炎病毒（PHEV）、日本乙型脑炎病毒（JEV）以及瘟病毒的检测,对PRRSV阳性的进行ORF5的序列测定并分析。【结果】检测到16份PRRSV北美型阳性样品,PCV2阳性样品2份,其它病毒均未检到。PRRSV ORF5序列分析表明笔者分离到的PRRSV株可分为2个群。【结论】（1）PRRSV与2006年肆虐中国养猪业的猪病流行有直接关系;（2）2006年PRRSV流行株主要是以JX0612株为代表,但不同遗传特征的PRRSV也在流行。     

广西规模猪场主要疫病的流行病学调查与防治

结合流行病学、临床症状、病理变化,采用PCR技术,对2005年1~6月间广西36个发生疫病的规模猪场提供的肝、脾、淋巴结、脑等84份组织病料进行猪繁殖与呼吸综合症(PRRS)、猪瘟(CSFV)、猪伪狂犬病(PRV)、猪圆环病毒2型(PCV-2)检测。结果,检出PRRS阳性病料37份,阳性率44%,阳性场17个,场阳性率47%;CSFV阳性病料16份,阳性率11.9%,阳性场6个,场阳性率22.2%;PRV阳性病料27份,阳性率32.1%,阳性场12个,场阳性率33.3%;PCV-2阳性病料44份,阳性率52.3%,阳性场21个,场阳性率58.3%。同时还发现组织病料和发病猪场中存在猪繁殖与呼吸综合症、猪瘟、猪伪狂犬病、猪圆环病毒2型不同程度的混合感染现象,其中PRRS、PCV-2混合感染最为严重,样品阳性率33.3%,场阳性率25%。表明广西规模猪场主要疫病十分复杂,混合感染现象比较普遍,对广西养猪业带来巨大威胁,应加强疫病的防控工作。     

Mammalian viruses and Rickettsiae; their purification and recovery by cellulose anion exchange columns has significant implications

Techniques of column chromatography with cellulose ion exchangers have been successfully applied to mammalian viruses and rickettsiae. Recovery of virus is excellent, and appreciable purification in terms of phosphorus and protein removal has been demonstrated. Elution characteristics of poliovirus (types 1, 2, and 3), and Coxsackie A9 virus are similar, whereas those of ECHO-13 and Colorado tick fever differ from them as well as from each other. Elution diagrams of preparations of ECHO-13 and polio 2 viruses grown on P(32)-labeled tissue cultures show a high degree of correlation between the distribution of titratable virus and the distribution of radioactivity. A single adsorption and elution of Q fever or epidemic typhus fever rickettsiae results in a striking degree of purification, as demonstrated by electron micrographs. The chromatographic behavior of the animal viruses and rickettsiae appears to depend more upon the chemical nature of the surfaces of these infectious agents than upon their size. The chromatographic procedure described may prove useful in the preparation of purified, P(32)-labeled, fully infectious animal viruses for further fundamental research. It may also prove useful for the removal of unwanted host materials in the preparation of vaccines.     

浅谈猪场非洲猪瘟的防控策略

非洲猪瘟是由非洲猪瘟病毒引起的一种急性、热性、高度接触性传染病,临床上以高热、食欲不振、皮肤出血、高死亡率为主要症状,病理解剖以各组织器官严重出血特别是脾脏肿大出血为主要特征。由于目前市场上没有有效的非洲猪瘟疫苗可供使用,在防疫上     

Using gamma rays to inactivate African swine fever virus

The results of the study of potential ability of gamma rays (⁶⁰Co, PX-gamma-30) to inactivate African swine fever virus in porcine hyperimmune sera, cell culture, and rawhide obtained from animals with African swine fever are discussed. Upon exposure to gamma rays in the doses varying from 5 kGy to 40 kGy, the virus more readily lost its infectivity than its antigenicity, as was demonstrated by the hemadsorption test, inhibition assay, immunoblotting, immunofluorescence, electron microscopy, and the biological assay involving pigs.     

陕西省部分地区猪瘟流行毒株与疫苗毒株E2基因主要抗原区序列变异分析

研究陕西省猪瘟病毒E2基因主要抗原区变异情况,为猪瘟防控提供依据.用巢式PCR方法对猪瘟疫苗和采自陕西省部分地区的疑似猪瘟病料进行E2基因主要抗原区扩增并测序,将测序结果与HCLV疫苗株和Shimen株E2基因进行序列比对分析.结果表明,23株流行毒株之间的核苷酸同源性在86.0％～100％,氨基酸同源性在87.8％～...     

用酶联免疫吸附试验技术检疫猪瘟

采用酶联免疫吸附试验,确诊甘肃天水一起疫情引起发病的原因为猪瘟病毒。并从猪瘟的流行病学调查、检验诊断等方面进行了系统的论述。     

猪瘟病毒石门株NS4B基因的序列测定及分析

采用ＲＴ－ＰＣＲ技术,利用２对引物,从猪瘟病毒（ＣＳＦＶ）强毒石门株感染的猪血中成功扩增了ＮＳ４Ｂ基因,片段大小分别为７５７ｂｐ和７７４ｂｐ。克隆后经酶切鉴定,自动测序和序列分析,结果显示该基因较为保守,与其他猪瘟病毒毒株均有很高的同源性,与同属的ＢＶＤＶＳＤ－１株和ＮＡＤＬ株也有较高的同源性。