2009-2010年茂名市流感监测结果分析

目的 了解茂名市2009-2010年流感流行状况及毒株的型别分布,分析流感流行趋势,为流感防控提供科学依据.方法 收集茂名市哨点医院的流感样病例(ILI)资料、流感疫情资料和病原学监测结果进行分析.结果 2009年报告ILI3693例,ILI%为4.44%.2010年报告ILI1078例,ILI%为0.81%;2009...     

宁都县某中心小学甲型H1N1流感疫情的调查分析

目的分析此次学校甲型H1N1流感疫情的流行病学特征和控制措施,为制订学校甲型H1N1流感的预防控制措施提供依据。方法采用现场流行病学调查方法分析甲型HINl流感疫情的流行病学特征。运用RT—PCR方法检测流感病毒核酸。结果本起疫情历时11d,全校累计发生流感样病例67例,罹患率为5．58％,实验室检查确诊5例,男生、女生性别比为1．31：1,主要临床症状为发热、咳嗽、咽痛、头痛;采集鼻咽拭子5份,均为甲型H1N1流感病毒核酸阳性。结论此为一起由甲型H1N1流感病毒引起的学校流感暴发疫情：流行季节前应开展流感疫苗应急接种,建立完善的联防联控机制。加强宣传培训,落实预防控制措施．是做好学校传染病暴发疫情控制的关键。     

Avian influenza: a review.

PURPOSE: A review of the avian influenza A/H5N1 virus, including human cases, viral transmission, clinical features, vaccines and antivirals, surveillance plans, infection control, and emergency response plans, is presented. SUMMARY: The World Health Organization (WHO) considers the avian influenza A/H5N1 virus a public health risk with pandemic potential. The next human influenza pandemic, if caused by the avian influenza A/H5N1 virus, is estimated to have a potential mortality rate of more than a hundred million. Outbreaks in poultry have been associated with human transmission. WHO has documented 258 confirmed human infections with a mortality rate greater than 50%. Bird-to-human transmission of the avian influenza virus is likely by the oral-fecal route. The most effective defense against an influenza pandemic would be a directed vaccine to elicit a specific immune response toward the strain or strains of the influenza virus. However, until there is an influenza pandemic, there is no evidence that vaccines or antivirals used in the treatment or prevention of such an outbreak would decrease morbidity or mortality. Surveillance of the bird and human populations for the highly pathogenic H5N1 is being conducted. Infection-control measures and an emergency response plan are discussed. CONCLUSION: Avian influenza virus A/H5N1 is a public health threat that has the potential to cause serious illness and death in humans. Understanding its pathology, transmission, clinical features, and pharmacologic treatments and preparing for the prevention and management of its outbreak will help avoid its potentially devastating consequences.     

Serological evidence for influenza virus activity in Nigeria (1985-1987)

A study to determine the activity of influenza virus among the children population was undertaken between 1985 and 1987 in Nigeria. Paired sera were obtained from children presenting with respiratory diseases at the children emergency and outpatient clinics of the University College Hospital, Ibadan. Forty-two paired sera were examined by haemagglutination-inhibition test to determine HI antibody level of the patients to different serotypes of influenza virus. Ninety percent of the children showed serological evidence of previous contact with influenza A virus subtypes while only 24% were positive when tested against influenza B virus. Twenty-two of the 42 children tested seroconverted to influenza A virus strains while only 2 seroconverted to influenza B virus strain used. Out of the 22 children that seroconverted to influenza A virus, 14 were due to H3N2 A/Mississippi 1/85, 4 to H3N2 A/Leningrad 360/86 and 2 each seroconverted to H1N1 A/Chile 1/83 and H1N1 A/Taiwan 1/180. Two other individuals showed serological conversion to either H3N2 A/Mississippi 1/85 and H1N1 A/Chile 1/83 or H3N2 A/Mississippi 1/85 and H1N1 A/Taiwan 1/86. While cases were seen throughout the year during the period under review, more cases occurred during early (April-May) to peak raining season (September) and during harmattan period (November) in Ibadan area where the study was conducted. It is evident from this study that continuous and synchronous circulation of influenza viruses occur in this environment. There is therefore danger of influenza epidemic under depressed immunity and if the virus is introduced into population with low level of immunity in other parts of the country.     

Circulation of influenza virus A(H1N1) in Moldavia (Romania) during 1978-1982

The influenza virus A(H1N1) subtype that reappeared after an absence of 20 years was incriminated as an etiological agent of acute respiratory disease outbreaks in Moldavia (Romania). There were three epidemics in the winter--spring of 1978, 1979, and 1982, that affected mostly school communities and young adults. In 1980-1981 the circulation of A(H1N1) virus was limited. In all the epidemics mentioned the A(H1N1) subtype caused mild influenza cases, with minimal complications and insignificant mortality.     

Primary structure of influenza virus genome regions coding for polypeptides from the major antigenic sites of H3 hemagglutinin

Nucleotide sequences for some regions of the hemagglutinin (HA) gene of influenza virus A/Leningrad/385/80 (H3N2) were analyzed. A double-stranded complementary DNA was synthesized on the influenza genome RNA in the presence of synthetic oligodeoxyribonucleotides A GCAAAAGCAGG and A GTAGAAACAAG and inserted into the Pst I-site of the pBR322 plasmid through G-C-tailing. Nucleotide sequences were determined by a solid phase modification of the Maxam and Gilbert procedure. A comparison of our data with those for influenza virus A/Bangkok/1/79, which is the nearest sequenced prototype of the strain investigated, revealed only two base changes in the variable region of the HA gene. One of them was accompanied by a change in the coded amino acid (Asp53----Tyr) located in the antigenic site E of the HA glycoprotein. There also were some point mutations in the constant region of the gene. The results obtained are discussed in terms of the evolution of "Hong Kong" influenza viruses during their circulation.     

Activity of ultra-low doses of antibodies to gamma-interferon against lethal influenza A(H1N1)2009 virus infection in mice

Background

The influenza A virus is a highly infective agent that causes acute pulmonary diseases. In serious cases, it causes pneumonia which is particularly fatal in patients with cardiopulmonary diseases, obesity, young children and elderly people. The present study shows a protective effect of ultra-low doses of purified antibodies to gamma-interferon (Anaferon for children®, AC®) against lethal influenza virus infection caused by pandemic influenza virus A(H1N1) in mice.

Methods

Balb/c mice were infected with mouse-adapted pandemic influenza virus A/California/07/09 (H1N1)v. Mortality, weight loss, infectious titer of the virus in lungs and lung morphology were monitored in the groups of AC®-, oseltamivir- and placebo-treated animals.

Results

The protective action of AC® was demonstrated by prolongation of life of the infected animals, reduction of infectious titer of the virus in the lung tissue, normalization of weight dynamics in the course of disease, decrease in mortality of treated animals compared to a placebo control and normalization of lung tissue structure. The protective activity of AC® was similar to that of the reference compound oseltamivir. Combination of AC® with oseltamivir resulted in a higher protective effect comparing to oseltamivir alone.

Conclusion

Based on the results obtained, AC® should be considered as an important part of anti-influenza prophylaxis and therapy, in particular in severe cases of the disease.     

高州市某农村小学乙型流感聚集性疫情调查分析

目的 分析2012年高州市某农村小学聚集性乙型流行性感冒疫情发生的原因及传染来源,为防治流行性感冒提供科学依据.方法 利用流行性感冒的个案调查表、实验室检测结果、现场卫生学资料进行流行病学分析.结果 本次聚集性疫情的发生始于2012年2月18日,首发病例的传染来源不明,最后1例病例发病时间为2月21日,暴露人口263人,发病9例,罹患率为3.4％,无死亡病例.发病年龄分布在13～14岁年龄组,无性别差异,由于首发病例为住宿生,住宿生发病率远高于走读生.采集9例病例血清标本,6例乙型流行性感冒病毒核酸检测阳性.结论 这是一起乙型流行性感冒的聚集性疫情,传播途径为空气飞沫传播;早发现、早报告、早隔离和接种流行性感冒疫苗是控制流行性感冒疫情最为关键的措施.     

The circulation of influenza virus in human communities subjected to the action of noxious chemical substances

Investigations were conducted during 1985 and 1986 years on the effect of some noxious chemicals on the influenza virus circulation in an industrial enterprise community. The presence of influenza virus type A (H1N1), A (H3N2) and B was revealed by immunofluorescence in exfoliated cells collected from nasopharynx. The kinetic of type specific hemagglutination inhibiting antibodies was followed monthly. Chick embryos were used to isolate influenza virus strains. Meaning of the results is discussed from an epidemiological point of view.     

Type II transmembrane serine proteases as potential target for anti-influenza drug discovery

Introduction: The outbreak of an influenza pandemic as well as the continued circulation of seasonal influenza highlights the need for effective antiviral therapies. The emergence of drug-resistant strains further necessitates the development of novel antivirals that target the host factors crucial for viral replication.

Area covered: This review summarizes the current understanding of the structural and functional properties of type II transmembrane serine proteases (TTSPs) as a proteolytic activator of influenza virus infection and discusses their potential as antiviral targets. It also explores the experimental evidence accumulated for inhibitors of TTSPs as novel, broad-spectrum antivirals against various influenza virus subtypes. The review also provides an overview of the properties of small molecules, proteins, and peptides that efficiently inhibit the proteolytic activation of the influenza virus.

Expert opinion: TTSPs activate a wide range of influenza virus subtypes including avian influenza viruses, both in vitro and in vivo, via proteolytic cleavage of influenza hemagglutinin (HA) into infection-competent fusogenic conformation. Other viruses such as SARS-, MERS-coronaviruses and human metapneumoviruses may use the same host cell proteases for activation, implying that TTSP inhibition might be a novel strategy for developing broad-spectrum antiviral agents for respiratory viral infections.     

Upper respiratory tract epithelial cells as a component of local immunity against influenza

A conjugate of influenza virus and erythrocytes was used to detect and quantitatively determine the occurrence of respiratory epithelial cells carrying surface-associated antibody. The method was specific since uncoated erythrocytes, or erythrocytes coated with heterologous virus failed to attach.Epithelial cells carrying surface-bound anti-influenza virus antibodies (Ab) were found in the upper respiratory tract of 23 influenza patients and 117 healthy persons during and after an influenza A(H1N1) outbreak, and in 13 volunteers immunized with killed influenza A(H1N1) vaccine. Furthermore, the appearance of Ab-carrying cells correlated with that of circulating and secretory Ab in washings from the same individuals. The results suggest that the respiratory epithelial cells play an important role in the development and function of local anti-influenza immunity.     

Anti-influenza virus activity of peramivir in mice with single intramuscular injection

In the event of an influenza outbreak, antivirals including the neuraminidase (NA) inhibitors, peramivir, oseltamivir, and zanamivir may provide valuable benefit when vaccine production is delayed, limited, or cannot be used. Here we demonstrate the efficacy of a single intramuscular injection of peramivir in the mouse influenza model. Peramivir potently inhibits the neuraminidase enzyme N9 from H1N9 virus in vitro with a 50% inhibitory concentration (IC(50)) of 1.3+/-0.4 nM. On-site dissociation studies indicate that peramivir remains tightly bound to N9 NA (t(1/2)>24h), whereas, zanamivir and oseltamivir carboxylate dissociated rapidly from the enzyme (t(1/2)=1.25 h). A single intramuscular injection of peramivir (10mg/kg) significantly reduces weight loss and mortality in mice infected with influenza A/H1N1, while oseltamivir demonstrates no efficacy by the same treatment regimen. This may be due to tight binding of peramivir to the N1 NA enzymes similar to that observed for N9 enzyme. Additional efficacy studies indicate that a single injection of peramivir (2-20mg/kg) was comparable to a q.d.x 5 day course of orally administered oseltamivir (2-20mg/kg/day) in preventing lethality in H3N2 and H1N1 influenza models. A single intramuscular injection of peramivir may successfully treat influenza infections and provide an alternate option to oseltamivir during an influenza outbreak.     

甲型流感病毒血凝素基因变异与抗原变异关系研究

目的 了解甲型流感病毒流行株的血凝素基因变异和抗原变异及两者间的关系,结合流行病学资料分析基因变异和抗原变异的吻合情况.方法 从2005-2007年上海市季节性流感样病例分离到的甲型流感病毒株中,选取H1N1、H3N2两个亚型中部分有代表性的病毒株,并同WHO北半球流感疫苗推荐株一起,进行血凝素全基因序列测定后做基因进化树分析.同时用灭活的全病毒抗原免疫金黄地鼠,通过血凝抑制试验测定病毒的血凝效价,对血凝抑制结果进行聚类分析,绘制病毒的抗原变异图.结果 H3N2分离株与WHO北半球疫苗推荐株A/Sydney/5/97、A/Fujian/411/2002处于不同的基因进化分枝上,时间间隔越久,进化距离越远,同样的结果也出现在抗原变异分析中.而H1N1分离株的基因变异情况和抗原变异情况则不一致,在基因变异中,与疫苗推荐株A/New Caledonia/20/1999的距离远近受到分离时间的影响,抗原变异还与病毒是否从散发病例或聚集性病例分离有关.结论 流感病毒血凝素的基因变异和抗原变异的结果基本吻合,采用流行株免疫血清的血凝抑制试验能更好地反映病毒的变异和进化情况.     

甲型流感病毒血凝素基因变异与抗原变异关系研究

目的 了解甲型流感病毒流行株的血凝素基因变异和抗原变异及两者间的关系,结合流行病学资料分析基因变异和抗原变异的吻合情况.方法 从2005-2007年上海市季节性流感样病例分离到的甲型流感病毒株中,选取H1N1、H3N2两个亚型中部分有代表性的病毒株,并同WHO北半球流感疫苗推荐株一起,进行血凝素全基因序列测定后做基因进化树分析.同时用灭活的全病毒抗原免疫金黄地鼠,通过血凝抑制试验测定病毒的血凝效价,对血凝抑制结果进行聚类分析,绘制病毒的抗原变异图.结果 H3N2分离株与WHO北半球疫苗推荐株A/Sydney/5/97、A/Fujian/411/2002处于不同的基因进化分枝上,时间间隔越久,进化距离越远,同样的结果也出现在抗原变异分析中.而H1N1分离株的基因变异情况和抗原变异情况则不一致,在基因变异中,与疫苗推荐株A/New Caledonia/20/1999的距离远近受到分离时间的影响,抗原变异还与病毒是否从散发病例或聚集性病例分离有关.结论 流感病毒血凝素的基因变异和抗原变异的结果基本吻合,采用流行株免疫血清的血凝抑制试验能更好地反映病毒的变异和进化情况.     

Phenolic Diterpenoid Derivatives as Anti-Influenza A Virus Agents

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A/H5N1 prepandemic influenza vaccine (whole virion, vero cell-derived, inactivated) [Vepacel®

The influenza A subtype H5N1 virus is a likely causative agent for the next human influenza pandemic. Pandemic influenza vaccine production can begin only after a novel pandemic virus emerges. Cell-based vaccine production has advantages over conventional egg-based methods, allowing more rapid large-scale vaccine production. A reliable Vero cell culture system is available for pandemic and prepandemic influenza vaccine production. Prepandemic influenza vaccines are an important component of influenza pandemic preparedness plans, as their targeted use in the pandemic alert period or early in a pandemic is likely to mitigate the consequences of an influenza outbreak. Vepacel? is a prepandemic influenza vaccine (whole virion, Vero cell-derived, inactivated) containing antigen of H5N1 strain A/Vietnam/1203/2004 and is approved for use in the EU. Clinical immunogenicity studies with the vaccine have demonstrated good rates of functional neutralizing antibody responses against the vaccine strain (A/Vietnam/1203/2004), meeting established immunogenicity criteria for seasonal influenza vaccines, and cross-reactivity against H5N1 strains from other clades. In phase I/II and III studies, a heterologous (A/Indonesia/05/2005) booster vaccine administered to healthy adult and elderly volunteers 6-24 months after the two-dose priming vaccine (A/Vietnam/1203/2004) regimen induced good immunogenic responses against both H5N1 strains, demonstrating strong immunological memory. Broadly similar, albeit less robust, responses were observed in two special risk cohorts of immunocompromised and chronically ill patients. In general, adverse events observed in clinical immunogenicity studies with H5N1 vaccine (A/Vietnam/1203/2004) were similar to those reported with non-adjuvanted, inactivated, seasonal influenza vaccines.     

2014～2015年南充市禽流感职业暴露人群及环境监测结果分析

目的 了解南充市禽流感职业暴露人群H5N1感染及环境禽流感病毒污染状况.方法 2014～2015年采集南充市禽类职业暴露人群血清标本,用红细胞凝集抑制试验(HI)检测H5N1抗体;对城乡活禽市场、家禽规模养殖、野鸟禽鸟栖息地以及禽类宰杀市场等场所的笼子、粪便以及污水标本采用实时荧光定量PCR法检测禽流感病毒(甲型流感病毒,即FluA)核酸.结果 共采集职业暴露人群160份血清标本,H5N1抗体结果均为阴性采集环境标本160份进行禽流感病毒核酸检测,FluA核酸阳性31份,总检出率为16.32％.其中H5、H7、H9核酸阳性分别是18份、0份、10份,H5、H7、H9检出率分别是9.47％、0％、5.26％,FluA核酸阳性未分型3份,未分型检出率为1.58％,不同类型标本、不同监测点环境、不同监测场所及不同季节监测结果比较差异有统计学意义(x2值分别是37.43、8.67、30.57和30.44,P＜0.05).结论 禽流感H5亚型在南充市职业暴露人群中未发现隐性感染,南充市各类型标本、各监测场所、各监测点环境及各季节均存在禽流感病毒,建议各相关政府部门加强对禽流感相关知识的宣传,加强交易以及宰杀市场等的监管,加强对外环境的监测,必要时采取短期关闭活禽交易、禽类宰杀市场,季节性休市等措施,降低禽流感病毒感染的风险.     

抗流感病毒药物神经氨酸酶抑制剂奥司他韦研究进展

高致病性禽流感H5N1病毒在亚州的爆发和2009新型H1N1病毒的全球性传播,提示设计与研发新型的抗流感药物尤为迫切。神经氨酸酶在病毒复制和传播中发挥重要作用,且活性中心高度保守,其抑制剂成为抗流感药物研发的热点。该文回顾了临床广泛使用的奥司他韦（osehamivir）药动学、药效学及耐药性方面的研究进展,为此药今后的临床应用提出建议。     

Influenza epidemiologic and virologic surveillance in Antananarivo from 1995 to 2002

The "Institut Pasteur de Madagascar" virology laboratory is the National WHO Centre for Influenza surveillance in Madagascar. On this surveillance collaborate the Ministry of Health with 9 sentinel centres. In the present article, the authors relate the results of influenza surveillance in Antananarivo between 1995 and 2002. Among 6341 patients with nasal and/or pharyngeal swabs, influenza virus were isolated from 427 patients (6.7%): 307 (68.4%) influenza virus A (H3N2), 124 (27.1%) influenza virus B, 8 (4.0%) influenza virus A (H1N1). The virus had been continually spreading all year long. The weak and the strong points of the influenza sentinel surveillance are also discussed in order to ameliorate the collection processes of influenzal and respiratory morbidity data.     

甲型H1N1流感合并肺炎支原体感染的病原学分析

目的研究新型甲型H1N1流感患者合并肺炎支原体感染情况。方法收集医院发热门诊及学校集中发热人群的咽拭子标本,荧光PCR法检测其甲型H1N1流感病毒RNA,同时接种肺炎支原体培养液。结果 627份样本中有318例为甲型H1N1流感病毒RNA阳性,占50.7%,在这318例甲型H1N1流感病毒RNA阳性标本中,有61例合并肺炎支原体感染,占甲流患者的19.2%。结论在许昌地区2009年的甲流疫情中,甲流患者合并肺炎支原体感染的情况值得关注,治疗中要注意检测并加用治疗肺炎支原体感染的药物。