人感染H7N9禽流感流行特征与防控策略

2013年3月31日中国大陆出现新型禽流感疫情,此次的H7N9禽流感病毒为全球首次发现的新亚型流感病毒,可能由3种流感病毒重组后产生。截至5月31日,我国内地共报告确诊病例131例,死亡39例。而在上海市报告的33例确诊病例中,29例发病于4月6日上海市关闭活禽交易市场前,其余4例发病于关闭后的第一个潜伏期内。33例病例中60岁以上患者占66.7%(22/33);15例死亡病例中,60岁以上患者占80%(12/15);90.91%(30/33)的病例具有可疑的动物或环境暴露史。此次疫情呈散发,虽然出现了2起家庭聚集性病例,但目前还没有明确的人传人的证据。疫情发生后,上海市人民政府适时启动了流感流行应急预案Ⅲ级响应,通过突发公共卫生事件应急响应、关闭全市活禽交易、健康教育、风险沟通等手段,及时有效地控制了疾病的传播。本文分析这次疫情防控工作的得失并提出建议,供今后的防疫工作借鉴参考。     

人感染H7 N9禽流感3例诊疗分析

目的：：分析确诊人感染H7 N9禽流感3例患者的临床特点,并对治疗方法进行探讨。方法：3例患者均行流行病学调查、实验室检查和胸部CT或X线胸片检查,2例有明确的活禽接触史。确诊后给予氧疗、无创呼吸、有创机械通气、奥司他韦、抗感染药物和免疫球蛋白等治疗。结果：2例救治成功,1例死亡。胸部影像学有2例表现短期进展快的双肺磨玻璃影,发病初均有发热、咳嗽及迅速发展的肺炎,血白细胞明显下降,乳酸脱氢酶、肌酸激酶及D-二聚体升高。结论：人感染H7 N9禽流感临床进展快,以肺部损伤为主,60岁以上及合并有急性呼吸窘迫综合征预后差,发病早期干预预后好。     

H7N9禽流感的病毒特征及其对人类健康的潜在威胁

H7N9病毒是一种来自鸟类的禽流感病毒毒株基因重配的新型病毒。H7N9病毒的血凝素(HA)和神经氨酸酶(NA)在种间传播、病毒复制和致病性等方面起着重要作用。新型H7N9病毒最显著的特征之一是在家禽中无明显致病性,却能感染人类并引起较高的病死率。H7亚型禽流感病毒可有不同的NA亚型,具有较强的兼容性,已引起多次人类的感染事件。可以预见这种影响还将会持续并引起严重的公共卫生问题,必须对此加以高度关注。健全的防控网络的建立有助于最大限度地减少禽流感对人类健康和生命的危害。     

新型甲型H7N9流感病毒血凝素基因进化分析

目的探讨2013年4月流行的新型甲型H7N9禽流感病毒的表面蛋白血凝素(HA)基因的进化,以及氨基酸的变异情况。方法从美国国家生物技术信息中心(NCBI)和全球禽流感基因共享数据库(GISAID)中下载H7N9流感病毒以及有代表性的H7N2、H7N3、H7N7亚型流感病毒的HA基因序列,运用Molecular Evolutionary Genetics Analysis(MEGA)version 5.05软件进行序列分析,用邻接法构建基因进化树;通过氨基酸序列分析HA蛋白受体结合位点、糖基化位点和裂解位点的变化。结果 2013年新型甲型H7N9流感病毒与2011年浙江禽类H7N3流感病毒株(JQ906573.1)的相似性达到95.3%～95.6%;受体结合位点氨基酸发生变异,为Q226L,5个糖基化位点高度保守;HA裂解位点位于aa339和aa340之间,仅有1个碱性氨基酸:R。结论 2013年新型甲型H7N9流感病毒HA基因是由中国禽类H7亚型进化而来,Q226L变异导致的受体结合位点的变化可能是新型流感病毒具有人感染性的原因。     

集束化护理在人感染H7N9禽流感防治呼吸机相关性肺炎的应用

人感染H7N9禽流感是由H7N9亚型禽流感病毒引起的急性呼吸道传染病。甲型流感的H7病毒是一组通常在鸟类中传播的流感病毒。H7N9型禽流感是一种新型禽流感病毒,并且可导致人类感染,于2013年3月31日在中国上海和安徽两地率先报告,在国内流行趋势为散发。H7N9病毒感染后可在早期出现发热等症状。传播途径为经呼吸道传播,直接接触病毒也可被感染。高危人群主为从事禽类养殖、销售、宰杀、加工者,     

新型甲型H7N9流感病毒神经氨酸酶基因进化分析

目的探讨2013年新型甲型H7N9流感病毒神经氨酸酶(NA)基因的进化,及其编码蛋白重要氨基酸位点的变异情况。方法从美国国家生物技术信息中心(NCBI)数据库和全球禽流感基因共享数据库(GISAID)下载不同年代、不同地区甲型流感病毒N9亚型的NA基因序列,利用MEGA 5.05和BioEdit软件对基因的核苷酸序列和氨基酸序列进行分析。结果 2013年新型甲型H7N9流感病毒NA基因与2010年捷克共和国H11N9禽流感病毒的相似性达到96%;新型流感病毒存在5个氨基酸的缺失;其中1株新型病毒可能的酶活性位点发生了变异。结论 2013年新型甲型H7N9流感病毒的NA基因可能是由H11N9进化而来;氨基酸的缺失可能是造成人感染和较高病死率的原因。     

甲型H1N1流感病例513例分析

目的对比分析甲型H1N1流感、季节性流感、普通感冒的临床症状、体征及病程。方法对比分析2009年5-10月来我科就诊并确诊为甲型H1N1流感患者513例（A组）、季节性流感患者242例（B组）、普通感冒患者1200例（C组）的临床资料。结果A、B组患者头痛、咽痛、咳嗽、胃肠症状、全身酸痛、关节痛等症状发生率,最高体温、发热天数、肺部哆音和腹部压痛等体征发生率以及血常规检验中淋巴细胞百分比、单核细胞百分比均明显高于C组,血小板计数明显低于C组,差异均有统计学意义（P〈0．05）;A组患者头痛、咳嗽、胃肠症状等的发生率,扁桃体肿大、肺部哆音、腹部压痛等体征发生率,以及血常规检验中淋巴细胞百分比、单核细胞百分比等均高于B组（P〈0．05）。结论甲型H1N1流感患者症状、体征、病程及血常规检查均较普通感冒重,类似于季节性流感,但二者在某些症状和实验室指标方面有明显差别。     

新型H7N9病毒在同居小鼠中的传播途径

目的 进一步了解新型H7N9流感病毒的致病性、传播能力以及通过何种途径进行传播。方法 H7N9病毒感染小鼠后与同居小鼠合笼,研究同居小鼠的临床变化指征、病毒复制情况、病毒在组织中的分布以及病理变化。以同居小鼠分泌物接种其他小鼠,观察同居小鼠通过何种途径传播病毒。结果 H7N9病毒可以在肺组织、肠组织和脑组织中复制,并可以在同居小鼠中传播。H7N9病毒感染小鼠其咽、眼分泌物以及粪便均具有感染性,其中尤以咽拭子的传播风险最高。结论 H7N9病毒可以不通过适应就感染小鼠,并引起小鼠间传播。被感染小鼠分泌物具有感染性。     

7例重症甲型H1N1流感患儿的监护

本文报告了7例确诊甲型H1N1流感患儿成功救治的护理过程.重点介绍入院时的急救流程、严密的病情观察、人工气道管理、心理护理及消毒隔离措施.本组1例因严重脑干损伤意识未能恢复,其余6例康复出院.     

甲型H1N1流感患者的护理体会

自我市发现第1例甲型H1N1流感以来,我院采取紧急预防,控制措施,全面启动落实医疗救治应急管理体系,做到早发现、早报告、早隔离、早治疗,自2009年5～11月,共收治甲型H1N1确诊患者8例。现将护理体会总结如下。     

Bedside chest radiography of novel influenza A （H7N9） virus infections and follow-up findings after short-time treatment

Background Influenza A （H7Ng） virus infections were first observed in China in March 2013.This type virus can cause severe illness and deaths,the situation raises many urgent questions and global public health concerns.Our purpose was to investigate bedside chest radiography findings for patients with novel influenza A （H7Ng） virus infections and the followup appearances after short-time treatment.Methods Eight hospitalized patients infected with the novel influenza A （H7Ng） virus were included in our study.All of the patients underwent bedside chest radiography after admission,and all had follow-up bedside chest radiography during their first ten days,using AXIOM Aristos MX and/or AMX-Ⅳ portable X-ray units.The exposure dose was generally 90 kV and 5 mAs,and was slightly adjusted according to the weight of the patients.The initial radiography data were evaluated for radiological patterns （ground glass opacity,consolidation,and reticulation）,distribution type （focal,multifocal,and diffuse）,lung zones involved,and appearance at follow-up while the patients underwent therapy.Results All patients presented with bilateral multiple lung involvement.Two patients had bilateral diffuse lesions,three patients had unilateral diffuse lesions of the right lobe with multifocal lesions of the left lobe,and the remaining three had bilateral multifocal lung lesions.The lesions were present throughout bilateral lung zones in three patients,the whole right lung zone in three patients with additional involvement in the left middle and/or lower lung zone（s）,both lower and middle lung zones in one patient,and the right middle and lower in combination with the left lower lung zones in one patient.The most common abnormal radiographic patterns were ground glass opacity （8/8）,and consolidation （8/8）.In three cases examined by CT we also found the pattern of reticulation in combination with CT images.Four patients had bilateral and four had unilateral pleural effusion.After a short period of treatment the pneumonia in one patient had significantly improved and three cases demonstrated disease progression.In four cases the severity of the pneumonia fluctuated.Conclusions In patients with influenza A （H7N9） virus infection,the distribution of the lung lesions are extensive,and the disease usually involves both lung zones.The most common imaging findings are a mixture of ground glass opacity and consolidation.Pleural effusion is common.Most cases have a poor short-time treatment response,and seem to have either rapid progressive radiographic deterioration or fluctuating radiographic changes.Chest radiography is helpful for evaluating patients with severe clinical symptoms and for follow-up evaluation.     

Potential infections of H5N1 and H9N2 avian influenza do exist in Guangdong populations of China

Background Southeast China is one of the sites of influenza origin. During 2003-2004, nine avian influenza outbreaks took place in Guangdong Province. But no human case was reported. To examine the status of potential human infection by human influenza （H1N1, H3N2） and avian influenza （H5N1, H7N7, H9N2） in the avian influenza epidemic area of Guangdong Province, China, we conducted a seroepidemiologic survey in the people of this area from April to June of 2004.
Methods Three out of 9 H5N1 avian influenza affected poultry areas in Guangdong were randomly selected, and the population living within 3 kilometers of the affected poultries were chosen as the survey subjects. One thousand two hundred and fourteen people were selected from 3 villages at random. Human and avian influenza antibody titers were determined by hemagglutination-inhibition （HI） test and microneutralization test （MNT）.
Results The positive rate of antibody to H5N1 was 3.03% in the occupational exposure group and 2.34% in general citizens group; that of H9N2 was 9.52% in the occupational exposure group and 3.76% in the general citizens group. Moreover one case in the occupational exposure group was positive for H7N7. One year later, all previously positive cases had become negative except for one H5N1-positive case.
Conclusion The observations imply that H5N1 and H9N2 avian influenza silent infections exist in Guangdong populations.     

An overview of the recent outbreaks of the avian-origin influenza A (H7N9) virus in the human

Since the first human infection with influenza A (H7N9) viruses have been identified in Shanghai on March 31, 2013, the latest variant of the avian flu virus has spread across four Chinese provinces recently. Human infections with avian influenza are rare and this is the first time that human infection with a low pathogenic avian influenza A virus has been associated with fatal outcome. To date (May 5^th, 2013), China had reported 128 confirmed H7N9 infections in human, among 27 died. Most reported cases have severe respiratory illness resulting in severe pneumonia and in some cases have died. No evidence of sustained human-to -humans at this time, however, there is one family cluster with two confirmed cases for which human-to-human transmission cannot be ruled out. Recent evidence showed that the gene sequences of this novel H7N9 virus is primarily zoonotic and may be better adapted than other avian influenza viruses to infect human. Effective global infection control is urgently needed, and further surveillance and analyses should be undertaken to identify the source and mode of transmission of these viruses.     

认识甲型H7N9禽流感

自2013年3月31日中国疾病预防控制中心首次自3个不明原因肺炎患者标本中分离出甲型H7N9禽流感病毒,并对该病毒进行进一步研究,描述该病毒的基因结构,首次在中国发现并确诊了甲型H7N9禽流感患者。H7N9禽流感对禽类致病性低,而对人类致病性高,目前尚无人间传播的证据。本文就目前对甲型H7N9禽流感的资料进行总结、分析,从临床的角度对甲型H7N9禽流感的病原学、临床及流行病学资料进行整理、分析。     

甲型流感病毒H9N2亚型毒株血凝素基因特性的研究

目的　了解人甲型流感病毒H9N2亚型毒株的来源及从分子生物学角度来弄清不同宿主来源的H9N2亚型毒株间相互关系。方法　病毒在鸡胚中传代 ,从收获的尿囊液中提取病毒粒RNA ,通过逆转录合成cDNA。cDNA通过PCR进行扩增 ,接着PCR产物用纯化试剂盒进行纯化。而后 ,RNA序列测定是采用双脱氧链末端终止和克隆法。最后用MegAlign( 1.0 3版 )和Editseq( 3.69版 )软件进行种系发生学分析。结果　从中国所分离出的H9N2亚型毒株。它们的HA1与HA2间裂解部位的氨基酸序列均为R S S R ,除一株鸽病毒其HA蛋白分子上仅含 7个潜在的糖基化位点外 ,而其余的均含 8个。 6株H9N2毒株HA蛋白分子上氨基酸序列有 2 - 16个不同 ,这些不同分布在 2 4个不同的位点上。近来在中国同时流行着多种HA基因系的H9N2亚型毒株。结论　人甲型流感病毒H9N2亚型毒株可能性最大来自鸡的H9N2毒株 ,而不是来源于鸽的H9N2毒株。但 ,H9N2毒株是否具有人传人能力 ,至今仍不清楚。在中国同时流行着多种HA基因系的H9N2毒株。     

H7N9禽流感病毒在小鼠体内的适应性研究

目的进一步探讨H7N9禽流感病毒对哺乳动物的感染与致病能力,并对其分子机制进行研究。方法以病毒滴鼻感染小鼠,在BALB／c小鼠肺组织中连续传代,通过病毒全基因组测序及比对探寻适应的分子机制。结果禽流感H7N9A／Anhui／1／2013病毒,经过在小鼠体内进行9次传代后,对鼠肺适应株与野生型毒株进行基因比对,发现适应株HA基因,NA基因以及PA亚基共发生了4个有义突变。结论禽流感H7N9A／Anhui／1／2013病毒经连续传代后基因发生突变,但对病毒的毒力以及致病力影响仍需后续实验验证。