2010—2011年北京市四次甲型H1N1流感病毒抗体水平动态变化分析

目的了解和掌握北京市不同人群对甲型H1N1流感的免疫水平。方法在2010年1月-2011年4月期间,四次采用多阶段分层随机抽样方法,在北京市六个区分年龄组随机选取调查对象进行问卷调查,并采集血清标本进行甲型H1N1流感病毒抗体检测。结果共选取调查对象18264名。5456名（28．9％）调查对象体内甲型H1N1流感病毒抗体为阳性。总体人群甲型H1N1流感抗体滴度主要集中在1：40—1：320,其中抗体滴度为1：40的人数占总体阳性数的比例达41．61％。同一时间点不同年龄组问、同一年龄组的不同时间点间,血凝抑制（HI）保护性抗体阳性率、抗体GMT水平比较的差异均有统计学意义（P〈0．05）。HI保护性抗体阳性率和抗体GMT存在地区差异（P〈0．05）。不同职业人群间HI保护性抗体阳性率和抗体GMT水平比较差异存在统计学意义（P〈0．05）。结论目前北京市人群中已有超过25％的人群具有甲型H1N1流感病毒保护性抗体,甲型H1N1流感疫苗接种与HI抗体阳性存在相关性,普通人群中已经建立了一定的免疫屏障,但抗体滴度水平较低。     

基于空间自相关分析的北京市甲型H1N1流感流行特征研究

目的 探讨2009年北京市甲型H1N1流感发病的地理区域相关性和聚集性,为今后传染病发病的空间自相关性分析提供参考依据.方法 利用OpenGeoDa 1.0.1软件进行空间全局和局部自相关性分析,呈现2009年甲型H1N1流感空间聚集区域.结果 2009年北京市甲型H1N1流感发病分布不是随机的,呈现显著的空间聚集,即...     

时空扫描方法在北京市甲型H1N1流感聚集性探测中的应用

目的 探讨北京市2009年甲型H1N1流感发病时空分布特征,为传染病预防控制提供理论依据.方法 利用SaTScan8.0软件进行时空扫描分析,通过ArcGIS8.3软件呈现甲型H1N1流感时空聚集区域.结果 按照7天、14天、30天,50％的时间周期进行单纯时间扫描分析,结果显示甲型H1N1流感发病在9月4日-12月1...     

应用SEIR模型预测2009年甲型H1N1流感流行趋势

目的 探讨SEIR模型预测甲型H1N1流感流行趋势的功效.方法 利用国庆前北京市流感样病例数、流感样病例中甲型H1N1流感阳性率及二级以上医院流感样病例就诊率等参数估算甲型H1N1流感实际感染人数,基于传染病传播动力学,建立SEIR模型,对国庆后甲型H1N1流感的流行趋势及高峰达到时间进行预测,与甲型H1N1流感病原学...     

广东从化市首起甲型H1N1流感疫情的调查

目的探讨从化市首例甲型H1N1流感病例的发生过程,为制订防控措施提供依据。方法按照2009年卫生部《甲型H1N1流感流行病学调查和暴发疫情处理技术指南（试行）》的要求进行现场流行病学调查。结果病例潜伏期74h,体温37.5℃,无明显呼吸道症状;临床症状较轻;咽拭子样本检测,甲型H1N1流感病毒核酸阳性,确诊为甲型H1N1流感病例;未见续发二代病例。结论本事件为输入性二代病例引发本地感染甲型H1N1流感疫情,感染者在无防护的环境下,接触保留带有甲型H1N1流感病毒的被褥或尘埃后导致感染。     

大学生对甲型H1N1流感的认知和情绪反应及相关行为调查分析

目的 探讨甲型H1N1流感传播期间,大学生的认知、情绪反应及其相关行为.方法 运用问卷调查了200名在较大学生时这一突发性公共卫生事件的认知、情绪和行为反应.结果 甲型H1N1流感可以预防、得了甲型H1N1流感能够康复、了解政府每天公布的甲漉信息是大学生在甲流期间的主要认知表现;面对甲型H1N1流感,绝大多数人感到平静...     

应用CUSUM和EWMA模型探测甲型H1N1流感流行起始的预警研究

目的 探讨累计和( CUSUM)和指数加权移动平均(EWMA)模型探测甲型H1 N1流感流行起始的功效.方法 利用北京市2009年流感样病例监测数据,分别采用CUSUM和EWMA模型对数据进行分析,与流感病原学监测数据进行对比,分析了不同参数组合下2种模型探测甲型H1N1流感流行起始的效果.结果 流感病原学监测显示20...     

清远市部分重点人群甲型H1N1流感疫苗接种意愿调查分析

目的了解清远市中小学生、孕妇等部分重点人群甲型H1N1流感疫苗接种意愿,为甲型H1N1流感防控决策提供科学依据。方法采用横断面调查方法,对中小学生、孕妇等甲型H1N1流感防控重点人群进行调查。结果 67.71%的学生家长认为普通市民有可能患甲流,82.47%的孕妇担心自己及家人患甲流;22.90%的被调查学生和2.06%的被调查孕妇在过去1年里接种过普通流感疫苗;付费情况下,85.45%的学生家长和65.98%的孕妇愿意接种;免费情况下,93.23%的家长和77.32%的孕妇愿意接种。结论被调查居民对甲流关注程度较高,重点人群甲型H1N1流感疫苗接种意愿总体上较强;解决费用问题和消除居民的误解是提高甲流疫苗接种覆盖面的主要途径。     

2009甲型H1N1流感大流行期间北京儿童的流感监测

目的 了解2009年甲型H1N1流感大流行期间北京地区儿童中流感流行的情况.方法 采用WHO推荐的实时荧光定量RT-PCR和国家流感中心推荐的分型方法,对2009年甲型H1N1流感大流行期间因流感样症状来首都儿科研究所附属儿童医院就诊患儿的咽拭子标本进行流感病毒核酸检测.结果 2009年6月1日至2010年2月28日期间共检测了4363份咽拭子标本,其中623例为甲型H1N1阳性,阳性率为14.3%,657例为其他甲型流感病毒阳性(15.1%),所有甲型流感病毒的总阳性率为29.3%.623例中有23例为危重症病例(占阳性患者的3.7%),其中5例死亡.618例信息完整的甲型H1N1病例中,患儿年龄为14天～16岁,性别比例为男比女为1.3:1.1～3岁儿童占25.2%,3～6岁学龄前儿童和6～12岁学龄儿童所占比例相近,各约占30%.在监测期间,仅呈现了一个甲型H1N1的流行波.2009年11月达到最高峰,随后减弱,2010年2月快速下降至2.7%.对监测期间每周20～30份临床标本同时进行季节性流感的监测显示,季节性H3N2、甲型H1N1和乙型流感交替流行.呼吸道合胞病毒(RSV)在甲型H1N1流行趋势减缓后逐渐流行成为流行优势株.结论 2009年6月至2010年2月北京地区儿童中出现甲型H1N1的流行,主要累及学龄前和学龄儿童.季节性流感和RSV与甲型H1N1交替流行.     

招远市中小学生甲型H1N1流感防治知识调查

为提高广大市民对甲型H1N1流感防治知识的了解,我市通过各种途径进行甲型H1N1流感防治知识的宣传。作为脆弱人群的中小学生,更成为我们宣传的重点。为了解招远市中小学生甲型H1N1流感防治知识掌握情况,2009年6月15日至6月24日,招远市疾病预防控制中心开展了中小学生甲型H1N1I流感防治知识调查。     

无锡市流感病毒抗体水平调查

目的调查无锡市人群中甲型、乙型流感病毒抗体水平和新甲型H1N1流感病毒传人前后人群中抗体水平,并对新甲型H1N1流感病毒传人1年后自然人群中成人抗体水平与接种新甲型H1N1流感疫苗后1年的成人抗体水平进行比较。方法收集2008年9月至2009年5月、2010年9月至2011年1月无锡市不同年龄段人群血清和接种新甲型HIN1流感疫苗1年的成人血清,用血凝抑制（HI）试验测定抗体,并比较不同时间段各人群中的流感抗体阳性率、保护率和几何平均滴度（GMT）。结果新甲型H1N1流感病毒传入前,无锡市自然人群的HI抗体阳性率为2．86％（4／140）,保护率为0．71％（1／140）,GMT为5．23。新甲型H1N1流感病毒传入1年后,自然人群的HI抗体阳性率为66．33％,保护率为37．76％、GMT为19．17;其中成人HI抗体阳性率、保护率和GMT分别为50．00％、19．44％和13．09。接种新甲型H1N1流感疫苗的成人1年后HI抗体阳性率、保护率和GMT分别为61．36％、22．73％和14．14,与自然人群中成人在流感病毒传入1年后的抗体水平差异无统计学意义（P均〉0．05）。无锡市人群中甲型与乙型流感病毒HI抗体水平分别为：H1N1病毒抗体阳性率为55．00％,保护率为35．00％,GMT16．90;H3N2抗体阳性率为86．40％,保护率为84．30％,GMT为58．56。结论新甲型H1N1流感病毒传入无锡市1年后,自然人群中新甲型H1N1流感病毒抗体阳性率、保护率和GMT均已达到季节性流感抗体水平。同时人群中已有一定水平的甲型、乙型流感病毒抗体,近期不会发生较大的季节性流感疫情。     

A/PR/8/34(H1N1)病毒株血清流行病学调查

目的了解当今人群中是否仍有Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）这类毒株的活动。方法从全国８个不同地区采集１９７５年之后出生人的血清，用常量半加敏ＨＩ测定Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）毒株的抗体，然后凡ＨＩ效价≥１０的血清，一律按同法对Ａ／Ｓｗｉｎｅ／Ｉｏｗａ／１５／３０（Ｈ１Ｎ１）、Ａ／桂富／１０／１９４（Ｈ１Ｎ１）和Ａ／京防／５３／９７（Ｈ１Ｎ１）毒株进行复核测定。结果有２４份血清ＨＩ效价≥２０，分布于８个不同地区。结论当今我国人群中存在有Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）毒株的活动     

A novel monoclonal antibody effective against lethal challenge with swine-lineage and 2009 pandemic H1N1 influenza viruses in mice

The HA protein of the 2009 pandemic H1N1 viruses (H1N1pdm) is antigenically closely related to the HA of classical North American swine H1N1 influenza viruses (cH1N1). Since 1998, through mutation and reassortment of HA genes from human H3N2 and H1N1 influenza viruses, swine influenza strains are undergoing substantial antigenic drift and shift. In this report we describe the development of a novel monoclonal antibody (S-OIV-3B2) that shows high hemagglutination inhibition (HI) and neutralization titers not only against H1N1pdm, but also against representatives of the α, β, and γ clusters of swine-lineage H1 influenza viruses. Mice that received a single intranasal dose of S-OIV-3B2 were protected against lethal challenge with either H1N1pdm or cH1N1 virus. These studies highlight the potential use of S-OIV-3B2 as effective intranasal prophylactic or therapeutic antiviral treatment for swine-lineage H1 influenza virus infections.     

Profiling of humoral immune responses to influenza viruses by using protein microarray

The emergence of pandemic A(H1N1) 2009 influenza showed the importance of rapid assessment of the degree of immunity in the population, the rate of asymptomatic infection, the spread of infection in households, effects of control measures, and ability of candidate vaccines to produce a response in different age groups. A limitation lies in the available assay repertoire: reference standard methods for measuring antibodies to influenza virus are haemagglutination inhibition (HI) assays and virus neutralization tests. Both assays are difficult to standardize and may be too specific to assess possible partial humoral immunity from previous exposures. Here, we describe the use of antigen-microarrays to measure antibodies to HA1 antigens from seven recent and historical seasonal H1, H2 and H3 influenza viruses, the A(H1N1) 2009 pandemic influenza virus, and three avian influenza viruses. We assessed antibody profiles in 18 adult patients infected with A(H1N1) 2009 influenza virus during the recent pandemic, and 21 children sampled before and after the pandemic, against background reactivity observed in 122 persons sampled in 2008, a season dominated by seasonal A(H1N1) influenza virus. We show that subtype-specific and variant-specific antibody responses can be measured, confirming serological responses measured by HI. Comparison of profiles from persons with similar HI response showed that the magnitude and broadness of response to individual influenza subtype antigens differs greatly between individuals. Clinical and vaccination studies, but also exposure studies, should take these findings into consideration, as they may indicate some level of humoral immunity not measured by HI assays.     

广东省深圳市流感流行特征分析

目的 掌握深圳市流感流行规律,了解甲流大流行以后流感的流行趋势.方法 对深圳市流感样病例监测数据、病原学检测结果和暴发疫情资料进行分析.结果 深圳市的流感样病例百分比(ILI％)为4.67％,呈逐年下降趋势,ILI年龄构成以0-4岁为主(占54.2％).流感病毒分离平均阳性率为10.6％,按月分析流感病毒分离阳性率与ILI％变化趋势呈正相关(r=0.447,P =0.001).全市报告了482起ILI暴发疫情,以乙型流感为主(占63.9％).2010年深圳市季节性流感出现了春季和夏季流行高峰,分别以乙型Victoria系和甲型H1N1亚型为优势株;2011年为冬春季和秋季高峰,以甲型H1N1和季节性H3亚型为优势株;2012年出现了冬春季和夏季高峰,以乙型(Victoria系和Yamagata系)和季节性H3亚型为优势株;2013年出现了春、秋、冬季三个流行高峰,分别以甲型H1N1、季节性H3和乙型Yamagata系为优势株.结论 深圳市季节性流感每年均出现2-3个流行高峰,分别在冬春季和夏秋季,每年流行高峰出现的时间不同,每年流行的型别不同.     

Antibody prevalence to the 2009 pandemic influenza A (H1N1) virus in Germany: geographically variable immunity in winter 2010/2011

Location- and age-specific prevalence of antibodies against 2009 pandemic influenza A (H1N1) virus were determined in sera of blood donors collected during winter 2010/2011 in Germany. Prevalence of antibodies at protective titres (HI ≥1:40) varied significantly between cities (24.13–83.67 %) throughout all age groups. However, high level antibodies (HI >1:80) were most prevalent among young individuals (18–29 and 30–39 years). Overall, this study demonstrates that older people (50–59 and 60–70 years) are no longer more likely to present protective antibody titres against 2009 pandemic influenza A (H1N1) virus than younger individuals. Furthermore, our data show a highly variable immunity among the German population in different major cities almost 2 years after the detection of first cases in Germany.     

Sero‐immunity and serologic response to pandemic influenza A (H1N1) 2009 virus in Hong Kong

To study the serologic response to the new pandemic influenza A (H1N1) 2009 virus in Hong Kong, the level of immunity was measured before and after the occurrence of the outbreak, and the titer of antibody to the pandemic influenza A (H1N1) 2009 virus in serum samples of laboratory confirmed cases. The presence of pre‐outbreak pandemic influenza A (H1N1) 2009 virus antibodies in 37% of individuals older than >65 years suggested previous exposures to heterologous virus strains may have elicited cross‐reacting antibody. Following large outbreaks of pandemic influenza A 2009 virus that peaked in September 2009, there is a change in immunity level in various age groups consistent with the attack rates among population in Hong Kong. Among individuals with mild clinical presentation, the antibody response to pandemic influenza A (H1N1) 2009 virus was stronger in those individuals aged ≤24 years but took more time to reach a titer of 40 when compared with those aged >24 years; however, the antibody level declined slower among individuals aged ≤24 years. Regardless of age, the antibody response rose rapidly and reached much higher titer among individuals with severe clinical presentation. Further study is required to collect additional data on antibody persistence and determine how much protection is conferred by previous exposure to seasonal influenza A (H1N1) viruses. J. Med. Virol. 82:1809–1815, 2010. © 2010 Wiley‐Liss, Inc.     

Comparison of hemagglutination inhibition assay, an ELISA-based micro-neutralization assay and colorimetric microneutralization assay to detect antibody responses to vaccination against influenza A H1N1 2009 virus

The hemagglutination inhibition (HI) assay has been the main method used to investigate immune responses to vaccination against influenza H1N1 (2009) virus. However microneutralization tests (MNT) have been shown to be more sensitive and more specific. In this study, the three methods of choice: (i) the HI assay, (ii) an ELISA-based conventional MNT and (iii) a colorimetric MNT in terms of their ability to detect antibody responses in serum pairs collected from 43 healthy individuals before and 21 days after vaccination were compared. The colorimetric MNT was established yielding intra- and inter-run imprecisions of 7.5% and 12.4%, respectively. Testing of antisera to seasonal influenza viruses demonstrated the assay to be specific for antibodies to influenza H1N1 (2009) virus. A good correlation between the three methods was found, being highest for the ELISA-MNT and the colorimetric MNT (r = 0.714 for geometric mean titers (GMT) and r = 0.695 for titer increases). Similar rates of fourfold titer increases were detected: 95.3% in the ELISA-MNT vs. 93.0% in colorimetric MNT and 95.3% in HI assay. The ELISA-based MNT demonstrated the highest titer range leading to the highest postvaccination GMT and the highest titer increase (>50-fold). The lowest GMTs were measured with the HI assay, while the colormetric MNT detected the highest GMT in prevaccination sera. Taken together, similar seroconversion rates were obtained with the three assays. The ELISA-MNT appeared to be the best method to compare absolute pre- and postvaccination GMTs. The colorimetric MNT, being less labour-intensive than the ELISA-MNT, seems to be a suitable tool in vaccination studies.     

Classical swine H1N1 influenza viruses confer cross protection from swine-origin 2009 pandemic H1N1 influenza virus infection in mice and ferrets

The hemagglutinin of the 2009 pandemic H1N1 influenza virus is a derivative of and is antigenically related to classical swine but not to seasonal human H1N1 viruses. We compared the A/California/7/2009 (CA/7/09) virus recommended by the WHO as the reference virus for vaccine development, with two classical swine influenza viruses A/swine/Iowa/31 (sw/IA/31) and A/New Jersey/8/1976 (NJ/76) to establish the extent of immunologic cross-reactivity and cross-protection in animal models. Primary infection with 2009 pandemic or NJ/76 viruses elicited antibodies against the CA/7/09 virus and provided complete protection from challenge with this virus in ferrets; the response in mice was variable and conferred partial protection. Although ferrets infected with sw/IA/31 virus developed low titers of cross-neutralizing antibody, they were protected from pulmonary replication of the CA/7/09 virus. The data suggest that prior exposure to antigenically related H1N1 viruses of swine-origin provide some protective immunity against the 2009 pandemic H1N1 virus.