2009年北京市老年人甲型H1N1流感流行病学分析

目的 分析2009年北京市老年人感染甲型H1N1流感(甲流)分布特征.方法 采用描述性流行病学研究方法对2009年北京市老年人甲流进行流行特征分析.结果北京市老年人确诊甲流病例321例,确诊发病率为13.2/10万;11、12月份发病最多,占84.7%;地区分布中以近郊区分布最多,占53.0%;通过年龄分布分析发现,85岁以上年龄组发病率最高,为19.2/10万,并随着年龄增长病情有加重趋势(x2=7.24,P＜0.01);病例分型中轻症比例最高,占63.6%,重症和危重症病例占36.4%;轻、重、危重病例之间的体质指数(BMI)差异无统计学意义(x2=8.14,P=0.52);甲流病情有随着基础性疾病加重的趋势,病情程度与基础性疾病的数量有关(x2=123.0,P＜0.01).结论 北京市老年人甲流发病率较高,危重症比例较大,应是重点防控的人群之一.     

北京市2009年甲型H1N1流感患者密切接触者的流行病学特点

目的 了解和掌握甲型H1N1流感患者密切接触者的流行病学特点,为未来流感大流行的防控提供可参考的依据.方法 选择2009年5月16日至9月15日北京发现的613例具有明确密切接触者信息的甲型H1N1流感患者(原发病例)及其密切接触者7099名作为研究对象,根据其流行病学凋查资料和标本资料收集相关信息,对甲型H1N1流感密切接触者的感染情况进行描述性分析.通过χ2检验对不同类型甲型H1N1流感密切接触者的感染情况进行比较分析.结果 613例原发病例中,男348例(56.8%),女265例(43.2%),年龄为1～75岁,中位年龄为20岁.7099名密切接触者中,男3518名(49.6%),女3514名(49.5%),性别不详67名(0.9%),年龄为0～99岁,中位年龄为27岁.甲型H1N1流感原发病例密切接触者的感染率为2.4%(167/7099).随着密切接触者年龄的增长,甲型H1N1流感病毒感染率呈现明显下降的趋势(χ2=27.87,P＜0.001);以不同方式与原发病例接触的密切接触者之间的感染率比较差异有统计学意义(χ2=109.76,P＜0.001).甲型H1N1流感原发病例的密切接触者中,隐性感染病例占14.4%(24/167).对于密切接触者中出现症状的感染者,最早可在发病前4.5 d的咽拭子标本中检测到病毒;病毒传代时间的中位天数为2.4 d.结论 甲型H1N1流感原发病例密切接触者的病毒感染率较低;不同年龄及不同接触方式的密切接触者之间的感染率存在差异;14.4%的甲型H1N1流感病毒感染者为隐性感染;甲型H1N1流感病例有可能在发病前4.5 d即具有传染性.

Abstract：

Objective To examine the epidemiologieal characteristics of infection for close contacts of pandemic(H1N1)2009 and to provide scienlific evidence for preparedness and response for the next pandemic.Methotis A total of 613 index cases with clear information of close contacts and their 7099 close contacts,determined between May 16 and September 15,2009,were inchded in this study.Based on data of epidemioiogical investigation,sampling and test of index cases and close contacts,the characteristics of infection for close contacts were described.Results 56.8%(348/613)of the index cases were male,and 43.2%(265/613)were female,and the median age was 20 years(range:1-75 years).49.6%(3518/7099)of the close contacts were male,and 49.5%(3514/7099)were female,but the sex information of 0.9%(67/7099)could not be recorded.The median age of the close contacts was 27 years(range:0-99 years).2.4%(167/7099)of close contacts were infected.The attack rates decreased with inereasing age of close contacts(χ2=27.87,P＜0.001),and were significantly difierent between various contact patterns of close contact(χ2=109.76,P＜0.001).14.4%of the infected close contacts were asymptomatic.For close contacts with symptomatic infection,vims could be shed 4.5 days before illness onset,and the median generation time was 2.4 days.Conclusion The attack rate of close contacts was very low;and the attack rates were different between various ages and contact patterns of close contacts.In this series 14%of cases with pandemic(H1N1)2009 were asymptomatic.The symptomatic cases might have infectivity 1 day earlier before illness onset.     

14例重症/危重症新型甲型H1N1流感病例临床分析

目的 观察新型甲型H1N1流感(简称甲型流感)重症/危重症病例的临床特点,加深对该病重症/危重症病例特点的认识.方法 对2009年11月24日至2010年1月25日在徐州医学院附属医院收治的14例重症/危重症甲型流感患者的临床资料进行回顾性分析.结果 14例患者中,重症6例,危重症8例;男性2例,女性12例(其中孕妇9...     

上海地区2009年人群甲型流行性感冒病毒抗体水平检测分析

目的 了解上海地区人群季节性H1、H3亚型流感病毒抗体水平及职业人群中H5、H9亚型禽流感抗体的检出情况.方法 应用血凝抑制试验对上海地区2009年与禽类密切接触的职业人群356人以及一般人群332人各年龄组进行H1、H3、H5、H9亚型流感病毒抗体的血清学监测.结果 A/Brisbane/59/2007(H1N1)抗体阳性分布,一般人群有275人,占82.8%,职业人群有263人,占73.9%;A/Brisbane/10/2007(H3N2)抗体阳性,一般人群有168人,占50.6%,职业人群有195人,占54.8%;人群中A/Brisbane/59/2007(H1N1)抗体阳性率明显高于H3,与2008年上海地区流感病原学监测情况相吻合.职业人群与一般人群H5亚型抗体阳性率分别为4.2%(15/356)和0.3%(1/332);H9亚型抗体阳性率分别为34.6%(123/356)和2.4%(8/332).不同年龄组中,6个月～5岁年龄组和≥60岁的老年组A/Brisbane/59/2007(H1N1)、A/Brisbane/10/2007(H3N2)抗体阳性率较低.结论 上海地区人群对H1、H3季节性流感有较强的免疫保护,儿童和老年人群H1、H3季节性流感抗体水平较低.职业人群禽流感病毒H5、H9抗体有明显升高趋势,要加强对职业人群流感样患者病原学和血清流行病学监测.     

甲型H1N1流感家庭内传播影响因素的病例对照研究

目的 探讨影响甲型H1N1流感家庭内传播的危险因素,为制定防控策略提供理论依据.方法按1:2的病例对照研究设计,通过"疾病监测信息报告管理系统"在北京市范围内选择符合条件的出现二代病例的家庭作为病例组,调查该家庭中的首发病例和二代病例;而未出现二代病例的家庭且与病例组中的病例相匹配的家庭作为对照组,调查确诊病例和与确诊病例接触频率最高的一位家庭成员.通过问卷调查,收集家庭成员的基本信息、发病及就诊情况和生活方式等.运用条件logistic回归方法分析家庭内感染甲型H1N1流感的危险因素.结果 单因素条件logistic回归分析结果显示,二代病例的文化程度、家庭人口数、家庭人均居住面积、首发病例就诊时间、最近1个月内是否出现流感样症状、是否与原发病例居住在同一房间、是否开窗通风、是否有勤洗手的习惯以及是否接种甲型H1N1流感疫苗等与感染甲型H1N1流感病毒有关.多因素条件logistic回归分析结果表明,二代病例的文化程度(OR=0.42)、是否与原发病例居住在同一房间(OR=3.29)、是否开窗通风(OR=0.28)、是否有勤洗手的习惯(OR=0.71)及是否接种甲型H1N1流感疫苗(OR=0.05)等因素与感染甲型H1N1流感病毒有关.结论 主动接种甲型H1N1流感疫苗、隔离传染源、定期开窗通风及注重个人卫生是控制甲型H1N1流感家庭内传播的重要手段.

Abstract：

Objective To explore the characteristics of transmission of pandemic influenza A/H1N1, and to analyze the possible factors of influencing transmission in families and to provide scientific evidence for formulating strategies of H1N1 prevention and control. Methods A 1∶ 2 matched case-control study was conducted. The case was defined as a household with 2 or more cases and the control was defined as that with 1 case. Face-to-face interview with questionnaire was used to collect information of work and family life of the study participants. Conditional logistic regression was used to analyze the data. ResultsUnivariate analysis showed that factors such as education level of the secondary case, the number of family members, per capita living space, flu-like symptom, insulation of case, ventilation, hand-washing, and influenza A/H1N1 vaccine immunization were all associated with infection of influenza A/H1N1. Results of multivariate logistic regression analysis showed that variables such as education level of secondary case (OR=0.42), insulation of case(OR=3.29), ventilation, (OR=0.28), hand-washing(OR=0.71), influenza A/H1N1 vaccine immunization (OR=0.05)were all correlated to infection of influenza A/H1N1. Conclusions Factors such as vaccine, insulation, ventilation, and hand-washing can help persons in protection from infection of influenza A/H1N1, suggesting the importance of good hygienic habit and immunization with influenza A/H1N1 vaccine.     

上海地区2009年人群甲型流行性感冒病毒抗体水平检测分析

Objective To know the levels of antibodies against influenza A virus subtypes H1 and H3 of population in Shanghai during 2009, and the detection of antibodies against avian influenza virus subtypes H5 and H9 in population which contacts with avian. Methods The serological survey of the antibodies against influenza A viruses subtypes H1, H3, H5 and H9 in 356 close contacts with avian (professional population) and 332 general subjects (general population) at various age groups were carried out using hemagglutinin inhibit (HI) test. Results The positive rates of antibodies against influenza virus A/Brisbane/59/2007 (H1N1) in general population and professional population were 82.8% (275/332) and 73.9% (263/356), respectively; those of A/Brisbane/10/2007 (H3N2)were 50.6% (168/332) and 54.8% (195/356), respectively. The positive rate of antibodies against influenza virus A/Brisbane/59/2007 (H1N1 )was significantly higher than that of influenza A viruses subtype H3, which was consistent with etiological survey of influenza virus in Shanghai during 2008.The positive rates of antibodies against influenza A virus subtype H5 in professional population and general population were 4.2% (15/356) and 0.3% (1/332), respectively; those of influenza A virus subtype H9 were 34.6% (123/356) and 2.4% (8/332), respectively. The positive rates of antibodies against influenza virus A/Brisbane/59/2007 (H1N1 ) and A/Brisbane/10/2007 (H3N2) in age groups of 6 months-5 years and ≥60 years were lower than other age groups. Conclusions The immune protective response against seasonal influenza A subtype H1 and H3 of population in Shanghai is high,while those of children and the elders were low. The levels of antibodies against influenza A viruses subtype H5 and H9 in professinal population present obviously ascending trend, which indicates that the etiological and serological survey of influenza virus in this population should be enhanced.     

新型甲型H1N1流感聚集性发病患者的临床特点和诊治体会

目的 观察群体发病的新型甲型H1N1流感(简称甲型流感)患者的临床特点,探讨奥司他韦和中药治疗与预后的相关性. 方法 分析2009年6月份、8月份和10月份发生的3起聚集性发病的234例患者的临床资料,比较单纯中药治疗和中药+奥司他韦治疗患者的发热持续时间、临床症状消失时间和住院时间. 结果 年龄、体温、血常规及肝肾功能等基线资料两组分布均衡.发热持续时间中药组与中药+奥司他韦组[(28.9±24.3)和(29.6±13.2)h]比较差异无统计学意义(t=-0.03,P>0.05),临床症状消失时间[(5±2.5)和(5±2.6)d]和住院时间[(7.5 ±2.5)和(7.3±3.2)d],两组比较差异均无统计学意义(t值为0.097和-1.16,P>0.05).将高热患者(体温≥39℃)和中低热患者(体温<39℃)进行分层分析,结果显示在中低热患者中,中药组与中药+奥司他韦组的发热持续时间[(17.3 ±12.9)和(22.0±13.0)h]和症状消失时间[(3.4±1.5)和(3.1±1.8)d]比较,差异无统计学意义(t值为1.03和0.43,P>0.05);在高热患者中,虽然两组的症状消失时间差异无统计学意义(中位数为3.5 d和4 d,Z=0.47,P>0.05),但两组的发热持续时间差异有统计学意义(Z=3.354,P<0.01),中药组发热持续时间(中位数为40.5 h)明显长于中药+奥司他韦组(中位数为22 h). 结论 清热祛瘟中药治疗甲型流感有效,轻症患者可以不用奥司他韦治疗.奥司他韦能缩短高热患者的发热时间,提倡早期应用.     

上海地区2010年冬季甲型H1N1流行性感冒病毒株变异分析

目的 了解上海地区2010年冬季人群甲型H1N1流行性感冒(流感)病毒流行株基因及抗原的变异.方法 采集2010年12月至2011年1月间上海地区哨点医院流感样患者咽拭子标本137份,接种犬肾细胞(MDCK),分离流感病毒,直接免疫荧光法(DIF)鉴定流感病毒型,RT-PCR鉴定甲型H1N1,对部分甲型H1N1流感病毒株进行血凝素(HA)、神经氨酸酶(NA)、病毒聚合酶(PB2)片段全基因测序,分析基因及氨基酸位点变异.结果 共分离到53株人流感病毒,48株为甲型H1N1流感病毒,按简单随机抽样法抽取19株测序.HA进化树分析发现,与2010年6月前分离的甲型H1N1毒株比较,绝大部分不位于同一主干上;HA蛋白的氨基酸位点分析显示,部分毒株在抗原决定位点上发生变异.NA蛋白酶活性中心及周围相关位点氨基酸组成保守,未检测到耐奥司他韦和扎那米韦的变异位点.PB2蛋白第627位和701位点分别是谷氨酸和天冬氨酸,仍是禽源流感病毒特征,但第677位点出现E677G突变.结论 2010年冬季上海地区人群甲型H1N1流感病毒流行株与之前春夏季分离株比较已经有一定变异,出现了一些抗原漂移和在哺乳动物宿主内的适应性进化.     

新型甲型H1N1流感危重症临床分析

目的探讨新型甲型H1N1流感危重症患者的临床特点,加深认识,提高诊治水平。方法回顾性分析2009年11月—2011年2月收治的经临床和实验室确诊的8例新型甲型H1N1流感危重病例的临床资料。结果治愈6例,好转1例,死亡1例。结论青壮年、肥胖、伴基础疾病和妊娠的甲型H1N1流感患者易进展为危重症;早期应用奥司他韦,积极治疗基础疾病,控制细菌、真菌感染和液体出入量,实时机械通气并合理应用激素等综合治疗可改善预后,降低病死率。     

32例无基础疾病者甲型H1N1流感危重症特点分析

目的 了解无基础疾病者感染甲型H1N1流感危重症的临床特点、治疗和转归.方法 观察北京地坛医院2009年10月3日-12月31日收治的32例无基础疾病者感染甲型H1N1流感危重症的临床特点、主要治疗和转归.结果 危重症易发生于65岁以下(96.9％)及肥胖者(71.0％).甲型H1N1流感危重症临床特点为高热(96.9...     

Risk factors of pandemic influenza A/H1N1 in a prospective household cohort in the general population: results from the CoPanFlu‐France cohort

Background

The CoPanFlu-France household cohort was set up in 2009 to identify risk factors of infection by the pandemic A/H1N1 (H1N1pdm09) virus in the general population.

Objectives

To investigate the determinants of infection during the 2010–2011 season, the first complete influenza season of study follow-up for this cohort.

Patients/Methods

Pre- and post-epidemic blood samples were collected for all subjects, and nasal swabs were obtained in all subjects from households where an influenza-like illness was reported. Cases were defined as either a fourfold increase in the serological titer or a laboratory-confirmed H1N1pdm09 on a nasal swab, with either RT-PCR or multiplex PCR. Risk factors for H1N1pdm09 infections were explored, without any pre-specified hypothesis, among 167 individual, collective and environmental covariates via generalized estimating equations modeling. We adopted a multimodel selection procedure to control for model selection uncertainty.

Results

This analysis is based on a sample size of 1121 subjects. The final multivariable model identified one risk factor (history of asthma, OR = 2·17; 95% CI: 1·02–4·62) and three protective factors: pre-epidemic serological titer (OR = 0·51 per doubling of the titer; 95% CI: 0·39–0·67), green tea consumption a minimum of two times a week (OR = 0·39; 95% CI: 0·18–0·84), and proportion of subjects in the household always covering their mouth while coughing/sneezing (OR = 0·93 per 10% increase; 95% CI: 0·86–1·00).

Conclusion

This exploratory study provides further support of previously reported risk factors and highlights the importance of collective protective behaviors in the household. Further analyses will be conducted to explore these findings.     

Epidemiology of influenza A (H1N1)pdm09‐associated deaths in the United States,September–October 2009

Please cite this paper as: Regan et al. (2012) Epidemiology of influenza A (H1N1)pdm09‐associated deaths in the United States, September–October 2009. Influenza and Other Respiratory Viruses 6(601), e169–e177. Background From April to July 2009, the United States experienced a wave of influenza A (H1N1)pdm09 virus (H1N1pdm09) infection. The majority of the deaths during that period occurred in persons <65 years of age with underlying medical conditions. Objective To describe the epidemiology of H1N1pdm09‐associated deaths in the US during the fall of 2009. Methods We collected demographic, medical history, and cause of death information on a nationally representative, stratified random sample of 323 H1N1pdm09‐associated deaths that occurred during September 1–October 31, 2009. Results Data were available for 302/323 (93%) deaths. Most cases (74%) were 18–64 years of age and had ≥1 underlying medical condition (72%). Among cases aged <18 years, 16/43 (37%) had a chronic lung disease, and 15/43 (35%) a neurological disorder; among cases aged ≥18 years, 94/254 (37%) had a chronic lung disease and 84/254 (33%) had a metabolic disorder. The median number of days between symptom onset and death was six among children (range, 1–48) and 12 among adults (range, 0–109). Influenza antiviral agents were prescribed for 187/268 (70%) of cases, but only 48/153 (31%) received treatment within 2 days of illness onset. Conclusions The characteristics of H1N1pdm09 deaths identified during the fall of 2009 were similar to those occurring April–July 2009. While most cases had conditions that were known to increase the risk for severe outcomes and were recommended to receive antiviral therapy, a minority of cases received antivirals early in the course of illness.     

Influenza and risk of later celiac disease: a cohort study of 2.6 million people

Objectives: Influenza has been linked to autoimmune conditions, but its relationship to subsequent celiac disease (CD) is unknown. Our primary aim was to determine the risk of CD after influenza. A secondary analysis examined the risk of CD following pandemic influenza vaccination.

Methods: This nationwide register-based cohort study included 2,637,746 Norwegians (born between 1967–2013) followed during 2006–2014 with information on influenza diagnosed in primary or non-primary care, pandemic vaccination (Pandemrix), and subsequent CD. Cox regression yielded hazard ratios adjusted (HR) for socio-demographic characteristics and earlier healthcare use.

Results: During 13,011,323 person-years of follow-up 7321 individuals were diagnosed with CD (56/100,000 person-years). There were 351,666 individuals diagnosed with influenza, including 82,980 during the 2009–2010 pandemic, and 969,968 individuals were vaccinated. Compared with participants without influenza, who had a CD incidence of 55/100,000 person-years, those diagnosed with seasonal and pandemic influenza had a rate of 68 and 78, per 100,000 person-years, respectively. The HR for CD was 1.29 (95%CI, 1.21–1.38) after seasonal influenza and 1.29 (95%CI, 1.15–1.44) after pandemic influenza; HRs remained significantly increased one year after exposure, when restricted to laboratory-confirmed influenza, and after multivariate adjustments. The reverse association, i.e., risk of influenza after CD, was not significant (HR 1.05; 95%CI, 0.98–1.12). The HR for CD after pandemic vaccination was 1.08 (95%CI, 1.03–1.14).

Conclusion: A positive association with influenza diagnosis is consistent with the hypothesis that infections may play a role in CD development. We could neither confirm a causal association with pandemic vaccination, nor refute entirely a small excess risk.     

Novel Clade 2.3.4.4b Highly Pathogenic Avian Influenza A H5N8 and H5N5 Viruses in Denmark, 2020

Since late 2020, outbreaks of H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4.4b have emerged in Europe. To investigate the evolutionary history of these viruses, we performed genetic characterization on the first HPAI viruses found in Denmark during the autumn of 2020. H5N8 viruses from 14 wild birds and poultry, as well as one H5N5 virus from a wild bird, were characterized by whole genome sequencing and phylogenetic analysis. The Danish H5N8 viruses were found to be genetically similar to each other and to contemporary European clade 2.3.4.4b H5N8 viruses, while the Danish H5N5 virus was shown to be a unique genotype from the H5N5 viruses that circulated at the same time in Russia, Germany, and Belgium. Genetic analyses of one of the H5N8 viruses revealed the presence of a substitution (PB2-M64T) that is highly conserved in human seasonal influenza A viruses. Our analyses showed that the late 2020 clade 2.3.4.4b HPAI H5N8 viruses were most likely new incursions introduced by migrating birds to overwintering sites in Europe, rather than the result of continued circulation of H5N8 viruses from previous introductions to Europe in 2016/2017 and early 2020.     

磷酸奥司他韦治疗甲型H1N1流感临床研究

目的分析奥司他韦在临床治疗甲型H1NI流感患者过程中对病情变化及预后的影响。方法采用回顾性分析方法对我院257例甲型H1N1流感患者的临床资料。结果257例患者根据病情划分为普通型、重症型和危重型3组。三组患者年龄、发热时间和平均住院时间比较,差异有显著性（P〈0．001）,使用奥司他韦治疗的比例分别为20％、28％和81％。在发病48小时内开始奥司他韦治疗患者与发病48小时后开始治疗患者比较,发热持续时问和病毒核酸阳性持续时间比较差异有显著性（P〈0．05）。死亡患者与存活患者开始奥司他韦治疗时间比较明显延迟,两组比较差异有显著性（P〈0．001）。结论发病后48小时以后开始磷酸奥司他韦治疗可能导致发热等症状和病毒核酸阳性持续时间延长,并可能导致病死率增加。     

15例甲型H1N1流感重症病例临床分析

目的总结我院收治甲型H1N1流感重症病例15例的治疗经验。方法 15例甲型H1N1流感重症病例都使用奥司他韦进行治疗,起病4 d以上使用仍然有效。2例使用激素,抗生素使用都是早期、联合、广谱。每天有两名市级专家组成员进行查房,专家值班。结果所有病人经过治疗,病情好转,治愈出院。结论一旦出现流感症状要及时去医院治疗,以免发展成重症病例。重症病例不主张使用激素,抗生素使用要求早期、联合、广谱。每天有专家进行查房。     

Inference of age-dependent case-fatality ratios for seasonal influenza virus subtypes A(H3N2) and A(H1N1)pdm09 and B lineages using data from the Netherlands

Background

Despite the known relatively high disease burden of influenza, data are lacking regarding a critical epidemiological indicator, the case-fatality ratio. Our objective was to infer age-group and influenza (sub)type specific values by combining modelled estimates of symptomatic incidence and influenza-attributable mortality.

Methods

The setting was the Netherlands, 2011/2012 through 2019/2020 seasons. Sentinel surveillance data from general practitioners and laboratory testing were synthesised to supply age-group specific estimates of incidence of symptomatic infection, and ecological additive modelling was used to estimate influenza-attributable deaths. These were combined in an Bayesian inferential framework to estimate case-fatality ratios for influenza A(H3N2), A(H1N1)pdm09 and influenza B, per 5-year age-group.

Results

Case-fatality estimates were highest for influenza A(H3N2) followed by influenza B and then A(H1N1)pdm09 and were highest for the 85+ years age-group, at 4.76% (95% credible interval [CrI]: 4.52–5.01%) for A(H3N2), followed by influenza B at 4.08% (95% CrI: 3.77–4.39%) and A(H1N1)pdm09 at 2.51% (95% CrI: 2.09–2.94%). For 55–59 through 85+ years, the case-fatality risk was estimated to double with every 3.7 years of age.

Conclusions

These estimated case-fatality ratios, per influenza sub(type) and per age-group, constitute valuable information for public health decision-making, for assessing the retrospective and prospective value of preventative interventions such as vaccination and for health economic evaluations.     

应对甲型H1N1流感疫情开展培训的实践与思考

根据2009年甲型H1N1流感防控形势，我院及时开展了防治知识和技能的培训。在培训中把握重点，抓住关键，形式多样，内容丰富，收到了良好效果；同时也体会到加强部门间协作，重视国家有关政策法规的学习，加强住院医师毕业后教育的多学科培训和实践教育都是十分必要的。