江苏省2009年3岁以上自然人群新甲型H1N1流感血清流行病学调查

目的 了解江苏省2009年3岁以上自然人群新甲型H1N1流感抗体水平及流行趋势.方法 利用微量半加敏血凝抑制(HI)方法检测江苏省不同时间(2008年11月和2009年7、8、11月)人群新甲型H1N1流感抗体,比较不同时间、人群及地区的新甲型H1N1流感保护性抗体阳性率和抗体几何平均滴度(GMTs).结果 在新甲型H1N1流感输入江苏地区后第一个流行季节内,2009年7、8、11月人群HI保护性抗体阳性率依次为3.46%、7.59%和16.94%,表现出随时间推移而呈总体增长趋势(P=0.000),不同时间点的性别间保护性抗体阳性率的差异无统计学意义(P＞0.05);除2009年11月外,不同性别间的抗体GMT差异均无统计学意义.同一时间点不同年龄组间、同一年龄组的不同时间点间,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).结论 在2009年8月后江苏地区12～17岁人群成为新甲型H1N1流感暴发的主要人群,至2009年11月该人群总体新甲型H1N1流感保护性抗体阳性率仍较低,该病在全省的流行仍将持续一段时间.     

海南省甲型H1N1流感血清流行病学调查

目的了解海南省2009年甲型H1N1流感大流行高峰后期人群感染水平及流行趋势。方法于2009年12月和2010年1-3月共5次在海口市抽取医院门诊患者、血液中心志愿者,利用血凝抑制(HI)方法进行血清标本甲型H1N1流感抗体检测。结果 5次调查的人群抗体阳性率依次为10.50%(40/381)、16.06%(62/386)、31.35%(121/386)、23.16%(91/393)和38.02%(146/384),随时间推移总体呈增长趋势(χ2=81.17,P<0.05);除0～5岁组外,6～17岁、18～55岁及≥56岁组抗体阳性率均随时间推移而上升(χ2=4.22,P>0.05;χ2=21.25,P<0.05;χ2=39.05,P<0.05;χ2=26.85,P<0.05);6～17岁组抗体阳性率5次调查均最高。结论海南省甲型H1N1流感人群免疫水平逐步提高,该疾病在海南省的流行将维持在较低水平;6～17岁人群为主要感染人群。     

职业暴露人群A(H5N1)和甲型H1N1流感血清抗体分析

目的:了解人禽流感A(H5N1)和甲型H1N1流感职业暴露人群中的感染状况。方法:对职业暴露人群进行个案调查,采用血凝抑制法(HI)检测职业暴露人群血清中人禽流感A(H5N1)和甲型H1N1流感抗体。结果:2009年-2010年采集的624份职业暴露人群血清中未检测出人禽流感A(H5N1)抗体,而在2009年采集的血清中有5份检测出甲型H1N1流感抗体,抗体阳性率为1.55%,2010年采集的血清中抗体阳性率为11.96%,其中<29岁阳性率为17.19%,30岁～59岁阳性率为10.87%。结论:职业暴露人群中未检测出A(H5N1)流感抗体,但仍需加强职业暴露人群监测。同时甲型H1N1流感抗体水平较低,缺乏相应的抗体水平保护。     

Immune response of single dose vaccination against 2009 pandemic influenza A (H1N1) in the Taiwanese elderly

We conducted a multi-center, randomized and laboratory-blinded clinical trial with subgroup analyses, involving adults aged greater than 60 years old (range 61–86 years old), to investigate the immunogenicity and the potential factors affecting the immune response of a monovalent, unadjuvanted, inactivated, split-virus vaccine. A total of 107 subjects were randomized to receive 15 and 30 μg of hemagglutinin antigen in a 1:1 ratio. The immunogenicity was detected through hemagglutination inhibition (HAI) test of serum obtained before and 3 weeks after vaccination. By 3 weeks after vaccination, HAI titer ≧1:40 was observed in 75.5% and 81.1% of participants receiving 15 and 30 μg of hemagglutinin antigen, respectively. Positive seroconversion was observed in 71.7% and 81.1% of recipients of the 15 and the 30 μg, respectively. The GMTs increased by a factor of 10.7 and 17.4 in the groups of 15 and 30 μg, respectively. This study indicated that one dose of 15 μg hemagglutinin antigen without adjuvant induced protective immune response in the majority of elderly. Multivariate logistic regression analyses showed that gender, age and diabetes were statistically significant factors affecting the seroprotection rate (p = 0.04, 0.01 and 0.01, respectively) and seroconversion rate (p = 0.01, 0.01 and 0.01, respectively).     

Improved neutralizing antibody response in the second season after a single dose of pandemic (H1N1) 2009 influenza vaccine in HIV-1-positive adults

Neutralizing antibody titers were determined before and after a single dose of pandemic (H1N1) 2009 influenza vaccine in HIV-1-positive Japanese adults in the first season of the pandemic and in those in the second season who had already received the vaccine in the first season. The antibody response rate at 2-month post-vaccination increased significantly from 49.0% (50/102, 95%CI: 39.0-59.1%) in the 2009/2010 season to 66.7% (42/63, 95%CI: 53.7-78.1%) in the 2010/2011 season. Geometric mean antibody titers (fold dilution) at baseline, at 2 months, and at 4 months also increased significantly from 4.4 (95%CI: 3.3-5.7), 19.0 (95%CI: 13.4-26.8) and 13.7 (95%CI: 9.3-20.2), respectively, in the 2009/2010 season to 8.3 (95%CI: 5.8-11.7), 47.0 (95%CI: 32.2-68.6) and 38.2 (95%CI: 23.8-61.4), respectively, in the 2010/2011 season. Although the vaccine response was low in the first season, it was improved in the second season.     

A clinical study to assess the immunogenicity and safety of a monovalent 2009 influenza A (H1N1) vaccine in an area with low-level epidemics of pandemic influenza

We conducted a multi-center, randomized, laboratory-blinded clinical trial in 185 healthy adults (<60 years) and 107 elders (>60 years) to examine the immunogenicity and safety of different doses of an inactivated, monovalent, non-adjuvanted, split vaccine against the 2009 pandemic influenza A (H1N1) virus. The 186 adults were assigned to three treatment groups, i.e., one 15 μg hemagglutination (HA) antigen dose, two 15 μg or 30 μg HA doses in 3 weeks apart, and the 107 elders were treated with two 15 μg or 30 μg doses in 3 weeks apart. Prior to the vaccination, 4.8% subjects had hemagglutination-inhibition (HAI) antibody titers of 1:40 or more. By day 21 post-vaccination of one dose of 15 μg HA, the seroprotective rate was 95.1% and 75.5% in subjects <60 and >65 years of age, respectively; by day 21 post the second 15 μg HA dose, the seroprotective rates were 93.2% and 73.1%, respectively. The seroprotective rates for recipients of 30 μg HA antigen by day 21 were 95.2% for subjects <60 years and 81.1% for subjects >65 years of age, that was boosted to 98.3% and 80.4%, respectively with a second dose of 30 μg HA antigen. No vaccine-related serious adverse events occurred. The data indicated a single 15 μg HA dose of the vaccine induced a protective immune response in most adults, including the elders >60 years of age, and a booster dose at the third week did not render a higher level of antibody response.     

2010年兵团甲型H1N1流感血清学检测结果分析

目的:了解兵团2010年自然人群新甲型H1N1流感抗体水平及流行趋势。方法:利用血凝抑制(HI)试验方法检测兵团不同时间、人群新甲型H1N1流感抗体,比较不同时间、人群的新甲型H1N1流感抗体阳性率。结果:从1月-3月不同时间的检测,甲型H1N1流感抗体阳性率随着时间推移总体呈现下降趋势,依次为16.7%、15.6%、5.0和4.6%,差别有统计学意义。不同年龄组人群的甲型H1N1抗体阳性率差别较大,7岁～17岁年龄组最高(35.0%),不同年龄组抗体阳性率(P)差别有统计学意义。不同年龄组人群接种甲型H1N1疫苗后抗体阳性率差别无统计学意义。结论:兵团有10.2%的人群具有甲型H1N1流感保护性抗体,普通人群中已经建立一定的免疫屏障。7岁～17岁人群是新甲型H1N1流感暴发的主要人群,应重点防控。     

Serologic status for pandemic (H1N1) 2009 virus, Taiwan

We studied preexisting immunity to pandemic (H1N1) 2009 virus in persons in Taiwan. A total of 18 (36%) of 50 elderly adults in Taiwan born before 1935 had protective antibodies against currently circulating pandemic (H1N1) 2009 virus. Seasonal influenza vaccines induced antibodies that did not protect against pandemic (H1N1) 2009 virus.     

社区甲型流感临床特征分析与比较

目的分析和比较社区散发新型甲型H1N1流感和季节性流感临床特征,为临床诊治甲型流感提供参考依据。方法回顾性分析2009年5-10月来医院发热门诊就诊的具有流感样症状的患者,均经实时荧光定量PCR检测。结果在确诊的129例甲型流感患者中,新型甲型H1N1流感65例,占50.4%,季节性甲型流感64例,占49.6%;新型甲型H1N1流感组平均年龄21岁,季节性甲型流感组36岁,两组差异有统计学意义(P<0.01);新型甲型H1N1流感组学生占47例,占72.3%,季节性甲型流感组13例,占20.3%,两组差异有统计学意义(P<0.01);从临床表现比较,除流涕、扁桃体肿大,两组差异有统计学意义(均P<0.01)外;其他差异均无统计学意义。结论医院确诊的甲型流感患者均为轻型;新型甲型H1N1流感以年轻学生为主;两组甲型流感临床特征相似,需经PCR检测确诊分型。     

2009年北京市学生甲型H1N1流感流行特征

目的描述北京市学生甲型H1N1流感感染情况,分析其流行各阶段的特征。方法收集2009年5月11日～12月31日中国疾病预防控制中心(CDC)《疾病监测信息系统》中报告的学生甲型H1N1流感确诊病例个案信息,应用Excel和SPSS统计软件进行分析。结果 2009年5月11日～12月31日,北京市共确诊甲型H1N1流感学生病例6568例,平均年龄(13.7±4.0)岁,小学和初中学生最多,占68.87%。甲型H1N1在学生中的传播过程分为4个时期。5～6月以外籍输入性病例为主,7～8月聚集性疫情由中小学生向大学生扩散,9～10月,日均确诊病例数突增至94.58人/d,城区发病人数是郊区的2.04倍,44.40%的确诊病例为学校聚集性病例,11～12月,日均确诊病例数迅速下降至3.06人/d,进入12月以后维持在较低水平。结论北京市学生甲型H1N1流感流行特征为:低年龄组高发,从低年龄组向高年龄组扩散,城区向郊区扩散和学校聚集性的特点。     

北京市输入性甲型H1N1流感病例的流行规律分析

2009年5月16日北京确诊第一例输入性甲型H1N1流感病例.经评估,从第一例甲型H1N1流感病例报告至9月底报告病例数接近北京市实际病例数,本研究采用此时期的甲型H1N1流感数据进行流行病学特点分析,并对此时期所采取的防控措施效果进行初步评价.     

2009年北京市海淀区聚集性甲型H1N1流感疫情状况

目的 了解北京市海淀区聚集性甲型H1N1流感疫情的总体发病情况,为制定防控措施提供依据.方法 采用描述性流行病学方法,对2009年海淀区聚集性甲型H1N1流感的流行病学特征进行分析.结果 2009年7～12月,海淀区共报告聚集性甲型H1N1流感疫情34起,涉及单位32家,疫情发生单位均为各级、各类学校;涉及病例794例,总体罹患率1.05%.结论 海淀区聚集性甲型H1N1疫情的发生单位集中在学校,应将学校传染病防控作为工作重点,严格落实各项防控措施,有效控制聚集性疫情的发生.     

北京市2009年甲型H1N1流感疫情分析

目的 分析北京市2009年甲型H1N1流感流行病学特征.方法 采用SPSS11.0软件,对北京市2009年甲型H1N1流感确诊病例的流行病学特征进行描述与分析.结果 2009年北京市共确诊甲型H1N1流感10 802例,重症、危重症病例621例,死亡73例,病死率为0.7%(73/10 802);北京市甲型H1N1流感流行过程可分为输入期、传播期、扩散期、稳中有降期等4个阶段;感染者以青少年为主,占47.9%(5169/10 802),男女性别比为1.3:1;职业分布以学生最多,占52.2%(5 639/10 802),重症、危重症病例及死亡病例均以离退人员为多,分别为15.9%(99/621)及23.3%(17/73);10月份达到流行高峰.结论 北京市2009年甲型H1N1流感病例以青少年学生为主,重症、危重症病例及死亡病例均以离退人员为多.     

Severe cases of pandemic (H1N1) 2009 in children, Germany

In a hospital-based observational study in Germany, we investigated children admitted to pediatric intensive care units and deaths caused by confirmed pandemic (H1N1) 2009 to identify risk factors and outcomes in critically ill children. Ninety-three children were eligible for our study, including 9 with hospital-acquired infections. Seventy-five percent had underlying chronic medical conditions; neurodevelopmental disorders were most prevalent (57%). The proportion of patients having ≥1 risk factor increased with age in years (odds ratio 1.21, p = 0.007). Of 15 deaths, 11 occurred in a pediatric intensive care unit (case-fatality rate 12%, 95% confidence interval 6%-21%). Only 9% of the children had been vaccinated against pandemic (H1N1) 2009; all survived. Our results stress the role of underlying risk factors, especially neurodevelopmental disorders, and the need for improving preventive measures to reduce severe disease and adverse outcomes of pandemic (H1N1) 2009 in children.     

Pandemic (H1N1) 2009, Shanghai, China

To understand the clinical and epidemiologic characteristics of pandemic (H1N1) 2009 virus infection, we retrospectively reviewed medical records of 237 patients with laboratory-confirmed cases reported in Shanghai, China, during May–July 2009. Surveillance activities effectively contained the outbreak and provided useful epidemiologic data for future strategies.     

Seasonal and Pandemic A (H1N1) 2009 influenza vaccination coverage and attitudes among health-care workers in a Spanish University Hospital

Influenza vaccination coverage among health-care workers (HCWs) remains the lowest compared with other priority groups for immunization. Little is known about the acceptability and compliance with the pandemic (H1N1) 2009 influenza vaccine among HCWs during the current campaign. Between 23 December 2009 and 13 January 2010, once the workplace vaccination program was over, we conducted a cross-sectional, questionnaire-based survey at the University Hospital 12 de Octubre (Madrid, Spain). Five hundred twenty-seven HCWs were asked about their influenza immunization history during the 2009–2010 season, as well as the reasons for accepting or declining either the seasonal or pandemic vaccines. Multiple logistic-regression analysis was preformed to identify variables associated with immunization acceptance. A total of 262 HCWs (49.7%) reported having received the seasonal vaccine, while only 87 (16.5%) affirmed having received the pandemic influenza (H1N1) 2009 vaccine. “Self-protection” and “protection of the patient” were the most frequently adduced reasons for acceptance of the pandemic vaccination, whereas the existence of “doubts about vaccine efficacy” and “fear of adverse reactions” were the main arguments for refusal. Simultaneous receipt of the seasonal vaccine (odds ratio [OR]: 0.27; 95% confidence interval [95% CI]: 0.14–0.52) and being a staff (OR: 0.08; 95% CI: 0.04–0.19) or a resident physician (OR: 0.16; 95% CI: 0.05–0.50) emerged as independent predictors for pandemic vaccine acceptance, whereas self-reported membership of a priority group was associated with refusal (OR: 5.98; 95% CI: 1.35–26.5). The pandemic (H1N1) 2009 influenza vaccination coverage among the HCWs in our institution was very low (16.5%), suggesting the role of specific attitudinal barriers and misconceptions about immunization in a global pandemic scenario.     

Experimental pandemic (H1N1) 2009 virus infection of cats

To demonstrate that pandemic (H1N1) 2009 virus may cause respiratory disease in cats, we intratracheally infected cats. Diffuse alveolar damage developed. Seroconversion of sentinel cats indicated cat-to-cat virus transmission. Unlike in cats infected with highly pathogenic avian influenza virus (H5N1), extrarespiratory lesions did not develop in cats infected with pandemic (H1N1) 2009 virus.     

北京市甲型H1N1流感病毒病原学监测分析

目的 分析北京市2009年5-12月甲型H1N1流感病毒检测结果,探讨流感大流行时期甲型H1N1流感病原流行病学特征.方法 2009年5月1日至2009年12月27日,共采集101 852份咽拭子样本,北京市传染病网络实验室利用荧光定量PCR方法检测,并做统计分析.结果 101 852份检测样本中,甲型H1N1流感病毒核酸阳性9843份,总阳性率为9.66%,其中5-6月阳性率为2.85%,7-8月阳性率为3.32%,9-10月阳性率为8.35%,11月阳性率为29.67%,12月阳性率为24.33%.可疑病例排查阳性率为8.40%,病例密切接触者阳性率为4.75%,门诊流感样病例(ILI)阳性率为11.46%,聚集性发热病例及其他病例阳性率为7.33%.年龄分布以5～14岁和15～24岁年龄段为主,男女性别构成比为1.5:1.结论 北京市2009年5-11月甲型H1N1流感病毒感染呈持续上升,12月呈下降趋势,具有一定的流行病学特征.