重症甲型H1N1流感八例呼吸系统病理学特征分析

目的 探讨重症甲型H1N1流感死亡患者呼吸系统病理变化特征.方法 收集北京市8例重症甲型H1N1流感死亡病例,其中6例为死后床旁穿刺标本,2例为系统尸体解剖标本,进行常规病理形态学观察,并利用免疫组织化学、流式细胞术、Western blot等技术进行病毒定位检测.结果 重症甲型H1N1流感患者呼吸系统的主要病理改变为坏死性支气管炎伴周围炎、弥漫性肺泡损伤、肺出血.Westem blot检测肺组织内可见病毒抗原的表达,免疫组织化学染色显示甲型H1N1病毒核蛋白、血凝素抗原主要表达于部分气管、细支气管上皮及腺体、肺泡上皮细胞、巨噬细胞、血管内皮细胞等.流式细胞术检测2例尸体解剖病例肺内Ⅱ型肺泡上皮凋亡率(32.15％,78.15％)明显高于对照组(1.93％,3.77％).结论 弥漫性肺泡损伤、肺出血和晚期的肺纤维化是甲型H1N1流感重症死亡的主要病理改变;肺脏的损伤可能与病毒侵袭有关.     

白细胞介素1α基因单核苷酸多态性与甲型H1N1流感易感性的关系

目的 探讨白细胞介素1d(IL-1α)基因单核苷酸多态性(SNP)与甲型H1N1流感易感性的关系.方法 从IL-1α基因启动子区域中选取4个SNP位点rs1800587、rs2856836、rs2856838、rs3783525,针对以上位点建立基于飞行时间质谱分析技术(TOF-MS)鉴定SNP的方法,对167例H1N1流感患者(H1N1组)和192例健康对照人群(对照组)进行检测.确定各SNP位点的等位基因和基因分型;对比两组等位基因和各基因型的频率.结果 rs1800587、rs2856836、rs2856838位点具有T和C两种等位基因,包括TT、TC、CC 3种基因型.rs3783525具有A和T两种等位基因,包括AA、AT和TT3种基因型.H1N1组和对照组rs 1800587位点的等位基因频率差异有统计学意义(x2=12.69,P=0.000,OR=2.424,95％CI=1.472 ～ 3.993),rs2856836,rs2856838,rs3783525等位基因频率在H1N1组和对照组中差异则无统计学意义.H1N1组rs1800587位点CC纯合子频率低于对照组[72.5％(121/167)比87.0％(167/192),P＜0.05],杂合子(TC)频率高于对照组[25.1％(42/167)比12.5％(24/192),P＜0.05],而两组TT纯合子频率差异则不具有统计学意义.H1N1组rs2856836位点杂合子(TC)频率高于对照组[25.7％(43/167)比17.2％(33/192),P＜0.05],TT基因型与CC基因型频率在两组间差异均没有统计学意义.rs2856838位点对照组TT纯合子频率低于H1N1组[4.2％(8/192)比10.8％(18/167),P＜0.05],其余2种基因型TC与CC在两组间差异没有统计学意义.H1N1组rs3783525位点TTT纯合子频率高于对照组[21.0％ (35/167)比13.0％(25/192),P＜0.05],两组间的另两种基因型TC与CC差异也没有统计学意义.结论 IL-1α基因多态性位点rs1800587、rs2856836、rs2856838、rs3783525与甲型H1N1流感易感性相关.     

甲型H1N1流感患者排毒规律及抗病毒治疗研究

目的 研究2009年深圳市收治的甲型H1N1流感确诊病例排毒规律和抗病毒治疗疗效.方法 75例患者均经两次鼻咽拭子甲型H1N1流感病毒核酸检测阳性（RT-PCR）,此后每天检测病毒核酸直至连续两天均阴性.第1次病毒检测阳性后立即随机分三组抗病毒治疗,分别为奥司他韦（Oseltamivir）（组Ⅰ）、中药（组Ⅱ）和奥司他韦联合中药（组Ⅲ）抗病毒治疗,5 d为一疗程.应用流式细胞仪检测T细胞亚群和IL-17表达.结果 75例患者中,78.7%（59/75）在起病后甲型H1N1流感病毒核酸阳性持续≤7 d,平均年龄为（22.25±10.38）岁;21.3%（16/75）病毒持续＞7 d,年龄为（17.16±13.66）岁.对其中56例患者细胞与体液免疫功能进行分析,发现其IL-17表达明显低于季节性流感和健康人（P＜0.01）.进一步研究发现,10例病毒持续＞7 d的患者IL-17表达值（1.91±0.80）明显低于46例病毒持续≤7 d者IL-17表达（3.05±1.59）（P＜0.05）,也明显低于季节性流感（P＜0.01）和正常对照组（P＜0.001）.比较三治疗组抗病毒治疗5 d疗程结束时病毒核酸转阴率,分别为组Ⅲ92.86%,组Ⅰ71.43%,组Ⅱ46.15%,组Ⅱ明显低于前两组（分别为P＜0.01,P＜0.05）.组Ⅲ经治疗后体温恢复正常时间较组Ⅰ、组Ⅱ缩短（P＜0.05）.结论 IL-17和年龄与甲型H1N1流感病毒感染及排毒时间长短可能存在一定关系.奥司他韦联合中药治疗在抗病毒疗效和减轻症状方面均有其独特优势.     

中国首例甲型H1N1流感二代病例的临床特征

目的了解2009年我国首例甲型H1N1流感二代病例的流行病学、临床、病原学检查特点及预后转归。方法对患者流行病学及临床资料进行回顾性分析,并采用实时荧光聚合酶链反应测定甲型H1N1流感病毒核酸。结果患者与甲型H1N1流感输入病例接触1天后发病。以发热、咽痛、咳嗽起病,白细胞及CD4＋T淋巴细胞计数降低,无肺炎等并发症。多级机构检测咽拭子甲型H1N1流感病毒核酸阳性确诊甲型H1N1流感。RT-PCR测序证实其病毒核苷酸序列与一代输入病例的一致,同源性为100%。经奥司他韦抗病毒及对症治疗痊愈出院。结论本病例的传染源明确,为我国首例报告的甲型H1N1流感二代确诊病例,其临床表现轻,病情恢复快。未发生院内感染,早隔离早诊断等防控措施有效。     

基于甲型H1N1流感的流行病社会影响分析

2009年流行的H1N1的甲型禽流感是整合了人季节性H3N2流感、禽流感、欧亚猪流感、古典猪流感的四源重组毒株。流感病毒是一种高变异的病毒,流感属于呼吸道疾病,传播范围很广。本文主要讨论流感大发展史,流感的特点,流感的社会影响,还有病毒与人类进化的关系。     

应用巢式RT-PCR扩增HA和NA基因片段并测序鉴定甲型H1N1流感病毒

目的 建立一种利用巢式RT-PCR特异扩增HA和NA基因片段并测序鉴定甲型H1N1流感病毒的技术.方法 设计两套共7条特异引物,通过巢式RT-PCR分别扩增甲型H1N1流感病毒HA和NA基因片段并测序,所得序列与人感染甲型流感病毒主要HA和NA亚型序列进行进化树分析以对结果作进一步鉴定,蛋白序列比对后分析其特征.结果 4例甲型H1N1流感患者流感病毒HA和NA基因RT-PCR扩增均分别得到442 bp和543 bp片段产物.核苷酸序列进化分析表明,该4例患者HA和NA序列分别与2009年爆发的甲型H1N1流感病毒HA及NA序列聚集在一起,与季节性H1、H2、H3、人禽流感H5亚型及季节性N1、N2、人禽流感N1亚型特异分开.蛋白序列分析表明,4例患者流感病毒HA蛋白裂解位点附近氨基酸序列均为PSIQSR↓GLF,不具有高致病性流感病毒的特性,NA蛋白第275位氨基酸为His,未出现H275Y的耐药变异.结论 本方法能特异扩增甲型H1N1流感病毒HA和NA基因片段,测序后可用于甲型H1N1流感病毒的进一步鉴定;同时,得到的序列也可用于流感病毒致病力及耐药性的分析.     

2015-2016年度中国甲型H1N1亚型流感病毒疫苗候选株的制备及鉴定CSCD

目的 为获得2015-2016年度中国流行的甲型H1N1亚型流感病毒疫苗候选株,制备流感病毒重配株并对其进行鉴定.方法 采用经典重配的方法,将H1N1亚型流感病毒流行株与H3N2亚型的鸡胚高产重配母本株（X-157株）在鸡胚上进行混合培养.用H3亚型的HA蛋白抗血清和X-157株全病毒抗血清对混合培养病毒进行阴性筛选.阴性筛选后HA滴度较高的病毒用Real-Time PCR法对表面蛋白基因型进行鉴定.对表面蛋白基因型正确的毒株用限制性内切酶酶切鉴定法鉴定其内部基因组成.进一步对HA和NA基因进行Sanger法测序,并用表面基因无氨基酸位点突变的毒株免疫雪貂,进行双向血凝抑制（Two-way hemagglutination inhibition test,HI）试验.结果 Real-Time PCR筛选出5株表面蛋白基因型正确的毒株.经内部基因鉴定其中4株为6＋2组成,1株为5＋3组成.5株重配株的HA和NA基因均未发生氨基酸位点突变.5株重配株HA滴度均维持在1 024以上.最终选取的12号重配株免疫原性良好,HI滴度达5 120,双向HI试验均通过.重配后疫苗株在鸡胚上的产量是重配前野毒株的64倍.结论 成功制备了2015-2016年度中国流行的甲型H1N1亚型流感病毒疫苗株,为疫苗贮备和疾病防控奠定了基础.     

新型甲型H1N1流感的实验室检测特征及分析

目的比较新型甲型H1N1流感、季节性流感及普通上呼吸道感染的实验室检测特征,进一步认识新型甲型H1N1流感的特点并分析产生的可能机制。方法对我院2009年5～7月收治的新型甲型H1N1流感、季节性流感及普通上呼吸道感染病例的入院实验室检测资料进行回顾性分析。结果新型甲型H1N1流感患者入院时平均血钾为（3.43±0.33）mmol/L,低于季节性流感组和普通上呼吸道感染组,甲型H1N1流感中伴有低钾血症（血钾〈3.5mmol/L）者占60.22%,明显高于另外两组,但合并低钾血症者的血钾平均值在三组间并无明显差异;与另两组相比,新型甲型H1N1流感组外周血白细胞、中性粒细胞、CD4＋T细胞计数降低;其他实验室检测指标包括血钠、血钙、血磷、LDH活性、CK活性等在三组间并无统计学差异。结论新型甲型H1N1流感实验室检测特征包括血钾降低、白细胞、中性粒细胞、CD4＋T细胞减少,其中低钾血症是新型甲型H1N1流感的一个显著实验室特征,其发生的具体机制尚待进一步研究。     

从人分离出两株甲型流感H9N2亚型毒株内部基因特性的研究

目的 了解2株从人分离出的H9N2亚型毒株内部基因特性，并弄清其来源。方法 用RT-PCR扩增目的基因，用P^CEM-T Vector(美国Promega公司)，4℃过夜连接，重组质粒转入dH5a细菌，筛选阳性菌落，酶切鉴定，送六合通公司自动测序。然后进行进化树分析。结果 2株测定毒株内部基因均为G9基因系，它们相互间除PA基因有差异外，其余5个基因均相同。结论 2株测定毒株的基因组均为G9基因系，它们是由携带不同基因特性H9N2毒株的禽群分别直接感染人，而不是来自同一禽的H9N2亚型流感病毒。     

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...     

Pandemic influenza A(H1N1)pdm09: risk of infection in primary healthcare workers

Background

Healthcare workers in primary care are at risk of infection during an influenza pandemic. The 2009 influenza pandemic provided an opportunity to assess this risk.

Aim

To measure the prevalence of seropositivity to influenza A(H1N1)pdm09 among primary healthcare workers in Canterbury, New Zealand, following the 2009 influenza pandemic, and to examine associations between seropositivity and participants’ sociodemographic characteristics, professional roles, work patterns, and seasonal influenza vaccination status.

Design and setting

An observational study involving a questionnaire and testing for influenza A(H1N1)pdm09 seropositivity in all primary healthcare workers in Canterbury, New Zealand between December 2009 and February 2010.

Method

Participants completed a questionnaire that recorded sociodemographic and professional data, symptoms of influenza-like illness, history of seasonal influenza vaccination, and work patterns. Serum samples were collected and haemagglutination inhibition antibody titres to influenza A(H1N1)pdm09 measured.

Results

Questionnaires and serum samples were received from 1027 participants, from a workforce of 1476 (response rate 70%). Seropositivity was detected in 224 participants (22%). Receipt of seasonal influenza vaccine (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.2 to 3.3), recall of influenza (OR = 1.9, 95% CI = 1.3 to 2.8), and age ≤45 years (OR = 1.4, 95% CI = 1.0 to 1.9) were associated with seropositivity.

Conclusion

A total of 22% of primary care healthcare workers were seropositive. Younger participants, those who recalled having influenza, and those who had been vaccinated against seasonal influenza were more likely to be seropositive. Working in a dedicated influenza centre was not associated with an increased risk of seropositivity.     

Characteristics of outpatients with pandemic H1N1/09 influenza in a tertiary care university hospital in Korea

The pandemic H1N1/09 emerged rapidly in Korea. Here, we describe the clinical characteristics of outpatients in Seoul, Korea who were infected in the 2009 H1N1 pandemic. We reviewed the cases of outpatients with pandemic H1N1/09 who visited a tertiary care teaching hospital between September 1 and December 31, 2009. Infection with pandemic H1N1/09 was confirmed by molecular tests. Of a total of 7,182 tests, 3,020 (42.0%) were positive. Compared with 473 cases of influenza- like illness (ILI), the 586 confirmed cases of pandemic H1N1/09 differed in age [odds ratio (OR) 0.975] and fulfilling at least one of the following factors: age < 5 or ≥ 65 years, history of contact with other pandemic H1N1/09-infected individuals (OR 0.611), fever ≥ 37.8°C (OR 3.567), cough (OR 2.290), and myalgia (OR 1.559). The sensitivity of the best criteria, "fever (≥ 37.8°C) plus cough" (41.03%) in this study was lower than that of the Korea Centers for Disease Control and Prevention (KCDC) criteria (47.95%), whereas the positive likelihood ratio (3.55) and positive predictive value (81.6) of this criteria was higher than those of the KCDC criteria (2.98 and 78.7, respectively). The clinical characteristics of pandemic H1N1/09 are, in many regards, indistinguishable from those of ILI. Moreover, the accuracy and predictability of criteria which include only symptoms or signs were not sufficient to diagnose pandemic H1N1/09 infection. Therefore, use of a combination of symptoms with confirmatory laboratory testing is necessary for accurate diagnosis of pandemic H1N1/09.     

Fatal cases of 2009 pandemic influenza A (H1N1) in Korea

The aim of this study was to describe the features of deaths associated with the 2009 pandemic influenza A (H1N1) by 26 November 2009 in Korea. We collected standardized case reports on 115 confirmed deaths through a nationwide enhanced influenza surveillance system. The median age was 61 yr (interquartile range [IQR], 0.2-97 yr) and 58 (50.4%) were females. The case fatality rate was estimated as 16 per 100,000 cases. The age-related mortality rate had a J-shaped curve. Eighty-three patients (72.2%) had at least 1 underlying medical disease. Bacterial co-infections were detected in the blood or sputum specimens from 34 patients. Of the 63 patients who were hospitalized in the intensive care unit (ICU), the median time from symptom onset to hospital admission was 2 days (IQR, 0-22 days), and the median time from hospitalization to ICU admission was 1 day (IQR, 0-17 days). Neuraminidase inhibitors were administered to 100 patients (87.0%), 36% of whom began treatment within 2 days. In conclusion, fatal cases from the 2009 influenza A (H1N1) infection in Korea are mainly aged individuals with underlying disease, and associated with pneumonia, bacterial co-infections, and multi-organ failure.     

深圳地区甲1(H1N1)亚型流感病毒基因特性的研究

目的　了解近几年H1N1亚型毒株在深圳地区人群中活动加强及“O”相特性出现的分子生物学基础及其基因演变的特性。方法　病毒粒RNA经逆转录合成cDNA,用PCR扩增,产物纯化,采用双脱氧链末端终止法进行核苷酸序列测定并推导出其所编码的氨基酸序列。进化树分析用DNASTAR公司出品的序列分析软件,MegAlign(103版)的Editseq(369版)。结果　根据病毒粒HA1基因特性,至少1995年以来深圳地区人群中同时流行着基因特性不同的三系毒株;1995～1997年H1N1毒株与A新加坡686(H1N1)病毒相比较,其HA1蛋白分子上第54和155位上分别插入和缺失一个糖基化点,同时氨基酸序列发生了替换。结论　近年来深圳地区人群中同时流行着HA1基因不同的三系H1N1亚型毒株。由于HA1蛋白分子上氨基酸序列发生了替换,尤其糖基化位点插入和缺失,造成1995年以来H1N1毒株活动加强,这些可能与毒株“O”相特性再现密切相关。