Department of Clinical Trials, Center for Advanced Medical Innovation, Kyushu University, Fukuoka, Japan.
Influenza Other Respir Viruses. 2012 May;6(3):211-7. doi: 10.1111/j.1750-2659.2011.00296.x. Epub 2011 Oct 10.
Influenza can be a serious illness, especially for older people, and reducing the impact of influenza in elderly is important. The objective of this study was to estimate the prevalence and postinfection outcomes of influenza among the over-50 population in Japan.
An observational study was designed to ascertain the proportion of influenza cases in a population aged ≥ 50 years with acute respiratory infection (ARI) and to determine the postinfection outcomes of their illness during the 2008-09 influenza season in Japan. Respiratory specimens obtained from a total of 401 patients were tested by PCR for influenza viruses, respiratory syncytial virus (RSV) and human metapneumovirus (hMPV). The effectiveness of the seasonal trivalent influenza vaccine was estimated by a test-negative case control analysis.
Seventeen outpatient clinics located in four separate areas of Japan.
Respiratory swab specimens from the ARI patients aged ≥ 50 years.
Laboratory confirmed influenza in patients presenting with ARI.
In all, 89 (22.2%) of the patients were positive for one of the tested viruses; 70 (78.7%) with influenza, 17 (19.1%) with RSV, and 2 (2.2%) with hMPV. Cough (95.7% vs 73.4%), loss of appetite (67.1% vs 35.5%), absence from work (50.0% vs 23.0%), impact on daily activity (90.0% vs 62.5%), and caregiver absence from work (5.7% vs 0.6%) were observed higher in influenza patients. The duration of feeling weakness (6.3 ± 5.4 vs 3.6 ± 1.9 days) and average days of reduced activity (5.2 vs 3.6 days) were longer for influenza patients. Vaccine effectiveness was estimated to be 32.1% (95% CI: -14.9, 59.9%).
Influenza was the dominant ARI-causing virus and the clinical and socio-economic outcomes imposed on patients over 50 years of age was high for influenza.
流感可能是一种严重的疾病，尤其是对于老年人而言，减轻老年人流感的影响非常重要。本研究的目的是评估日本 50 岁以上人群中流感的流行率和感染后结局。
本研究设计为观察性研究，旨在确定急性呼吸道感染（ARI）中≥50 岁人群中流感病例的比例，并确定 2008-09 流感季节日本 50 岁以上人群感染流感后的结局。从 401 例患者中采集呼吸道标本，通过 PCR 检测流感病毒、呼吸道合胞病毒（RSV）和人偏肺病毒（hMPV）。采用病例对照试验阴性设计估计季节性三价流感疫苗的效果。
日本四个不同地区的 17 家门诊。
≥50 岁ARI 患者的呼吸道拭子标本。
ARI 患者经实验室确诊的流感。
共有 89 例（22.2%）患者的一种被检测病毒呈阳性；70 例（78.7%）为流感病毒，17 例（19.1%）为 RSV，2 例（2.2%）为 hMPV。流感患者更易出现咳嗽（95.7%比 73.4%）、食欲不振（67.1%比 35.5%）、缺勤（50.0%比 23.0%）、影响日常活动（90.0%比 62.5%）和照顾者缺勤（5.7%比 0.6%）。流感患者感觉乏力的时间（6.3±5.4 天比 3.6±1.9 天）和活动减少的平均天数（5.2 天比 3.6 天）更长。疫苗的有效性估计为 32.1%（95%CI：-14.9，59.9%）。
流感是导致 ARI 的主要病毒，50 岁以上患者的临床和社会经济结局因流感而加重。
