The etiological role of common respiratory viruses in acute respiratory infections in older adults: A systematic review and meta-analysis

Acute respiratory tract infections (ARI) constitute a substantial disease burden in adults and elderly individuals. We aimed to identify all case-control studies investigating the potential role of respiratory viruses in the etiology of ARI in older adults aged ≥65 years. We conducted a systematic literature review (across 7 databases) of case-control studies published from 1996 to 2017 that investigated the viral profile of older adults with and those without ARI. We then computed a pooled odds ratio (OR) with a 95% confidence interval and virus-specific attributable fraction among the exposed (AFE) for 8 common viruses: respiratory syncytial virus (RSV), influenza virus (Flu), parainfluenza virus (PIV), human metapneumovirus (HMPV), adenovirus (AdV), rhinovirus (RV), bocavirus (BoV), and coronavirus (CoV). From the 16 studies included, there was strong evidence of possible causal attribution for RSV (OR, 8.5 [95% CI, 3.9-18.5]; AFE, 88%), Flu (OR, 8.3 [95% CI, 4.4-15.9]; AFE, 88%), PIV (OR, not available; AFE, approximately 100%), HMPV (OR, 9.8 [95% CI, 2.3-41.0]; AFE, 90%), AdV (OR, not available; AFE, approximately 100%), RV (OR, 7.1 [95% CI, 3.7-13.6]; AFE, 86%) and CoV (OR, 2.8 [95% CI, 2.0-4.1]; AFE, 65%) in older adults presenting with ARI, compared with those without respiratory symptoms (ie, asymptomatic individuals) or healthy older adults. However, there was no significant difference in the detection of BoV in cases and controls. This review supports RSV, Flu, PIV, HMPV, AdV, RV, and CoV as important causes of ARI in older adults and provides quantitative estimates of the absolute proportion of virus-associated ARI cases to which a viral cause can be attributed. Disease burden estimates should take into account the appropriate AFE estimates (for older adults) that we report.

急性呼吸道感染（Acute respiratory tract infections, ARI）在成人与老年人群中造成了沉重的疾病负担。本研究旨在检索所有探讨呼吸道病毒在≥65岁老年人群急性呼吸道感染病因学中潜在作用的病例对照研究。我们针对1996年至2017年间发表的、探讨伴与不伴急性呼吸道感染的老年人群病毒谱的病例对照研究开展了系统文献综述（覆盖7个数据库）。随后，我们针对8种常见病毒计算了合并比值比（pooled odds ratio, OR）及95%置信区间（95% confidence interval），并计算了暴露人群的病毒特异性归因分数（virus-specific attributable fraction among the exposed, AFE），这8种病毒分别为：呼吸道合胞病毒（respiratory syncytial virus, RSV）、流感病毒（influenza virus, Flu）、副流感病毒（parainfluenza virus, PIV）、人偏肺病毒（human metapneumovirus, HMPV）、腺病毒（adenovirus, AdV）、鼻病毒（rhinovirus, RV）、博卡病毒（bocavirus, BoV）以及冠状病毒（coronavirus, CoV）。
纳入本次综述的16项研究显示，与无呼吸道症状人群（即无症状个体）或健康老年人群相比，罹患急性呼吸道感染的老年人群中，呼吸道合胞病毒（OR=8.5，95%CI=3.9~18.5；AFE=88%）、流感病毒（OR=8.3，95%CI=4.4~15.9；AFE=88%）、副流感病毒（OR数据未公开，AFE约为100%）、人偏肺病毒（OR=9.8，95%CI=2.3~41.0；AFE=90%）、腺病毒（OR数据未公开，AFE约为100%）、鼻病毒（OR=7.1，95%CI=3.7~13.6；AFE=86%）及冠状病毒（OR=2.8，95%CI=2.0~4.1；AFE=65%）存在明确的因果关联证据。不过，病例组与对照组的博卡病毒检出率无显著差异。
本综述证实，呼吸道合胞病毒、流感病毒、副流感病毒、人偏肺病毒、腺病毒、鼻病毒及冠状病毒是老年人群急性呼吸道感染的重要致病原，并提供了病毒相关急性呼吸道感染病例中可归因于病毒感染的绝对比例的量化估计值。疾病负担评估应纳入本研究报告的适配老年人群的AFE估计值。