Supplementary Material for: Incidence of Respiratory Viral Infections Detected by PCR and Real-Time PCR in Adult Patients with Community-Acquired Pneumonia: A Meta-Analysis

Background: With the development of more rapid and sensitive detection methods based on PCR techniques, the contributions of respiratory viral infections to community-acquired pneumonia (CAP) in adult patients are being more and more recognized. Yet, up to now, there has been a lack of synthetic data that clearly demonstrates the incidence of respiratory viral infections in adult patients with CAP. Objectives: We intended to demonstrate the incidence of respiratory viral infections detected by PCR and real-time PCR in adult patients with CAP. Methods: We searched PubMed and Embase for studies providing the incidence of respiratory viral infections in adult patients with CAP. We investigated potential sources of heterogeneity by a univariant metaregression analysis and calculated the combined incidence of viral infections, viral infections mixed with other pathogens and individual respiratory virus species. Results: We eventually identified 23 eligible reports with a total number of 6,404 patients. Incidences ranged from 8.6 to 56.2% for overall respiratory viral infections. We noted significant heterogeneity in incidence estimates for the incidence of viral infections (Cochran's χ2 = 269.9, p < 0.0001, I2 = 91.8%). The combined incidence of viral infections was 22.4% (95% CI = 19.0-25.7). Incidences of viral coinfections with other pathogens ranged from 3 to 28%. A high level of heterogeneity was identified as well during the estimates for incidences of coinfections (χ2 = 200.9, p < 0.0001, I2 = 91.5%). The combined incidence of viral coinfections with other pathogens was 12.4% (95% CI = 9.7-15.0). Our heterogeneity analyses suggested that a lower respiratory tract sample was associated with higher overall viral incidence. Moreover, the influenza virus, rhinovirus and coronavirus were the 3 most frequently detected viral pathogens in adult patients with CAP according to our study. Conclusions: Respiratory viruses are probably crucial pathogens of adult patients with CAP, with the influenza virus being the most frequent viral pathogen identified. More than half of the viral infections are characterized as mixed infections with other pathogens.

背景：随着基于聚合酶链式反应（Polymerase Chain Reaction, PCR）技术的更快速、高灵敏检测方法的发展，呼吸道病毒感染在成人社区获得性肺炎（Community-Acquired Pneumonia, CAP）患者中的致病贡献正得到越来越多的认可。然而，截至目前，仍缺乏能够明确阐明成人社区获得性肺炎患者呼吸道病毒感染发病率的合成数据。
目的：本研究旨在阐明经PCR及实时聚合酶链式反应（real-time PCR）检测的成人社区获得性肺炎患者呼吸道病毒感染的发病率。
方法：我们在PubMed与Embase数据库中检索了报道成人社区获得性肺炎患者呼吸道病毒感染发病率的相关研究。通过单变量元回归分析探究潜在异质性来源，并计算了病毒感染、合并其他病原体的病毒感染以及单一呼吸道病毒种类的合并发病率。
结果：最终纳入23篇符合纳入标准的文献，共计6404例患者。整体呼吸道病毒感染的发病率范围为8.6%至56.2%。我们观察到病毒感染发病率的估计值存在显著异质性（科克伦χ²=269.9，P<0.0001，I²=91.8%）。病毒感染的合并发病率为22.4%（95%置信区间：19.0~25.7）。合并其他病原体的病毒感染发病率范围为3%至28%。合并感染的发病率估计值同样存在较高异质性（χ²=200.9，P<0.0001，I²=91.5%）。合并其他病原体的病毒感染的合并发病率为12.4%（95%置信区间：9.7~15.0）。异质性分析结果显示，下呼吸道样本与更高的整体病毒发病率相关。此外，本研究发现，流感病毒、鼻病毒与冠状病毒是成人社区获得性肺炎患者中最常被检出的三种病毒病原体。
结论：呼吸道病毒可能是成人社区获得性肺炎患者的关键致病病原体，其中流感病毒是最常被检出的病毒病原体。超过半数的病毒感染表现为与其他病原体的混合感染。