Syndromic testing for respiratory pathogens but not National Early Warning Score can be used to identify viral cause in hospitalised adults with lower respiratory tract infections

Community-acquired lower respiratory tract infection (LRTI) is a common reason for hospitalisation. Antibiotics are frequently used while diagnostic microbiological methods are underutilised in the acute setting. We aimed to investigate the relative proportion of viral and bacterial infections in this patient group and explore methods for proper targeting of antimicrobial therapy. We collected nasopharyngeal samples prospectively from adults hospitalised with LRTIs during three consecutive winter seasons (2016–2019). Syndromic nasopharyngeal testing was performed using a multiplex PCR panel including 16 viruses and four bacteria. Medical records were reviewed for clinical data. Out of 220 included patients, a viral pathogen was detected in 74 (34%), a bacterial pathogen in 63 (39%), both viral and bacterial pathogens in 49 (22%), while the aetiology remained unknown in 34 (15%) cases. The proportion of infections with an identified pathogen increased from 38% to 85% when syndromic testing was added to standard-of-care testing. Viral infections were associated with a low CRP level and absence of pulmonary infiltrates. A high National Early Warning Score did not predict bacterial infections. Syndromic testing by a multiplex PCR panel identified a viral infection or viral/bacterial coinfection in a majority of hospitalised adult patients with community-acquired LRTIs.

社区获得性下呼吸道感染（Community-acquired lower respiratory tract infection, LRTI）是住院治疗的常见病因。临床急性诊疗场景中，抗生素的使用较为普遍，但病原微生物诊断方法的应用却未得到充分利用。本研究旨在明确该患者群体中病毒与细菌感染的相对占比，并探索实现抗菌治疗精准靶向的可行策略。

本研究前瞻性采集了2016至2019年连续三个冬季期间，因社区获得性下呼吸道感染住院的成年患者的鼻咽样本。采用涵盖16种病毒及4种细菌的多重PCR（multiplex PCR）检测面板，对鼻咽样本开展综合征病原检测；同时回顾患者电子病历以提取临床数据。

纳入研究的220例患者中，74例（34%）检出病毒病原体，63例（39%）检出细菌病原体，49例（22%）同时检出病毒与细菌病原体，另有34例（15%）未明确致病原。若将综合征病原检测纳入标准诊疗流程，可明确致病原的感染占比将从38%提升至85%。

病毒感染与C反应蛋白（C-reactive protein, CRP）水平较低及肺部无浸润影存在相关性；较高的国家早期预警评分（National Early Warning Score, NEWS）无法预测细菌感染的发生。

采用多重PCR检测面板开展的综合征病原检测，可在多数社区获得性下呼吸道感染住院成年患者中检出病毒感染或病毒-细菌混合感染。