Co-infection has been reported in patients with severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, but there is limited knowledge on co-infection among patients with coronavirus disease 2019 (COVID-19). The prevalence of co-infection was variable among COVID-19 patients in different studies, however, it could be up to 50% among non-survivors. Co-pathogens included bacteria, such as Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumonia, Legionella pneumophila and Acinetobacter baumannii; Candida species and Aspergillus flavus; and viruses such as influenza, coronavirus, rhinovirus/enterovirus, parainfluenza, metapneumovirus, influenza B virus, and human immunodeficiency virus. Influenza A was one of the most common co-infective viruses, which may have caused initial false-negative results of real-time reverse-transcriptase polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Laboratory and imaging findings alone cannot help distinguish co-infection from SARS-CoV-2 infection. Newly developed syndromic multiplex panels that incorporate SARS-CoV-2 may facilitate the early detection of co-infection among COVID-19 patients. By contrast, clinicians cannot rule out SARS-CoV-2 infection by ruling in other respiratory pathogens through old syndromic multiplex panels at this stage of the COVID-19 pandemic. Therefore, clinicians must have a high index of suspicion for coinfection among COVID-19 patients. Clinicians can neither rule out other co-infections caused by respiratory pathogens by diagnosing SARS-CoV-2 infection nor rule out COVID-19 by detection of non-SARS-CoV-2 respiratory pathogens. After recognizing the possible pathogens causing co-infection among COVID-19 patients, appropriate antimicrobial agents can be recommended.

据报道，严重急性呼吸系统综合症 (SARS) 和中东呼吸系统综合症患者合并感染，但对 2019 年冠状病毒病 (COVID-19) 患者合并感染的了解有限。在不同的研究中，COVID-19 患者合并感染的发生率各不相同，但在非幸存者中可能高达 50%。共病原体包括细菌，如肺炎链球菌、金黄色葡萄球菌、肺炎克雷伯菌、肺炎支原体、肺炎衣原体、嗜肺军团菌和鲍曼不动杆菌；念珠菌属和黄曲霉; 流感病毒、冠状病毒、鼻病毒/肠道病毒、副流感病毒、偏肺病毒、乙型流感病毒和人类免疫缺陷病毒等病毒。甲型流感是最常见的合并感染病毒之一，可能导致严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 实时逆转录酶聚合酶链反应的初始假阴性结果。单靠实验室和影像学检查结果无法帮助区分合并感染和 SARS-CoV-2 感染。新开发的包含 SARS-CoV-2 的综合症候群组合可能有助于早期发现 COVID-19 患者合并感染。相比之下，在 COVID-19 大流行的现阶段，临床医生不能通过旧的综合症多重检测组排除其他呼吸道病原体来排除 SARS-CoV-2 感染。所以，临床医生必须高度怀疑 COVID-19 患者合并感染。临床医生既不能通过诊断 SARS-CoV-2 感染来排除由呼吸道病原体引起的其他合并感染，也不能通过检测非 SARS-CoV-2 呼吸道病原体来排除 COVID-19。在识别出可能导致 COVID-19 患者合并感染的病原体后，可以推荐使用合适的抗菌药物。