Abeykoon A M Hasanthi, Wilson Madeleine, Subbarao Kanta, Geard Nicholas, Zachreson Cameron, Sullivan Sheena Geraldine
Department of Infectious Diseases, Melbourne Medical School, https://ror.org/01ej9dk98University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
WHO Collaborating Centre for Reference and Research on Influenza, Royal Melbourne Hospital, https://ror.org/01ej9dk98Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
Epidemiol Infect. 2025 Jun 20;153:e75. doi: 10.1017/S0950268825100174.
This systematic review synthesized evidence on the viral load of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) shedding in exhaled material to understand how the exhaled SARS-CoV-2 viral load of infected individuals varies with days since exposure. Medline, Scopus, and Web of Science databases were searched using a combination of search terms to identify articles that tested exhaled material from SARS-CoV-2 infected patients. Records were systematically screened and assessed for eligibility, following which reference lists of eligible articles were hand-searched to identify further relevant studies. Data extraction and quality assessment of individual studies were conducted prior to synthesizing the evidence. Forty-five articles that sampled exhaled breath, exhaled breath condensate, face masks, and cough samples were reviewed. The variation in the SARS-CoV-2 viral load in these materials was considerable with the detection of viral RNA shed during breathing as far as 43 days after symptom onset. The replication-competent virus was present in all four sample types, with the majority isolated during the first week of symptoms onset. Variations in the sample types and testing protocols precluded meta-analysis. High heterogeneity in exhaled SARS-CoV-2 viral load is likely due to host and viral factors as well as variations in sampling and diagnostic methodologies. Evidence on SARS-CoV-2 shedding in exhaled material is scarce and more controlled fundamental studies are needed to assess this important route of viral shedding.
本系统评价综合了关于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）呼出物中病毒载量的证据，以了解受感染个体呼出的SARS-CoV-2病毒载量如何随暴露后天数变化。使用搜索词组合在Medline、Scopus和Web of Science数据库中进行检索，以识别检测SARS-CoV-2感染患者呼出物的文章。对记录进行系统筛选和资格评估，随后人工检索符合条件文章的参考文献列表以识别更多相关研究。在综合证据之前，对个体研究进行数据提取和质量评估。对45篇采集呼气、呼气冷凝物、口罩和咳嗽样本的文章进行了综述。这些材料中SARS-CoV-2病毒载量的变化很大，在症状出现后长达43天的呼吸过程中均可检测到病毒RNA脱落。在所有四种样本类型中均存在具有复制能力的病毒，大多数在症状出现的第一周分离出来。样本类型和检测方案的差异使得无法进行荟萃分析。呼出的SARS-CoV-2病毒载量高度异质性可能归因于宿主和病毒因素以及采样和诊断方法的差异。关于SARS-CoV-2在呼出物中脱落的证据很少，需要更多对照性基础研究来评估这一重要的病毒脱落途径。
