Mencacci Antonella, Gili Alessio, Gidari Anna, Schiaroli Elisabetta, Russo Carla, Cenci Elio, Camilloni Barbara, Graziani Alessandro, Melelli-Roia Arduino, Francisci Daniela, Stracci Fabrizio
Department of Medicine and Surgery, Microbiology and Clinical Microbiology, Santa Maria Della Misericordia" Hospital, University of Perugia, 06129 Perugia, Italy.
Public Health Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy.
J Clin Med. 2021 Sep 7;10(18):4037. doi: 10.3390/jcm10184037.
In SARS-CoV-2 infection, viral RNA may persist in respiratory samples for several weeks after the resolution of symptoms. Criteria to assess the end of infectivity are not unequivocally defined. In some countries, time from diagnosis is the unique criterion used, in addition to symptom cessation. This study evaluates the role of the Lumipulse Antigen Assay (LAA) for the safe end of isolation of patients ≥21 days after the diagnosis of infection.
A total of 671 nasopharyngeal swabs from patients diagnosed with infection at least 21 days before were assessed by RT-PCR and LAA, and the role of LAA in predicting the absence of infectivity was evaluated by virus cell culture.
Viable virus was present in 10/138 cultured samples. Eight out of ten infective patients suffered from a concomitant disease, predisposing them to long-term shedding of infective virus. In particular, infectious virus was isolated from 10/20 RT-PCR+/LAA+ cultured samples, whereas no viable virus was found in all 118 RT-PCR+/LAA- cultured swabs. LLA and RT-PCR agreed in 484/671 (72.1%) samples, with 100% and 26.7% concordance in RT-PCR negative and positive samples, respectively.
Viable virus can be found ≥21 days after diagnosis in immunocompromised or severely ill patients. LAA better than RT-PCR predicts non-infectivity of patients and can be safely used to end isolation in cases with long persistence of viral RNA in the respiratory tract.
在新型冠状病毒感染中，症状缓解后，呼吸道样本中的病毒RNA可能会持续存在数周。评估传染性结束的标准尚未明确界定。在一些国家，除症状消失外，自诊断起的时间是唯一使用的标准。本研究评估了Lumipulse抗原检测（LAA）在感染诊断后≥21天患者安全解除隔离中的作用。
对至少在21天前被诊断感染的患者的671份鼻咽拭子进行逆转录聚合酶链反应（RT-PCR）和LAA检测，并通过病毒细胞培养评估LAA在预测无传染性方面的作用。
138份培养样本中有10份存在活病毒。10名感染患者中有8名患有合并症，这使他们易于长期排出感染性病毒。特别是，从10/20份RT-PCR阳性/LAA阳性的培养样本中分离出感染性病毒，而在所有118份RT-PCR阳性/LAA阴性的培养拭子中均未发现活病毒。LAA和RT-PCR在484/671（72.1%）的样本中结果一致，在RT-PCR阴性和阳性样本中的一致性分别为100%和26.7%。
在免疫功能低下或重症患者中，诊断后≥21天仍可检测到活病毒。LAA比RT-PCR更能预测患者的无传染性，可安全用于呼吸道病毒RNA长期持续存在情况下的解除隔离。
