Department of Medical Microbiology and Immunology, Faculty of Medicine, Zagazig University, Zagazig, Egypt; Viral Infection Working Group of International Society of Antimicrobial Chemotherapy VIWG/ISAC, UK.
Viral Infection Working Group of International Society of Antimicrobial Chemotherapy VIWG/ISAC, UK; Department of Tropical Medicine and Infectious Diseases, Zagazig University, Zagazig, Egypt.
Travel Med Infect Dis. 2022 Jul-Aug;48:102334. doi: 10.1016/j.tmaid.2022.102334. Epub 2022 Apr 22.
It has been found that patients recovered from COVID 19 may still test Reverse Transcriptase- Polymerase Chain Reaction (RT- PCR) positive without being infectious; the reasons are unclear. The occurrence of false-negative results of RT- PCR interferes with a proper diagnosis. The objectives of that work were to determine factors associated with persistently detectable SARS-CoV-2 RNA among recovered hospitalized patients and to determine the incidence of false-negative RT-PCR results and associated factors.
Relevant data were collected from 482 COVID 19 patients hospitalized in six referral centers from four countries.
The median duration of RT- PCR conversion to negative was 20 days. Out of 482 studied patients, 8.7% tested positive after more than four weeks and were considered prolonged convertors. Binary logistic regression analysis revealed headache as an independent risk factor for short conversion time while fever, hypertension, chronic obstructive pulmonary disease, lymphopenia, elevated erythrocyte sedimentation rate, and the number of lobes affected, and bilateralism were found to be independent risk factors for prolonged positivity. Eighteen patients had initial negative results then turned positive after 24-48 h. Associated factors and outcomes were identified.
Identifying patients with a high likelihood of COVID-19 despite a negative RT-PCR is critical for effective clinical care. However, patient isolation resumption depending on positive RT-PCR despite clinical and radiological recovery is an overrating that greatly burdens the health sector.
已发现，一些 COVID-19 患者在康复后，其逆转录-聚合酶链反应（RT-PCR）检测结果仍呈阳性，但并无传染性，其原因尚不清楚。RT-PCR 检测结果出现假阴性会干扰正确诊断。本研究旨在确定与住院康复患者 SARS-CoV-2 RNA 持续可检测相关的因素，并确定假阴性 RT-PCR 结果的发生率及其相关因素。
从来自四个国家六个转诊中心的 482 例 COVID-19 住院患者中收集相关数据。
RT-PCR 转为阴性的中位时间为 20 天。在 482 例研究患者中，8.7%的患者在 4 周以上时检测结果仍为阳性，被认为是持续阳性转化者。二元逻辑回归分析显示，头痛是 RT-PCR 快速转阴的独立危险因素，而发热、高血压、慢性阻塞性肺疾病、淋巴细胞减少、红细胞沉降率升高、受累肺叶数量和双侧病变是持续阳性的独立危险因素。18 例患者最初 RT-PCR 检测结果为阴性，24-48 小时后转为阳性。并确定了其相关因素和结果。
对于有效临床护理而言，识别出 RT-PCR 检测结果阴性但仍高度疑似 COVID-19 的患者至关重要。然而，尽管临床和影像学已恢复，但根据 RT-PCR 阳性结果而恢复对患者的隔离，这是一种过度评估，会给卫生系统带来沉重负担。
