Section of Clinical Biochemistry, Department of Neuroscience, Biomedicine and Movement, University of Verona, Piazzale LA Scuro, 37134 Verona, Italy.
Department of Medical Laboratory Diagnostics, University Hospital Sveti Duh, Zagreb, Croatia.
Clin Chem Lab Med. 2020 Jun 25;58(7):1070-1076. doi: 10.1515/cclm-2020-0285.
A novel zoonotic coronavirus outbreak is spreading all over the world. This pandemic disease has now been defined as novel coronavirus disease 2019 (COVID-19), and is sustained by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the current gold standard for the etiological diagnosis of SARS-CoV-2 infection is (real time) reverse transcription polymerase chain reaction (rRT-PCR) on respiratory tract specimens, the diagnostic accuracy of this technique shall be considered a foremost prerequisite. Overall, potential RT-PCR vulnerabilities include general preanalytical issues such as identification problems, inadequate procedures for collection, handling, transport and storage of the swabs, collection of inappropriate or inadequate material (for quality or volume), presence of interfering substances, manual errors, as well as specific aspects such as sample contamination and testing patients receiving antiretroviral therapy. Some analytical problems may also contribute to jeopardize the diagnostic accuracy, including testing outside the diagnostic window, active viral recombination, use of inadequately validated assays, insufficient harmonization, instrument malfunctioning, along with other specific technical issues. Some practical indications can hence be identified for minimizing the risk of diagnostic errors, encompassing the improvement of diagnostic accuracy by combining clinical evidence with results of chest computed tomography (CT) and RT-PCR, interpretation of RT-PCR results according to epidemiologic, clinical and radiological factors, recollection and testing of upper (or lower) respiratory specimens in patients with negative RT-PCR test results and high suspicion or probability of infection, dissemination of clear instructions for specimen (especially swab) collection, management and storage, together with refinement of molecular target(s) and thorough compliance with analytical procedures, including quality assurance.
一种新型人畜共患冠状病毒正在全球范围内传播。这种大流行性疾病现在被定义为 2019 年新型冠状病毒病（COVID-19），由严重急性呼吸系统综合征冠状病毒 2（SARS-CoV-2）引起。由于目前 SARS-CoV-2 感染的病因诊断金标准是呼吸道标本的（实时）逆转录聚合酶链反应（rRT-PCR），因此应考虑该技术的诊断准确性作为首要前提。总的来说，潜在的 RT-PCR 弱点包括一般的分析前问题，例如鉴定问题、采集、处理、运输和储存拭子的程序不当、采集不当或不足的材料（质量或体积）、存在干扰物质、人为错误，以及样本污染和检测接受抗逆转录病毒治疗的患者等具体方面。一些分析问题也可能影响诊断准确性，包括在诊断窗口期之外进行检测、病毒的活性重组、使用验证不足的检测方法、缺乏充分的协调、仪器故障以及其他特定技术问题。因此，可以确定一些实用的指示，以最大程度地降低诊断错误的风险，包括通过将临床证据与胸部计算机断层扫描（CT）和 RT-PCR 结果相结合来提高诊断准确性，根据流行病学、临床和影像学因素解释 RT-PCR 结果，对 RT-PCR 检测结果为阴性但高度怀疑或感染可能性高的患者重新采集和检测上（或下）呼吸道标本，明确标本（尤其是拭子）采集、管理和储存的说明，以及分子靶标的细化和对分析程序的全面遵守，包括质量保证。
