Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, China.
The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
J Dent Res. 2020 Oct;99(11):1239-1244. doi: 10.1177/0022034520946251. Epub 2020 Aug 3.
Coronavirus disease 2019 (COVID-19) has caused a global pandemic associated with substantial morbidity and mortality. Nasopharyngeal swabs and sputum samples are generally collected for serial viral load screening of respiratory contagions, but temporal profiles of these samples are not completely clear in patients with COVID-19. We performed an observational cohort study at Renmin Hospital of Wuhan University, which involved 31 patients with confirmed COVID-19 with or without underlying diseases. We obtained samples from each patient, and serial viral load was measured by real-time quantitative polymerase chain reaction. We found that the viral load in the sputum was inclined to be higher than samples obtained from the nasopharyngeal swab at disease presentation. Moreover, the viral load in the sputum decreased more slowly over time than in the nasopharyngeal group as the disease progressed. Interestingly, even when samples in the nasopharyngeal swab turned negative, it was commonly observed that patients with underlying diseases, especially hypertension and diabetes, remained positive for COVID-19 and required a longer period for the sputum samples to turn negative. These combined findings emphasize the importance of tracking sputum samples even in patients with negative tests from nasopharyngeal swabs, especially for those with underlying conditions. In conclusion, this work reinforces the importance of sputum samples for SARS-CoV-2 detection to minimize transmission of COVID-19 within the community.
新型冠状病毒病（COVID-19）已在全球范围内引发大流行，导致大量发病和死亡。通常采集鼻咽拭子和痰液样本进行呼吸道传染病的连续病毒载量筛查，但 COVID-19 患者这些样本的时间分布并不完全清楚。我们在武汉大学人民医院进行了一项观察性队列研究，共涉及 31 例确诊 COVID-19 患者，包括合并或不合并基础疾病的患者。我们从每位患者采集样本，通过实时定量聚合酶链反应（PCR）测量连续病毒载量。我们发现，在疾病发作时，痰液中的病毒载量往往高于鼻咽拭子样本。此外，随着疾病的进展，痰液中的病毒载量下降速度比鼻咽组慢。有趣的是，即使鼻咽拭子样本转为阴性，我们也常观察到合并基础疾病（尤其是高血压和糖尿病）的患者仍为 COVID-19 阳性，需要更长时间痰液样本才能转为阴性。这些综合发现强调了即使在鼻咽拭子检测为阴性的患者中，也应追踪痰液样本的重要性，特别是对有基础疾病的患者。总之，这项工作强化了通过检测痰液样本来发现 SARS-CoV-2 的重要性，以最大程度减少 COVID-19 在社区内的传播。
