Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, People's Republic of China.
State Key Laboratory for Emerging Infectious Diseases, Department of Microbiology, Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People's Republic of China.
Emerg Microbes Infect. 2020 Dec;9(1):1356-1359. doi: 10.1080/22221751.2020.1775133.
During the Coronavirus disease 2019 (COVID-19) pandemic, logistic problems associated with specimen collection limited the SARS-CoV-2 testing, especially in the community. In this study, we assessed the use of posterior oropharyngeal saliva as specimens for the detection of SARS-CoV-2 in an automated point-of-care molecular assay. Archived nasopharyngeal swab (NPS) and posterior oropharyngeal saliva specimens of 58 COVID-19 patients were tested with the Xpert Xpress SARS-CoV-2 assay. SARS-CoV-2 was detected in either NPS or saliva specimens of all patients. Among them, 84.5% (49/58) tested positive in both NPS and saliva, 10.3% (6/58) tested positive in NPS only, and 5.2% (3/58) tested positive in saliva only. No significant difference in the detection rate was observed between NPS and saliva (McNemar's test = 0.5078). The detection rate was slightly higher for N2 (NPS 94.8% and Saliva 93.1%) than that of the E gene target (Saliva: 89.7% vs 82.8%) on both specimen types. Significantly earlier median Ct value was observed for NPS comparing to that of saliva on both E (26.8 vs 29.7, = 0.0002) and N2 gene target (29.3 vs 32.3, = 0.0002). The median Ct value of E gene target was significantly earlier than that of the N2 gene target for both NPS (26.8 vs 29.3, < 0.0001) and saliva (29.7 vs 32.3, < 0.0001). In conclusion, posterior oropharyngeal saliva and NPS were found to have similar detection rates in the point-of-care test for SARS-CoV-2 detection. Since posterior oropharyngeal saliva can be collected easily, the use of saliva as an alternative specimen type for SARS-CoV-2 detection is recommended.
在 2019 年冠状病毒病（COVID-19）大流行期间，与标本采集相关的后勤问题限制了 SARS-CoV-2 的检测，尤其是在社区中。在这项研究中，我们评估了在后咽部唾液作为标本在自动化即时分子检测中检测 SARS-CoV-2 的应用。对 58 例 COVID-19 患者的存档鼻咽拭子（NPS）和后咽部唾液标本进行了 Xpert Xpress SARS-CoV-2 检测。所有患者的 NPS 或唾液标本中均检测到 SARS-CoV-2。其中，84.5%（49/58）的 NPS 和唾液均为阳性，10.3%（6/58）的 NPS 为阳性，5.2%（3/58）的唾液为阳性。NPS 和唾液的检测率无显著差异（McNemar 检验 = 0.5078）。N2（NPS 为 94.8%，唾液为 93.1%）的检测率略高于 E 基因靶标（唾液：89.7%对 82.8%）。在两种标本类型上，NPS 的中位 Ct 值均明显早于 E 基因和 N2 基因靶标（NPS：26.8 对 29.7， = 0.0002；N2：29.3 对 32.3， = 0.0002）。E 基因靶标的中位 Ct 值明显早于 N2 基因靶标，无论是在 NPS（26.8 对 29.3， < 0.0001）还是唾液（29.7 对 32.3， < 0.0001）。总之，在后咽部唾液和 NPS 中发现即时检测 SARS-CoV-2 的检测率相似。由于后咽部唾液易于采集，建议将唾液作为 SARS-CoV-2 检测的替代标本类型。
