ABSTRACT

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 p = 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, p = 0.0002) and N2 gene target (29.3 vs 32.3, p = 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, p < 0.0001) and saliva (29.7 vs 32.3, p < 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.

摘要

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检测，特别是在社区中。在这项研究中，我们评估了使用后口咽唾液作为自动护理点分子检测中SARS-CoV-2检测的标本。58 COVID-19的患者存档鼻咽拭子（NPS）和后口咽唾液标本与所述的Xpert测试^®随心SARS-CoV的-2测定。在所有患者的NPS或唾液标本中均检测到SARS-CoV-2。其中，在NPS和唾液中均呈阳性的占84.5％（49/58），仅在NPS中呈阳性的占10.3％（6/58），仅在唾液中呈阳性的5.2％（3/58）。NPS和唾液之间的检出率没有显着差异（McNemar's testp  = 0.5078）。在两个样本类型上，N2的检出率（NPS为94.8％，唾液为93.1％）略高于E基因靶标（唾液：89.7％对82.8％）。与E（26.8 vs 29.7，p  = 0.0002）和N2基因靶标（29.3 vs 32.3，p  = 0.0002）的唾液相比，NPS的中位数Ct值明显更早。NPS（26.8 vs 29.3，p  <0.0001）和唾液（29.7 vs 32.3，p）的E基因靶标的Ct中值显着早于N2基因靶标的Ct值 <0.0001）。总之，在SARS-CoV-2检测的即时检验中，发现口咽后唾液和NPS具有相似的检测率。由于可轻易收集口咽后唾液，因此建议使用唾液作为SARS-CoV-2检测的替代标本类型。