Yu C, Li L, Tuerson Y et al. Oropharyngeal secretion as alternative for SARS-CoV-2 detection. J Dent Res 2020; DOI: 10.1177/0022034520940292.

The nasopharyngeal swab test has a risk of sending home more patients (59%) who still have the infection, while the oropharyngeal secretion test will make such an error in fewer patients (14%).

This study determined if sampling of oropharyngeal secretions (OSs) helped improve detection of SARS-CoV-2 RNA by nucleic acid amplification testing of potential patients with COVID-19. The first prospective study consisted of 75 patients with COVID-19 who were ready for discharge and who had 2 consecutive negative results per nucleic acid amplification testing (NAAT) of viral samples retrieved with nasopharyngeal swabs (NPSs). The NAAT results of paired OS and NPS samples from 50 additional recruits with COVID-19 during their recovery stage were used in a second prospective study to compare the diagnostic values of the 2 viral RNA sampling methods. OSs obtained from 2 of the 75 participants in the first study yielded positive results for SARS-CoV-2 nucleic acid. Subsequent chemiluminescence enzyme immunoassays indicated that they were positive for the SARS-CoV-2 IgM and IgG antibodies. For parallel NAAT of OS and NPS samples in the second study, McNemar's test indicated that the difference between the frequencies of inconsistent parts of OS and NPS was statistically significant.