SARS-CoV-2 Detection via RT-PCR in Matched Saliva and Nasopharyngeal Samples Reveals High Concordance in Different Commercial Assays

• Published in: Diagnostics (Basel) Vol. 13; no. 2; p. 329
• Main Authors: de Sousa, Karoline Almeida Felix, Nonaka, Carolina Kymie Vasques, de Ávila Mendonça, Renata Naves, Mascarenhas, Verena Neiva, Weber, Thamires Gomes Lopes, Regis Silva, Carlos Gustavo, Mendes, Ana Verena Almeida, Khouri, Ricardo, Souza, Bruno Solano Freitas, Gurgel Rocha, Clarissa Araújo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 16-01-2023; MDPI
• Subjects: Agreements; Asymptomatic; Communication; Coronaviruses; COVID-19; diagnostic method; Emergency medical care; FDA approval; Gene amplification; Hospitals; Laboratories; RT-PCR; saliva; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Software; Brazil; United States > US; South Korea; COVID-19; saliva; SARS-CoV-2; diagnostic method; RT-PCR
• ISSN: 2075-4418; 2075-4418
• DOI: 10.3390/diagnostics13020329

Self-collected saliva samples can increase the diagnostic efficiency and benefit healthcare workers, patient care, and infection control. This study evaluated the performance of self-collected saliva samples compared to nasopharyngeal swabs using three commercial kits for the qualitative detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Matched nasopharyngeal and saliva samples were collected from 103 patients with either asymptomatic or symptomatic COVID-19. Both samples were evaluated using three commercial kits (TaqCheck, Allplex, and TaqPath). To evaluate sample stability, viral RNA extraction was performed in the presence or absence of an RNA-stabilizing solution. Storage conditions, including the duration, temperature, and stability after freezing and thawing of the samples, were also evaluated.
All the saliva samples showed 100% concordance with the nasopharyngeal swab results using TaqCheck and Allplex kits, and 93% using TaqPath kit. No difference was observed in the samples that used the RNA-stabilizing solution compared to the group without the solution. The
values of the freeze-thawed samples after 30 days were higher than those on day 0; however, the results were consistent the fresh samples.
The high concordance of SARS-CoV-2 detection via reverse transcription-polymerase chain reaction (RT-PCR) in matched saliva and nasopharyngeal samples using different commercial assays reinforces the concept that self-collected saliva samples are non-invasive, rapid, and reliable for diagnosing SARS-CoV-2 infection.