Comparison of saliva and oro-nasopharyngeal swab sample in the molecular diagnosis of COVID-19

Abstract

BACKGROUND: Healthcare personnel are at risk of becoming infected while taking upper and/or lower respiratory tract specimens. Therefore, there is a need for sampling methods that do not risk infecting them. In this study, we aimed to compare the saliva and Oro-Nasopharyngeal Swab (ONS) sampling methods. METHODS: Patients were divided into three groups. Group 1 included patients whose diagnosis of COVID-19 was confirmed by polymerase chain reaction (PCR). Group 2 included patients with COVID-19 compatible findings in lung computed tomography (CT), but with a negative PCR. Group 3 included patients who presented to the emergency department with COVID-19 compatible complaints but had normal CT Saliva and ONS samples were taken on the third day of hospitalization in groups land 2, whereas in group 3, they were taken at the time of admission to the hospital. RESULTS: A total of 64 patients were included in the study. The average age was 51.04 +/- 77.9 years, and 37 (57.8%) were male. SARS-CoV-2 was detected in 27 (42.2%) patients' saliva samples. While the sensitivity and positive predictive value of saliva samples were 85.2%, specificity and negative predictive value were 89.2%. The value of kappa was in substantial agreement (0.744), and it was found statistically significant (<0.001). CONCLUSIONS: Saliva samples can be used instead of ONS samples in detecting SARS-CoV-2. Investigating SARS-CoV-2 with saliva is cheaper, easier for the patient and overall, and, most importantly, it poses much less risk of SARS-CoV-2 contamination to health-care personnel.