Comparison of Mouthwash and Naso-Oropharyngeal Swab Samples in the Diagnosis of COVID-19

Abstract

Introduction: In this study, we aimed to compare the place of throat mouthwash in the diagnosis of COVID-19 and the detection values of SARS-Cov-2 in naso-oropharyngeal swab (NOS) and mouthwash samples. Materials and Methods: NOS and mouthwash water samples were taken from the patients simultaneously. Mouthwash sampling was obtained by himself. For the NOS sample; after the swab sample was taken from the patient's oropharynx with a dacron tip swab, with the same swab. RNA isolation from combined oral/nasal swab samples was performed with the EZ1 (Qiagen, Germany) device. Statistical analyses were performed using the SPSS software version 21.0. Results: The diagnostic efficacy of throat mouthwash and combined NOS samples taken from 106 volunteers were compared (56 males, mean age 42.9 years). The diagnostic sensitivity of the mouthwash was 60.71%, specificity 98.65%, positive predictive value 94.44% and negative predictive value 86.9% compared to the results of the NOS. According to these results, although mouthwash is a specific test, its sensitivity to NOS is not satisfactory. The value of kappa was substantial agreement as 0.668, and it was found statistically significant (<0.001). Conclusion: Throat mouthwash is a promising noninvasive technique for diagnosis, monitoring and infection control in patients with COVID-19 infection and reduces the risk of transmission for the healthcare provider.