Investigation of saliva, tongue swabs and buccal swabs as alternative specimen types to nasopharyngeal swabs for SARS-CoV-2 testing

Throughout the ongoing SARS-CoV-2 pandemic, the recommended sample type for initial diagnostic testing for SARS-CoV-2 infection has been a nasopharyngeal swab. Shortages in swabs and difficulties in obtaining nasopharyngeal swabs in certain patient groups has prompted research into alternative specimen types for the diagnosis of COVID-19. The aim of this study was to assess how ‘simply collected’ saliva along with tongue swabs and buccal swabs preformed as an alternative specimen type for SARS-CoV-2 detection. It was observed that saliva samples allowed for the detection of 85.3% of positive patients, tongue swabs allowed for the detection of 67.6% of positive patients and buccal swabs allowed for detection of 20.8% of positive patients, when compared to nasopharyngeal swabs. From this data, it could be concluded that using simple saliva collection can provide a less invasive and reliable alternative method for the detection of SARS-CoV2 particularly in those patients where invasive sampling is difficult and where regular repeat testing is required.