Is saliva a reliable biofluid for the detection of COVID-19?

This review aimed to assess the current evidence on the diagnostic potential of saliva regarding the detection of coronavirus disease 2019 (COVID-19). The literature published until May 24, 2020 was searched in the Web of Science, PubMed and Google Scholar databases with the keywords "COVID-19", "SARS-CoV-2", "2019-nCoV", "oral fluid", "saliva", and "diagnosis", individually and in combination, and 11 studies that explored the efficacy of saliva in the diagnosis of COVID-19 in different patient groups were found. Together, these studies suggest that saliva is a safe and reliable tool for the diagnosis of COVID-19. Further, saliva offers enhanced safety as well as logistical and economic benefits as compared to the current methods used to diagnose COVID-19. However, there is still limited evidence in the literature to make a definitive, clinically appropriate decision. The ideal specimen for the detection of acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still an issue under investigation. Thus, new studies with large sample sets for the validation of easy, safe and reliable methods applicable for large-scale testing are immediately required.