Saliva as a possible tool for the SARS-CoV-2 detection: A review

BACKGROUND: Salivary tests for the new coronavirus (SARS-CoV-2) diagnosis have been suggested as alternative methods for the nasopharyngeal and oropharyngeal tests. METHOD: Two reviewers independently performed a search in the following electronic databases: PubMed, Medline, Cochrane Library, Web of Science, Embase and Scopus to identify cross-sectional and cohort studies that used saliva samples for SARS-CoV-2 detection. The search strategy was: (“saliva”) and (“SARS-CoV-2” or “coronavirus” or “COVID-1”). RESULTS: A total of 363 studies were identified and 39 were selected for review. Salivary samples for SARS-CoV-2 detection was as consistent and sensitive as the nasopharyngeal swabs in most studies, having been effective in detecting asymptomatic infections previously tested negative in nasopharyngeal samples. Viral nucleic acids found in saliva obtained from the duct of the salivary gland may indicate infection in that gland. Live viruses could be detected in saliva by viral culture. CONCLUSIONS: Salivary samples show great potential in SARS-CoV-2 detection and may be recommended as a simple and non-invasive alternative.