Background: Effective management of Severe Acute Respiratory Syndrome Coronavirus 2 requires large-scale testing to identify and isolate infectious carriers. Self-administered saliva and buccal swabs are convenient, painless and safe alternatives to the current healthcare-worker (HCW) collected nasopharyngeal swab (NPS).
Methods: A cross-sectional single centre study was conducted on 42 participants who were tested positive for SARS-CoV-2 via NPS the past 7 days. Real-time polymerase chain reaction (RT-PCR) was performed and cycle threshold (CT) values were obtained for each test. Positive percent agreement (PPA), negative percent agreement (NPA) and overall agreement (OA) were calculated for saliva and buccal swabs, and compared with NPS.
Results: Among the 42 participants, 73.8% (31/42) tested positive via any one of the 3 tests. With reference to NPS, the saliva test had PPA 66.7%, NPA 91.7% and OA 69.0%. The buccal swab had PPA 56.7%, NPA 100% and OA 73.8%.
Conclusion: Self-collected saliva tests and buccal swabs have only moderate agreement with HCW-collected NPS swabs. Primary screening for SARS-CoV-2 may be performed with a saliva test or buccal swab, with a negative test warranting a confirmatory NPS to avoid false negatives, minimize discomfort and reduce the risk of spread to the community and HCWs.
