Self-Collection of Nose and Throat Swab Samples for SARS-CoV-2 Antigen Testing

The emergence of new variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised questions about the accuracy of currently available rapid antigen detection tests (RADTs) for the detection of variants using the currently authorized sampling methods. Six Canadian provinces and 2 international jurisdictions have recommended dual throat and nose swabbing when performing a RADT in response to the emergence of the Omicron variant. The evidence used to support these decisions was not clearly reported.

Three pre-print, non-peer reviewed publications were identified regarding the diagnostic accuracy and clinical utility of RADTs using dual nasal and throat self-collected samples. Findings indicate that using combined nasal plus throat, instead of nasal samples alone, resulted in greater detection rates without having an impact on true negative rates. Combined sampling was associated with high acceptability and tolerability, ease of use, and low incidence of harms. However, the limitations of these publications should be taken into consideration when interpreting the findings. None of the relevant studies included children younger than 16 years old.