Self-collection: an appropriate alternative during the SARS-CoV-2 pandemic

Wehrhahn, Michael C; Robson, Jennifer; Brown, Suzanne; Bursle, Evan; Byrne, Shane; New, David; Chong, Smathi; Newcombe, James P; Sivertsen, Terri; Hadlow, Narelle

BACKGROUND Swabs for SARS-CoV-2 are routinely collected by health care workers, putting them at risk of infection and requiring use of personal protective equipment (PPE). Self-collected swabs offer many advantages provided detection rate of SARS-CoV-2 and other respiratory viruses is not compromised. METHODS In a prospective study, patients attending dedicated COVID-19 collection clinics were offered the option to first self-collect (SC) nasal and throat swabs prior to health worker collection (HC). Two different laboratory services participated, with HC at Site 1 collecting nasal and throat swabs and at Site 2 nasopharyngeal (NP) and throat swabs. Samples were analysed for SARS-CoV-2 as well as common respiratory viruses. Concordance of results between methods was assessed using Cohens kappa (κ). RESULTS Of 236 patients sampled by HC and SC, 25 had COVID-19 (24 by HC and 25 by SC) and 63 had other respiratory viruses (56 by HC and 58 by SC). SC was highly concordant with HC (κ = 0.890) for all viruses including SARS-CoV-2 and more concordant than HC to positive results by any method (κ = 0.959 vs 0.933). CONCLUSIONS Self-collection of throat and nasal swabs offers a reliable alternative to health worker collection for the diagnosis of SARS-CoV-2 and other common respiratory viruses. High viral load of SARS-CoV-2 throughout the respiratory tract and sensitive molecular methods may explain these findings. Self-collection also provides patients with easier access to testing, reduces the exposure of the community and health workers to those undergoing testing and reduces the requirement for PPE.