Identification of acute SARS-CoV-2 (COVID-19) infection is made by Nucleic Acid Testing (NAT) on respiratory tract sampling.
The sensitivity of testing depends on the stage of disease, the quality of sample collection, the nature of the swab used, and assay performance.
Self-collection of nose and throat swabs can be used for respiratory virus NAT. The validity of self-swabbing for influenza has been reviewed, and suggests reasonable sensitivity (pooled estimate 87%) compared to swabs taken by healthcare workers (HCWs).
This approach was suggested for use in influenza research and surveillance and studies. Throat washes and gargles have also been used for the diagnosis of SARS with reasonable efficacy (including monitoring hospitalised patients already known to be NAT positive), and also for influenza and respiratory tract bacteria.
Self-collection has been used in the current SARS-CoV-2 outbreak, particularly in busy screening clinics, or in the context of reduced availability of personal protective equipment (PPE). Laboratory validation of self- collected samples for the identification of SARS-CoV-2 is limited but shows reasonable concordance with HCW swabbing. Without care and training, self-collection in the home environment may pose issues of contamination of collection material and transport packaging.
Note: Decisions concerning self-collection should be made in response to clinical and public health imperatives with Public Health Unit advice.
Professor Dominic Dwyer, Director of Public Health Pathology, NSW Health Pathology (NSWHP)
Public Health Pathology
Version 3 - 01/05/20: Stephen Braye, Emergency Operations Centre Incident Controller, NSWHP