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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, nature of the swab used, quality of sample collected 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, saliva samples and gargles have also been used for the diagnosis of SARS-CoV-2 with reasonable efficacy. This includes monitoring hospitalised patients already known to be NAT positive, and for influenza and respiratory tract bacteria.

Self-collection of respiratory tract swabs 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.

Recommendations

1. In the context of identifying COVID-19 patients with maximal sensitivity with NAT, self-collected swabs and saliva samples are likely to be somewhat less sensitive than recommended HCW- collected upper respiratory tract swabs.
2. If self-collection is used, it would be best performed under the instruction of a HCW. Mid- turbinate and anterior nares swabs and saliva samples can be self-collected.
3. In the emergency department, wards and hospital environment, nasal/oral swabs are the preferred sample and should be collected by HCW using appropriate PPE.
4. Home self-collection is not the preferred option for sample collection, but may be considered in at-risk occupational screening.

Note: Decisions concerning self-collection should be made in response to clinical and public health imperatives with NSW Public Health Unit advice.

Document information

Developed by

Professor Dominic Dwyer

Consultation

• Stephen Braye
• Roger Wilson
• Rob Lindeman
• Nicole Tripney.

For use by

Local health districts, specialty health networks, other health providers and medical practitioners.