Laboratory testing for SARS-CoV-2 (COVID-19) ​

Through autumn and winter there are always a large number of different respiratory viruses circulating in the Australian community. In this context, however, the pre-test probability that a person has COVID-19 should determine whether a test is performed.

Testing has two important functions:

• confirm diagnosis and assist in management of patients with COVID-19
• to assist in the public health effort to limit the spread of COVID-19.

Prioritisation of testing for clinical management

Prioritisation of case testing, using Rt-PCR on nasal swab samples, has been developed and implemented. 

Prioritisation of testing for public health purposes

Early detection of COVID-19 is always important and in certain institutional and community settings it can significantly change management. Settings where this is considered to be important include:

• aged care facilities
• residential care facilities
• correctional facilities
• other institutions
• remote Aboriginal communities

Testing can determine whether an outbreak is in progress. Where a positive test would significantly change the management of an infection outbreak, then these tests should be prioritised.

Prioritisation of testing to maintain essential services

Currently all agencies and businesses are advised to facilitate working from home. Further, workers located on work premises should be checked each day and sent home if unwell. Social distancing must be facilitated in the workplace. Where prolonged close contact is inevitable appropriate PPE should be worn.

These two practices, i.e. social distancing and use of personal protective equipment, should significantly control the likelihood of disease transmission at work and thus minimise the requirement to perform staff testing to maintain essential services. Where a public health or clinical need is evident then testing should be prioritised.

How to prioritise testing for public health purposes

1. The samples need to be identified as high priority at the time of collection. Where possible testing, for these prioritised samples, should be performed at a NSW Health Pathology Laboratory.
2. The sample needs to be correctly labelled
   Clearly mark (written plus yellow highlighter marker) both the sample container and request form as urgent, with category:
   1. “Urgent – ICU inpatient”
   2. “Urgent – ED inpatient”
   3. “Urgent – Ward inpatient”
   4. “Urgent – Healthcare Worker”
   5. ”Urgent – Public health outbreak control”
   6. “Urgent – Essential Services Workers” (e.g. Police)
3. Send the sample and request form to your local hospital laboratory as soon as possible following agreed transport procedures.
4. Call your NSWHP hospital laboratory using Central Specimen Reception (CSR) contact details and identify the specimen as needing urgent transport to the nearest dedicated COVID-19 testing laboratory.
5. Results notification procedures are provided as follows:
   1. Positive results are managed by pathology services as a ‘High Risk Result’ and reported immediately to the local Public Health Unit and referring doctor, who are responsible for notifying the patient.
   2. Negative results will be notified to the patient as per normal local laboratory procedures or if the patient has registered in an assessment clinic via SMS.
   3. In the unusual circumstances where the material is unsuitable for testing or the test has been technically compromised the notification for repeat testing will be managed by the referring clinical or public health service staff.