Rapid PCR testing (for clinical diagnosis)
Expanding rapid PCR testing has always been part of our testing strategy to help combat this pandemic.
Most testing will continue to be performed by one of our dedicated referral laboratories, but rapid testing is important in circumstances when a patient needs urgent care and there may be logistical or transport challenges from regional and rural facilities to metro labs.
Specialist diagnostic instrumentation needed for rapid PCR testing of COVID-19 is already in place across many of our labs and NSWHP has now carried out essential scientific evaluation of the new COVID-19 test cartridge for the GeneXpert platform.
Rapid PCR COVID-19 cartridges have been distributed to further regional sites and some metropolitan centres to support urgent testing needs.
The Microbiology Clinical Stream helped set the guidelines for the appropriate use of these tests and you can read more about our roll-out strategy and priority patient criteria here.
Rapid antibody test kits for COVID-19
There has been much media reporting about rapid test kits for COVID-19 in recent weeks, which has in some cases been misleading and caused confusion. Rapid testing is of course important, but understanding the facts behind the different tests (such as antibody versus antigen) and what they provide in terms of patient care and public health protection is equally vital.
Rapid antibody test kits for COVID-19 have very limited utility in diagnosis of an active case. They cannot show if someone is currently infected and at increased risk of becoming seriously ill or spreading the infection to others. Their utility in testing healthcare workers and high-risk groups in the current testing criteria is not yet established and advice from the Public Health Laboratory Network would counsel against widespread adoption.
Against the backdrop, NSW Health Pathology (NSWHP) has raised concerns about the quality and clinical utility of COVID-19 rapid antibody tests now on offer by a range of commercial vendors. NSWHP is undertaking a comprehensive scientific evaluation of a number of new rapid antibody test kits. In a first-of-a-kind evaluation in Australia by NSWHP, one such rapid antibody test kit has been shown to have limited value in diagnosing active cases and cannot reveal if someone is currently infected and at increased risk of becoming seriously ill or spreading the infection to others.
NSWHP has concluded this specific test kit could not be recommended for use in the diagnosis of acute infection, as a means of determining immunity in an individual, nor as a seroprevalence tool. More work is underway to assess reliability and application of the new test kits.
Read more on NSWHP’s position and evaluation here.
Rapid antigen testing discussion paper
It’s important we continue to monitor local and global independent literature as new types of COVID-19 tests are developed.
Most recently, COVID-19 rapid antigen tests (immunoassays that detect the presence of viral antigen specific to SARS-CoV-2) have become increasingly available. A positive result implies current infection.
On review, our clinical experts have concluded rapid antigen tests are not currently suitable for widespread use, given the availability and reliability of high throughput and rapid nucleic acid testing (NAT). This may change in defined specific-use cases as data on performance and assay availability and approval become available. However, they do not replace NAT as the preferred method for COVID-19 diagnosis.
Read more on NSWHP's discussion paper on the role of COVID-19 Rapid Antigen Testing (PDF 233.9KB).