Australia can Health Minister Greg Hunt wants COVID-19 rapid antigen tests to be available for home use as soon as they’re approved by the Therapeutic Goods Administration (TGA). Hunt hopes approval will come by Christmas, if not before.
This would allow Australians to test themselves for SARS-CoV-2, the virus that causes COVID-19, in their home and receive the results within half an hour.
As Australia moves to the next phase of managing COVID-19, these tests will become more commonplace. So what can we learn from their use overseas?
How do they work and how effective are they?
Traditional PCR tests amplify parts of the virus’ genetic code. PCR tests are performed on a swab of the nose and throat taken by health professionals. They’re then sent to a laboratory for analysis.
PCR tests are more sensitive than antigen tests: they can detect lower levels of the virus compared to antigen tests. However PCR tests can take hours, or occasionally days, for results.
Antigen tests, on the other hand, detect protein on the surface of SARS-CoV-2 directly from a sample. The sample can be a swab of the nose, but some use saliva samples.
Detecting COVID in people with no symptoms
Antigen tests play an important role in testing people who have no symptoms.
One of the largest studies from the United Kingdom, of almost 750,000 tests on 250,000 people in Liverpool, showed rapid antigen tests may be useful in diagnosing infections in people who have no symptoms.
These authors broadly categorised the reason for testing in three ways:
As part of this study, testing was performed in key workplaces, such as with emergency services workers and in schools. Results were promising, showing a 17.5% increase in detection of cases.
This increase in detection may assist in breaking chains of transmission. It’s important to remember that when testing people with no symptoms, rapid antigen tests are more likely than PCR tests to return false positives.
However, despite high rates of uptake, test users only returned a small proportion of these kits (8.3%) to health authorities.
How are other countries using them?
Singapore has recently distributed home testing kits to all households nationally, free of charge.
What do users think about these tests?
Attitudes to antigen testing have generally been positive. Those who participate in antigen testing most commonly cite “civic duty” and a desire to protect family and friends as the reason.
What is Australia’s regulator, the TGA, reviewing?
The TGA has recently invited sponsors of kits to submit information relevant to the use of home testing, including the use of software to capture results data.
The TGA’s requirements aim to protect the safety and privacy of users. They include ensuring:
- clear instructions for the user in the event of a positive result
- reporting of complaints relating to false positives and false negatives
- guarantees relating to data privacy and cybersecurity.
But these regulations don’t extend to verification of patients’ details or transmission of results to public health authorities.
People without symptoms, for example, could use home testing as an extra reassurance prior to visiting family or attending events.
The introduction of home testing for SARS-CoV-2 may also pave the way for home testing for other infectious diseases, such as sexually transmitted infections and influenza. This would be a paradigm shift in the way we detect and monitor infectious diseases in Australia.