Rapid Covid-19 self-testing kits: How they work

Australians will soon be able to access rapid antigen tests. Here’s everything you need to know about the Covid game-changer.

Australians will soon be able to access do-it-yourself Covid-19 tests after the federal government gave the go-ahead for green light for rapid antigen tests to be made available from November 1.

The tests, which provide a result in just 20 minutes, are already popular in the UK and US and widely available around the world.

A nurse conducts a Covid-19 test in Sydney. Picture: NCA NewsWire / Gaye Gerard

Health Minister Greg Hunt welcomed the convenient option, saying it would help Australians adapt to living safely with the virus.

“One of the critical parts of the national plan is to make sure that people will be able to go about their daily activities safely,” he said.

“So I am delighted that the TGA has now recommended that home testing will be available from the first of November.”

But it will be up to state and territory leaders whether they will allow at-home testing within their jurisdictions, Mr Hunt said.

Here’s everything you need to know about the tests that will change how we live with Covid-19.

WHAT IS A RAPID ANTIGEN TEST?

Conventional PCR tests identify genetic fragments of the virus that causes Covid in a nasal swab and are performed in complex laboratories and take hours, sometimes days to get a result.They are very accurate.

A medical assistant wearing protective mask, gloves and garment processes a sample from a rapid antigen test. Picture: AFP

Rapid antigen tests are a little like a home pregnancy test kit and are used to detect the presence or absence of viral proteins in a nasal or saliva swab. They are portable and can be performed at home.

HOW QUICKLY CAN YOU GET RESULTS?

You can get results in 15-20 minutes from some tests.

ARE THEY EASILY ADMINISTERED?

The test usually involves taking a nasal swab using a small cotton bud that is placed into a chemical solution. The solution is then dropped onto a reactive strip of paper in a plastic device similar to a pregnancy test. The device will generally display a line in the test window if you have COVID-19.

ARE THEY ACCURATE?

Rapid antigen tests are most accurate when used in the first few days of an infection and when people have Covid symptoms. A Cochrane review of the tests found the likelihood of a positive result if someone is infected with the virus but who had no symptoms was only between 40–74 per cent. This means many people tested may receive a negative test when they really have the virus. Some people may also get a false positive result.

Employees have rapid antigen tests in Bangkok. Picture: AFP

DO YOU STILL NEED A PCR TEST?

If a rapid antigen test shows you have Covid you will also need to have a PCR test as this is the gold standard test to diagnose the virus.

WILL RAPID ANTIGEN TESTS BECOME A PART OF THE HOME QUARANTINE STRATEGY FOR TRAVELLERS?

Yes. They are already being used in many countries to check incoming travellers. The Australian Government is also using the tests at its hotel quarantine station in the Northern Territory

IS THERE A RISK OF INEFFECTIVE AND SUB-STANDARD TESTS FLOODING THE MARKET, LIKE WE HAVE SEEN WITH MASKS? HOW WILL THE PUBLIC KNOW WHICH ONES TO USE?

The medical regulator the Therapeutic Goods Administration (TGA) has already approved 33 rapid antigen tests for use under medical supervision in Australia. It’s the job of this agency to make sure the tests used here are of high quality.

A drive-through testing clinic in Sydney. Picture: NCA NewsWire / Flavio Brancaleone

HOW MUCH WILL THEY COST?

Many overseas governments have made the tests available for free but Health Minister Greg Hunt said Australians would have to buy them at their local pharmacy. They cost between $10 and $100 overseas.

CAN YOU GET A RAPID ANTIGEN TEST NOW?

Yes. Many banks, transport companies and supermarkets are currently offering the tests to frontline employees as part of their Covid management strategy.

WHEN WILL YOU BE ABLE TO BUY A HOME TEST KIT?

Rules will change from November 1 to allow people to use the kits at home without medical supervision. However, no rapid antigen tests have yet been approved for home use. TGA boss Professor John Skerritt said the authority was hoping to approve home testing kits within the next month once the companies that make them put in applications and meet requirements to have an Australian contact number if they get a positive result or have any questions about the test.

WHAT ARE POTENTIAL PROBLEMS?

There is concern that some people who get a positive test result may not come forward for a PCR test or notify health authorities that they have an infection.

Originally published as Rapid Covid-19 self-testing kits: How they work