A rapid antigen test detects proteins from SARS-CoV-2, the virus that causes COVID-19, in a sample. You can collect the sample yourself at home using a nasal swab or saliva.
Rapid antigen tests can be done anywhere by any reasonably competent person. Depending on the test, you can get a result in about 15 minutes, versus hours to days for a PCR result.
However, PCR test tests are less reliable than rapid antigen tests. You are more likely to get false negatives (the test indicates you don’t have COVID-19 when you do), or false positives (the test suggests you have it when you don’t). However, the accuracy of rapid antigen tests improves if you do them when you have symptoms or within seven days of a potential exposure.
Why utilise one?
Rapid antigen tests are helpful if you need to find out immediately if you have COVID-19. For instance, you could wish to protect elderly or vulnerable relatives who will be attending a family gathering that you are planning. If you exhibit symptoms of COVID-19 and cannot obtain a PCR test very away, you may also perform a fast antigen test.
How do you perform tests?
There are test instructions (and a QR code linking to a video). To get an accurate outcome, you must adhere to the directions strictly.
Depending on the test type, you will take a sample of saliva or nasal secretions and put it into a chemical solution. The sample-containing chemical solution is then applied to an indicator device akin to a pregnancy test. The change in colour here indicates a successful outcome.
Some vital tips to get accurate results
These pointers were derived from analysing the TGA website’s instructions for using authorised quick antigen tests. Here are some vital tips to get appropriate results;
1. Check the expiry date. Don’t use a test that has expired.
2. Some tests must be at room temperature for 30 minutes before use. So plan ahead.
3. If you are using a nasal swab, blow your nose before collecting the sample. If using a saliva test, don’t eat or drink for 10 minutes before collecting the sample.
4. Avoid contaminating the sample. Regardless of which test you use, instructions can ask you to clean a flat surface, wash or sanitise and dry your hands; and lay out the test items. Never touch the business end of the swab (the soft end that goes in your nose), as you will contaminate it.