Testing for COVID-19: When should I get a COVID-19 Rapid Antigen Test?
The development of rapid antigen tests for COVID-19 has enabled wide populations to test themselves as often as they might need. Altogether, rapid antigen tests complement molecular methods such as PCR by providing more frequent, convenient, accessible, and faster diagnostics for COVID-19. Still, as we start to reopen public spaces including parks, museums, airports, or restaurants and return to our activities before the pandemic, the growing number of options for testing, it may be challenging for people to determine the most suitable option for them and get the most of it. Below, you can find the answers to some of the frequently asked questions about COVID-19 rapid antigen tests to help you decide whether this option is suitable for you. You can also find details on who should use them, how to use them, and how to interpret your results.
Who Should Get A COVID-19 Rapid Antigen Test?
If you notice COVID-like symptoms such as fever, cough, tiredness, and loss of taste or smell; the most important thing to do is to take either of the two viral diagnostic tests as soon as possible. However, as rapid antigen tests are known to perform well in detecting symptomatic infections where the viral load is sufficient, many experts agree that taking a quick rapid antigen test might be the primary option for most people with symptoms. By taking a rapid antigen test, you can get reliable results in minutes in the comfort of your own home which reduces the risk of transmission and allows for immediate isolation.
The risk that these tests give a false positive result is extremely rare. If you test positive on a rapid antigen test, you can immediately start isolating to protect the people around you from the transmission of the virus. If your test is negative but your symptoms persist or worsen, you should either take an additional PCR test or perform serial antigen testing to rule out the possibility of an infection with SARS-CoV-2.
Indeed, growing evidence suggests that rapid antigen tests may be reliably used on asymptomatic patients or at the early phase of infection if they are performed at regular intervals. Therefore, if you have no access to PCR testing, by taking an antigen test 2-3 times per week, you can achieve a level of sensitivity (>95%) that is on par with a PCR test and determine your infection status even if you do not show any symptoms.
How Often Should I Use COVID-19 Rapid Antigen Tests?
Serial antigen testing is also a reliable and convenient method for regular surveillance in a wide range of institutions including offices, industry settings, schools, airports these tests enable easier and quicker distribution, application, procession, and interpretation. Therefore, if you are looking for a quick, reliable, cost-effective, and convenient way to facilitate regular testing for your business, for example, serial antigen testing may be the best option for you.
Taking a rapid antigen test may also be the better option when time is of essence. In the case of an emergency where you need immediate results, taking a PCR test and waiting for your results to arrive may not be possible. In that case, taking a rapid antigen test may help you check you check your infection status and receive results in 15 to 30 minutes.
When Should I Get A COVID-19 Rapid Antigen Test?
Rapid antigen tests can also be useful for regularly monitoring ourselves as we go through our daily lives to protect ourselves and the people around us. If you have attended a crowded meeting or activity where the risk of viral exposure is high, you can take a rapid antigen test 3 to 5 days after the time of exposure to check your infection status and make sure that you are not infectious.
Especially if you are planning to visit friends or relatives that are at high risk of developing severe disease, you could use a rapid antigen test just before the event to make sure that you would not spread the virus. In that case, the time of testing should be as close as possible to the event to provide you with the most up-to-date information on your infection status.
If you are planning to travel, you might have to take a rapid antigen test before your trip depending on the criteria of the specific location that you are visiting. Likewise, some businesses, schools, and universities may require a negative test to allow your return after a SARS-CoV-2 infection and may accept rapid antigen test results. Still, as the criteria may chance depending on the location and institution, make sure to check the specific testing requirements.
Should I Also Swab My Throat When Taking a COVID-19 Rapid Antigen Test?
Although there is some early evidence to suggest that saliva swabs may be better than nasal swabs at detecting Omicron, many experts agree that individuals should only perform the test as instructed. If swabs designed for the collection of nasal specimens are used for the collection of throat sampling, they can give inaccurate results or even cause harm to the patient. As relevant data and literature grow, the technology and the guideline may be revised in accordance, however, in the meantime, following all instructions carefully remains crucial for safety and test performance.
What Do My COVID-19 Rapid Antigen Test Results Mean?
Like PCR tests, rapid antigen tests can only inform you on whether you have an active infection with SARS-CoV-2. The results of your rapid antigen test constitute a snapshot of your current infection status. If both the control line (C) and the test line (T) are visible, your test is positive, meaning that you are actively infected with SARS-CoV-2 and likely to transmit the virus. If only the control line (C) appears, your test is negative, which does not rule out the risk of infection altogether but suggests that you are less likely to transmit the virus even if you are infected. As mentioned above, taking an additional PCR test, or performing serial testing after your initial test can help rule out the risk of infection. Finally, if the control line (C) does not appear, the results are invalid.
- Centers for Disease Control and Prevention. (2020, February 11). Guidance for antigen testing for SARS-CoV-2 for healthcare providers testing individuals in the community. https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antigen-tests-guidelines.html
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