What is the difference between RT-PCR and the rapid antigen test?

COVID-19 tests are available in a variety of configurations on the market. We explore the many types of tests and how they can benefit you the most.

You might have heard a lot recently about coronavirus testing. With a variety of tests available today, which one is the best for you, your family, or your business? We distinguish three types of COVID-19 testing in this section.

Rapid Antibody Test

The fast test detects antibodies against SARS-Cov-2, the virus that causes COVID-19, in your blood. The test determines whether you have been exposed to the coronavirus, whether you have recovered from the condition, and whether you are capable of infecting others.

rapid antigen test

Because the quick test looks for antibodies produced by the immune system in reaction to a threat, it is often referred to as an antibody test. After an infection, antibodies may take weeks or months to develop and may remain in your blood for several weeks. As a result, these tests should not be utilised to determine whether you have COVID-19 in your system.

Antigen Examination

Antigen testing utilise nose or throat swabs to detect certain proteins. It is capable of diagnosing a coronavirus infection that is active. Although positive antigen test findings are regarded very accurate, they do not entirely rule out coronavirus infection. To obtain the most precise data, you must have a swab test or reverse transcription polymerase chain reaction (RT-PCR) test.

RT-PCR —Test

The RT-PCR (reverse transcription-polymerase chain reaction)* test, which uses nasal or throat swabs, determines whether a person has the virus. This test will be recommended based on the results of the antibody or antigen test performed on the subject. The RT-PCR test is the most precise of the three and often does not require repeating.

Frequently Asked Questions

Who should be COVID-19 tested?

Individuals who exhibit COVID-19-related symptoms should consider testing, depending on local health restrictions.

Additionally, you may require testing even if you do not exhibit symptoms if you:

  • have had close touch with a person who tested positive for the virus;
  • work in a hospital or as first responders;
  • reside or work in long-term care institutions, such as nursing homes, or in other densely populated areas, such as homeless shelters;
  • require medical treatment or are currently receiving care at a hospital or long-term care institution; or
  • require clearance before to travel or employment.

What form of test is utilised to determine whether a person is currently infected with COVID-19?

Two tests can determine whether you are currently infected with COVID-19:

RT-PCR (the Gold Standard):

this is the most accurate test, but results may take 24-72 hours, or in certain situations, even longer, to get due to the necessity for samples to be tested in a properly equipped laboratory.

Antigen tests:

these tests are typically faster, returning results in as little as 30 minutes, but are less reliable than the RT-PCR test. This means that the test may miss some infections, and some patients infected with the COVID-19 virus may receive a negative result (called a false-negative test). Similarly, an individual who has been infected with a virus other than COVID-19, such as the common cold virus, may test positive for COVID-19 (called a false-positive test).

If you have a choice, opt for the RT-PCR test because it provides more accurate results.

An antibody test may also be offered in some countries. This test determines whether you have had COVID-19 in the past and should NOT be used to determine if you have an active infection. Antibody testing determines whether your blood has a specific protein created when your body fights a virus such as COVID-19 from a previous infection. However, there is a possibility that a positive test indicates that you have antibodies to a virus in the same family as COVID-19, such as the one that causes the common cold.

While antibodies normally protect against re-infection, there is currently insufficient data to determine whether and how much protection COVID-19 antibodies may provide. Additionally, testing for antibodies does not guarantee that you will spread COVID-19, so it is critical that you continue to take precautions such as staying at home, keeping a physical distance from others, wearing a face covering, and isolating yourself if you develop symptoms.

How is the examination conducted? Is it agonising?

To gather an appropriate sample of mucus for RT-PCR and antigen tests, a doctor, nurse, or lab technician inserts a thin, flexible stick with cotton at the tip into your nose. The swab is held in place for several seconds before being gently rotated out and sealed in a tube for analysis in a laboratory. Swabs from both nostrils may be necessary to gather enough mucus for the test. This can be slightly inconvenient but is not particularly painful.

A blood sample is required for antibody testing.

How long does it take to receive the results of the test?

The time required to obtain your findings is determined by the type of test used. Certain testing centres and clinics offer antigen testing, which means that you can have your findings within an hour or on the same day as the test. Other centres utilise a real-time polymerase chain reaction (RT-PCR) test, which requires samples to be sent to an external laboratory for examination. If this is the case, it is possible that your findings will not be available for many days. Whichever test is employed, you should self-isolate or quarantine yourself while awaiting the findings.

What should I do if I receive a positive test result?

A positive test result indicates that you are most likely infected with COVID-19 at this time and should self-isolate: stay at home, isolate yourself from others, and take precautions to avoid spreading the virus, such as wearing a face mask and practising proper hand hygiene and physical distancing. If your symptoms worsen, call your local health care practitioner.

Once all of your symptoms have resolved and you have finished your prescribed isolation period, you do not need to get tested again.

If you share a household with other family members, it is critical that they take care to avoid becoming infected and transmitting the virus. All family members who exhibit COVID-19-related symptoms should also be evaluated and self-isolated until their symptoms improve.

What should I do if my test results come back negative?

A negative test result indicates that you are highly unlikely to have COVID-19. You should maintain proper hand cleanliness, physical separation, and the wearing of a facial covering. This is critical if you are experiencing symptoms, as it is possible that you have the virus but the test did not find it. If you believe you tested negative but are actually infected, speak with your health care physician about having another test performed.

Can someone test negative for COVID-19 and then test positive?

Yes, either because the test failed to detect the virus or because you contracted the virus after taking the test.

Is it possible for someone to test positive by mistake?

It is uncommon for someone to receive a false-positive result from the reverse transcription polymerase chain reaction (RT-PCR) or the antigen COVID-19 diagnostic tests. If you have tested positive, it is vital that you isolate yourself to avoid spreading the infection.

Where should you go for COVID-19 testing?

Most countries have COVID-19 testing centres to facilitate diagnosis. To obtain information on testing facilities in your neighbourhood, please contact your local Health Board or government health office.

Is there a global test scarcity at the moment?

Given the global spread of the COVID-19 pandemic, RT-PCR diagnostics have been in short supply. As a result, local governments may provide preference to people who have access to testing.

What is the cost of a COVID-19 test?

The cost varies by nation. Your physician or local clinic can provide more precise information regarding the cost of COVID-19 testing in your area.