As the number of coronavirus cases are surging in 2021, governments of various countries are expediting the speed of Covid-19 testing. There are plenty of tests, like the PCR Covid-19 swab test same day, molecular tests, and antigen tests, that can detect the presence of infection.

What happens to those who develop Covid-19? 

Among those who develop the symptoms of Covid-19, most recover without needing hospital treatment. However, about 15% of people become seriously ill and require oxygen, and 5% become critically ill and need intensive care treatment. In addition, some complications may lead to death including respiratory failure, acute respiratory distress, thromboembolism, septic shock, multi-organ failure as well as injury to the heart, liver or kidneys.

Different types of testing for Covid-19 

There are various types of Covid-19 testing available that can tell you about current and past infections.

Molecular tests for Covid-19

This test for Covid-19 is used to help diagnose a current infection. It is also referred to as a:

  • Reverse transcription-polymerase chain reaction test (RT-PCR test).
  • Reverse transcription loop-mediated isothermal amplification test (RT-LAMP test).
  • Nucleic acid amplification test (NAAT).

How is the test done?

Molecular tests use a special probe to identify the presence of genetic material of the coronavirus. Many molecular tests can detect the presence of multiple viral genes instead of just one for better accuracy. This test includes collecting a sample using a nasal or throat swab. Some types of the Covid-19 PCR swab test can be performed with a saliva sample, obtained by asking you to spit into a tube. You can receive molecular tests in many locations, including:

  • Hospitals.
  • Healthcare centres.
  • Urgent care centres.
  • Community-based Covid-19 testing sites.
  • Pharmacies.
  • At home.

Turnaround time for a molecular test can vary. For instance, results can be received in 15 to 45 minutes using a point of care test. The molecular test is recognized to be the gold standard for diagnosing Covid-19. Due to this, a positive result on a molecular test is often adequate to diagnose Covid-19, especially if you also have Covid-19 symptoms. You don’t need to repeat the test after you have received the results.

  • Testing too early: it requires up to 5 days before the virus’s genetic material can be identified after exposure. Thus, you may receive a false-negative result if you get tested within this time frame.
  • Testing too late: viral infection in the upper respiratory region begins to fade after the first week of sickness. Because of this, getting tested too late can also give false-negative results.

Antigen tests for Covid-19 

An antigen test can be used to determine the presence of a current infection. This type of test is also known as a Covid-19 rapid test. It works by looking for specific antigens, which are protein markers found outside the SARS-CoV-2 virus.

How is the test done? 

If coronavirus antigens are identified, the antibodies used in the antigen test will attach to them, creating positive results. The specimen for this test is obtained using a nasal swab. The sample is sent to the laboratory but is normally analyzed on-site. They often provides results within 15 minutes. This test is primarily used in screening for and, in some cases, diagnosis of Covid-19.

Antigen tests are less reliable than molecular tests. Research has found that antigen tests correctly detected Covid-19 in 72% and 58% of people with and without Covid-19 symptoms, respectively. However, a positive result is normally quite reliable; a false-negative result can still happen for a same reasons to molecular tests. You may require a molecular test to confirm a negative result because of its low accuracy, especially if you currently have Covid-19 symptoms.

Antibody tests for Covid-19

 An antibody test helps to determine the presence of a past infection. This test is often known as a serology test or serological test. Currently, experts do not know whether the presence of antibodies implies that people are immune to Covid-19 or for how long the immunity will last. Therefore, for people who have received a Covid-19 vaccination, antibody testing is not recommended to decide whether you are immune or protected from Covid-19.

How is the test done?

This test detects the antibodies specific to Covid-19 in your blood. The antibodies are proteins that your immune system builds in response to infection or vaccinations. It takes about 1 to 3 weeks for your body to start producing antibodies so this test cannot determine the presence of current infection. A blood sample can be obtained through a finger stick for this test.

The turnaround time for antibody tests may change. Some healthcare facilities may give same-day results. If a specimen is sent to a laboratory for review, you can expect to receive your results in 1 to 3 days. Generally, the accuracy of the test improves as time passes. For instance, the test was:

  • 30% accurate one week after symptoms developed.
  • 70% accurate two weeks after symptoms develop.
  • More than 90% accurate three weeks after symptoms develop.

Healthcare experts are still learning exactly how long antibodies from a natural SARS-CoV-2 infection last. However, some research has found that antibodies can persist for at least 5 to 7 months in people who have recovered from Covid-19.

Home testing for Covid-19

Many Covid-19 home testing options are now available, including a PCR swab, antigen tests, and antibody tests.

In addition, there are two different types of home Covid-19 testing:

  • Home collection: in this type of testing, you collect the sample at home and then send it to a lab for further analysis.
  • At-home tests: these tests let you collect a sample and then test it at home with a given testing kit.

The type of sample obtained depends on the type of test. For example, viral home tests may need a nasal swab or a saliva sample. The home antibody test needs a blood sample from a finger stick. Covid-19 home tests kits are available with or without a prescription at a retail store, pharmacy or online store.

Follow the tips below if you are using a home test kit

  • Check the expiration date of the test before using it.
  • Don’t use the test kit if any item is damaged or missing.
  • Thoroughly read all the directions and follow them.
  • Before taking a test, wash your hands and disinfect the table where you will be taking the test.
  • Follow the step-by-step instructions to successfully carry out the test.
  • Properly dispose of testing materials after taking your test.
  • Reach out to a healthcare professional if you have any queries and doubts.

Vaccination and Covid-19 testing

Receipt of a Covid-19 vaccine should not affect the result of the SARS-CoV-2 viral test. Because the Pfizer-BioNTech, Moderna and Johnson & Johnson Covid-19 vaccines use the SARS-CoV-2 spike protein to generate an immune response, a positive antibody test for spike proteins could indicate either a previous infection or vaccination.

The bottom line

As the number of Covid-19 cases is increasing day by day, it is crucial to expedite testing to flatten the curve. So, these are some of the different types of testing methods for detecting Covid-19. Depending on your need, you can take these tests if you want to know about a current or past infection.