In the cold season, more and more people are at risk of getting sick with respiratory illnesses and flu, in addition to COVID-19. The symptoms are so similar between these conditions that people can’t immediately tell what kind of infection they have, just by looking at them. That’s where the tests like Flu test and covid test come in. By testing, patients can quickly find out what disease they have and act accordingly.
At the moment, there are several types of tests. But they are not the same and they cannot be carried out under the same conditions. To make the best choice, you should contact a clinic for covid testing in Long Beach or your nearby area to find more personalized information. In the meantime, we’ll analyze the testing methods one by one to see the advantages and disadvantages of each option.
Real Time PCR testing
Testing of suspected COVID-19 can be done either by RT-PCR or with rapid antigen testing, both of which are confirmatory tests. However, it’s recommends that rapid tests based on antigen detection should only be used in two situations: direct contacts with confirmed cases and asymptomatic institutionalised persons. In the other situations: symptomatic persons, symptomatic persons with a negative SARS-CoV-2 antigen test result, symptomatic direct contacts with confirmed cases, patients up to 48 hours before surgery and other categories of people, RT-PCR testing is recommended.
What does the test measure?
Polymerase Chain Reaction, or PCR, is a molecular technology that amplifies the ribonucleic acid (RNA) of COVID-19 – the genetic essence of the virus.
How is it performed?
For this test, secretions are collected from the nasal pharyngeal area, where the sinuses meet the throat. This is where the greatest amount of virus is found. The nurse inserts a cotton swab stick into the end through a nostril, stopping in the nasal pharyngeal area. To harvest the swab, it must be swirled in the cavity for 10 seconds, a manoeuvre that can cause discomfort to the patient.
How long does it take to get the result?
It’s possible to get the results in the same day but it might take longer in certain cases.
Benefits: This test is considered the gold standard for COVID-19 and is the safest. The virus is detected even if it is not present in large amounts in the body, as well as if the patient has no symptoms at all. It is also the test that everyone needs when travelling abroad.
It has relevant results at any time of the disease: from contact, as well as during the course, with or without symptoms.
It is a quantitative test – i.e. it identifies the amount of virus in the sample taken.
Disadvantages: the test is inconvenient and takes several hours to get the result.
Rapid tests based on antigen detection
What does the test measure?
Antigen-based tests are the fastest COVID-19 tests, which look for coronavirus proteins (viral antigens) in nasopharyngeal secretions taken from the possibly infected person.
The rapid antigen test should be performed no more than 5 days after the date of onset or no more than 7 days after the date of exposure. If the date of exposure is unknown, the rapid antigen test should be performed as soon as possible.
How is it performed?
Sampling is done in the same way as for RT-PCR testing, but this time samples are not taken from the throat but only from the nasal area. The test is more effective if the patient is in the acute phase of the disease. The sample obtained is placed on a strip of paper where SARS-CoV-2 antibodies are already present. If the virus is present, there will be a visible reaction between the antibodies on the paper and the viral antigens.
How long does it take to get the result?
The result is obtained within 15 to 30 minutes. The test looks and works like a pregnancy test. One line means there is no virus in the sample and two means the result is positive.
Advantages: Results are rapid and indicate infection even in asymptomatic people. In addition, the test is very easy to use.
Disadvantages: This test is more suitable for screening. The results are less sensitive for COVID-19 and therefore have a higher false negative rate. In contrast, the test is very specific, so if it is positive, you have COVID-19.
Antibody tests
What does the test measure?
Antibody tests or serological tests determine whether a patient’s immune system has produced antibodies to protect against the virus. As the body’s response can be different from person to person, and antibodies can be produced at a flexible distance from the time of infection, these tests are not reliable.
How is it performed?
This test is done by taking a blood sample which is tested for the presence of antibodies.
How long does it take to get the result?
In the case of an antibody test, the result can be found out the same day.
Benefits: Antibody testing can indicate whether you have been infected with COVID-19. It can also help diagnose post-infection complications such as multisystem inflammatory syndrome in children.
Disadvantages: mild cases of COVID-19 may not trigger the development of detectable antibodies. So a negative antibody test does not necessarily rule out a previous infection. Research to date has not yet led to a concrete answer about the time of antibody development after infection.
