Many of you continue to have doubts and questions about the well-known and commented “PCR test”, among other topics that we will be dealing with. Below, we answer 10 of the questions that have aroused the most interest during our patients’ consultations.
1. Why is it called COVID-19?
The name is an acronym for coronavirus disease 2019. The WHO announced on February 11, 2020 that COVID 19 would be the official name of the disease. The virus that causes the disease is SARS-CoV-2, the coronavirus type 2 of severe acute respiratory syndrome.
2. What is a PCR test and how is it performed?
It is a test that detects the presence of the genetic material of the SARS-CoV-2 virus. It is a test that replicates the virus genome through Polymerase Chain Reaction (PCR), a method that allows detecting a fragment of the genetic material of a pathogen. The PCR test achieves the detection of the coronavirus (its ribonucleic acid, RNA) soon in the early stages of the infectious process, regardless of whether there are no symptoms yet or will not develop them, as in the case of asymptomatic people.
In carrying out this test, it is necessary to collect a sample from the nasal portion of the pharynx -nasopharyngeal- and from the buccal portion of the pharynx -oropharyngeal- with a sterile swab which will be analyzed later in the laboratory.
3. How to interpret the results of a PCR test?
The PCR test detects the genetic material of the virus and is positive in the first phase of the disease: from incubation to the disappearance of symptoms. If the result of the PCR test comes out negative, there could be two scenarios: either the disease has not been passed or it has already passed, in which case, an antibody test should be done to confirm it: ELISA or the quick antibody test.
4. Are the results reliable?
The test we perform at Life Length has a 99.9% reliability. In our laboratory we detected 3 regions of the viral RNA: protein S (spike), protein N (nucleocapsid) and ORF1 ab. Other laboratories detect 1 or 2 regions of the viral RNA to save time or costs, and their results are much less reliable.
5. How long does it take to know the results?
The results of the PCR test are ready in 24 hours and will reach you by email. To perform the PCR test, special conditions of biological safety and technical capacity are required by qualified personnel in genetic analysis and it takes approximately 4 hours of work.
6.What is the difference between a PCR test and serological tests, ELISA and rapid antibody test?
The PCR test is capable of detecting the presence of the virus, the antibody detection tests are not. The ELISA test and the quick antibody test do not detect the virus but the immune reaction generated by our body against it, that is, they detect the antibodies produced against the virus by the person’s immune system. They are indirect proof that the disease is active or has passed.
7. What is RNA?
RNA is an acronym for ribonucleic acid. Nucleic Acid that participates in the synthesis of proteins and performs the function of being the messenger of the DNA genetic information and at the same time is the only genetic material of certain viruses (RNA viruses).
8. What is a serological test?
Serology is the study that checks the presence of antibodies in the blood. Some of the best known diseases that are detected with serology are measles, rubella, HIV, viral hepatitis, toxoplasmosis, etc. At Life Length we have two serological or antibody tests: the ELISA test, with results available in 24 hours and the quick antibody tests, with results available in just 15 minutes.
9. Should I combine a PCR test with other serological tests?
When a person decides to have tests, especially if they are asymptomatic, we advise to do both types of tests, the PCR test and another serology test, either the ELISA test or the rapid antibody test. The combination will tell us what stage of the disease we are in. In the first days after infection, the PCR test will be positive and the serology may be negative; later it will be the other way round: the serologies will be positive and the PCR test negative.
10. What is the price and where to do the PCR test?
The price of the PCR test for individuals is 150 euros per person. The PCR price combined with the quick antibody test is 199 euros per person and combined with the ELISA price, 215 euros.
You and your family can take the tests in Madrid, at our office on Miguel Ángel St.
Pictures: Jules Bss, Anthony Tran, National Cancer Institute